ARTICLE | doi:10.20944/preprints201611.0128.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: time slice LC-SPE-NMR/MS; GC-MS; LC-MS/MS; triterpenoid saponins; Barbarea vulgaris
Online: 25 November 2016 (10:04:12 CET)
Recently the number of studies investigating triterpenoid saponins has drastically increased due to their diverse and potentially attractive biological activities. Currently the literature contains chemical structures of few hundreds of triterpenoid saponins of plant and animal origin. Triterpenoid saponins consist of a triterpene aglycone with one or more sugar moieties attached to it. However, due to similar physico-chemical properties, isolation and identification of a large diversity of triterpenoid saponins remain challenging. This study demonstrates a methodology to screen saponins using hyphenated analytical platforms, GC-MS, LC-MS/MS, and LC-SPE-NMR/MS, in the example of two different phenotypes of the model plant Barbarea vulgaris (winter cress), glabrous (G) and pubescent (P) type that are known to differ by their insect resistance. The proposed methodology allows for detailed comparison of saponin profiles from intact plant extracts as well as saponin aglycone profiles from hydrolysed samples. Continuously measured 1D proton NMR data during LC separation along with mass spectrometry data revealed significant differences, including contents of saponins, types of aglycones and numbers of sugar moieties attached to the aglycone. A total of 49 peaks were tentatively identified as saponins from both plants; they are derived from eight types of aglycones and with 2–5 sugar moieties. Identification of two previously known insect-deterrent saponins, hederagenin cellobioside and oleanolic acid cellobioside, demonstrated the applicability of the methodology for relatively rapid screening of bioactive compounds.
ARTICLE | doi:10.20944/preprints202211.0284.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: microalgae; biomass; photosynthesis; mixotrophic; LC-MS/MS
Online: 15 November 2022 (09:54:52 CET)
NH4Cl is one of the nitrogen sources for microalgal cultivation. However, excessive amounts of NH4Cl affects microalgal physiology and biomass contents. In this study, the effects of ammonium on microalgal growth and TAG content in the green microalga (Chlamydomonas reinhardtii) was investigated. Microalgal growth and TAG content under photoautotrophic conditions were found to be unchanged with 17 mM of ammonium, while this compound interfered with microalgal growth and induced TAG content under mixotrophic conditions with acetate supplementation. This suggested that ammonium could induce TAG production when acetate occurred in microalgal cultivation. Further, the effects of two different concentrations of NH4Cl (17 mM and 60 mM) on the cells under mixotrophic conditions were investigated. The results showed that both concentrations reduced microalgal growth, but induced total lipid and TAG content, especially after a 4-day cultivation. The oxygen evolution and Fv/Fm ratio showed that both concentrations completely inhibited the oxygen evolution on Day 4. The 60 mM NH4Cl reduced the Fv/Fm ratio from 0.7 to 0.48 indicating that ammonium supplementation directly affects the microalgae photosynthesis performance. A total of 1782 proteins were successfully identified using proteomics analysis. Among them, there were nine overexpressed proteins and four proteins were underexpressed. Using the protein–ligand interaction analysis, nitrogen metabolism is involved under NH4Cl conditions. This information can provide biochemical knowledge for microalgae development for sustainable energy usage.
ARTICLE | doi:10.20944/preprints201901.0181.v1
Subject: Medicine And Pharmacology, Other Keywords: LC-MS/MS; Lipoid proteinosis; Carnitine; Acylcarnitine
Online: 17 January 2019 (13:05:31 CET)
Background and objectives: Lipoid proteinosis (LP) is an autosomal recessive transfer lysosomal storage disease, characterised by the accumulation of hyalin substance in the mucous membranes, skin, internal organs and brain, for which there is no biochemical diagnostic method. The aim of this study was to determine the carnitine and acylcarnitine metabolic profile with LC-MS/MS in LP patients and thereby examine the potential of this as a new biochemical method in the determination of biochemical markers in LP patients. Materials and Methods: In this study, 27 carnitine and acylcarnitine esters were measured with LC-MS/MS in serum samples taken from 14 healthy control subjects and 14 patients who presented at the Skin and Venereal Diseases Polyclinic and were diagnosed with LP as a result of clinical, radiological and histopathological examinations. Results: The results of the study showed that C0 (free carnitine) C3, C4, C4:DC, C5DC, C6, C8, C14:1, C14:2, C16 and C18 acylcarnitines were statistically significantly reduced in the LP patients (p<0.05, p<0.01). Conclusions: It was concluded that the application of carnitine profile screening, which is an inexpensive, rapid and reliable method, could make a contribution to the differential diagnosis as aa supporting laboratory test in individuals with suspected LP.
REVIEW | doi:10.20944/preprints201810.0327.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: LC-MS/MS, Rapid, Quantification, Oncology Drugs
Online: 15 October 2018 (16:57:44 CEST)
In the last decade, the tremendous improvement in the sensitivity and also affordability of Liquid Chromatography-tandem Mass Spectrometry (LC-MS/MS) have revolutionized its application in pharmaceutical analysis, resulting in wide-spread of employing LC-MS/MS for determining pharmaceutical compounds including anticancer drugs in pharmaceutical research and also industries. Currently, LC-MS/MS has been widely used to quantify small molecule oncology drugs in various biological matrices to support preclinical and clinical Pharmacokinetic studies in R & D of oncology drugs. This mini-review article will describe the state-of-the art LC-MS/MS and its application in rapid quantification of small molecule anticancer drugs. In addition, efforts have also been made in this review to address several key aspects in the development of rapid LC-MS/MS methods, including sample preparation, chromatographic separation and matrix effect evaluation.
ARTICLE | doi:10.20944/preprints201807.0043.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: nimbolide; LC-MS/MS; mouse; serum; pharmacokinetics
Online: 3 July 2018 (12:15:37 CEST)
A sensitive and robust liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the determination of nimbolide in mouse serum. Exemestane was used as the internal standard (IS). Here, we employed acetonitrile-based protein precipitation (PPT) for serum sample preparation, and performed chromatographic separation using an ODS Hypersil C18 column (100×2.1 mm, 5µm) with gradient elution (0.1% formic acid in water vs 100% acetonitrile). The run time was 6 min. Instrumental analysis was performed by electrospray ionization tandem mass spectrometry (ESI-MS/MS) in the multiple-reaction monitoring (MRM) under positive mode. A good linear calibration was achieved in the 5–1000 ng/ml range. The intra- and inter-day precisions for nimbolide were ≤ 12.6% and ≤ 13.9 % respectively. Intra-day accuracy ranged from 96.9% – 109.3% while inter-day accuracy ranged from 94.3% – 110.2%. The matrix effect of nimbolide, detected but consistent at low and high concentrations, do not affect linearity of standard curve. In conclusion, we have developed and validated a sensitive analytical method for determination of a novel natural compound nimbolide in mouse serum and it has been successfully applied to our preclinical study in investigating the pharmacokinetic properties of nimbolide, which could greatly facilitate the preclinical development of the promising lead compound for anticancer therapy.
ARTICLE | doi:10.20944/preprints202308.1710.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: β-agonists; LC-MS/MS; automated SPME; pork
Online: 24 August 2023 (04:45:13 CEST)
This study presents an innovative analytical method for the detection and quantification of 14 β-agonists in pork using liquid chromatography-tandem mass spectrometry (LC-MS/MS). The method involves the use of a solid phase microextraction (SPME) probe, consisting of a wooden tip coated with polyacrylonitrile (PAN) and molecularly imprinted polymer (MIP). This probe has been integrated into an automated extraction device, designed in our laboratory to extract the target analytes prior to LC-MS/MS analysis. Compared to the traditional solid-phase extraction (SPE) procedure, the proposed approach significantly reduces the costs related to adsorbent ma-terial and solvent consumption, and shortens purification time, thereby reducing both the tech-nical workload and associated expenses. The methodology has been carefully validated in ac-cordance with the National Standard of the People's Republic of China (GB/T 22286-2008), evalu-ating key parameters including the limit of detection (LOD), limit of quantification (LOQ), matrix effects, linearity, and both intra-day and inter-day precision. The average recovery rates for all β-agonists were observed to lie between 71.6% and 82.2%, with relative standard deviations (RSDs) consistently below 15% for both types of precision. The LOD and LOQ values were found to range from 0.09 to 0.39 μg/kg and 0.27 to 0.99 μg/kg, respectively. In terms of accurate detection of positive samples, the developed method demonstrated a closer approximation to the true value of the sample compared to the National Standard method GB/T 31658.22-2022. Overall, the proposed method exhibits substantial promise for the routine assessment of β-agonists in pork and presents a practical alternative for compliance monitoring in regulatory settings.
COMMUNICATION | doi:10.20944/preprints202305.0506.v1
Subject: Environmental And Earth Sciences, Environmental Science Keywords: AIQS-DB; GC/MS; LC/MS; simultaneous analysis
Online: 8 May 2023 (10:11:22 CEST)
This article summarizes studies using the AIQS-DB method to analyze various types of samples for different purposes. This is a method developed to simultaneously analyze nearly 1500 compounds and is widely used worldwide. The method is highly effective for environmental samples such as water, soil, sediment, and air. Recognizing its potential, this article aims to promote the further application and development of AIQS-DB in research related to food analysis and source tracing. Furthermore, if a suitable dataset can be constructed, it could help research quickly and cost-effectively discover the new bioactive compounds from plant medicine.
ARTICLE | doi:10.20944/preprints202008.0222.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Erlotinib; POLA2; DARTS LC-MS/MS; Resistance; NSCLC
Online: 9 August 2020 (21:26:35 CEST)
Erlotinib inhibits epithelial growth factor receptor (EGFR) kinase activity and is used to treat non-small cell lung cancer (NSCLC). Despite its high efficacy, recurrence can occur in patients who become resistant to the drug. To address the underlying mechanism of Erlotinib resistance, we investigated additional mechanisms related to mode-of-drug-action, by multiple protein-binding interactions, besides EGFR by using drug affinity responsive target stability (DARTS) and liquid chromatography-mass spectrometry (LC-MS/MS) methods with non-labeled Erlotinib. DNA polymerase alpha subunit B (POLA2) was identified as a new Erlotinib binding protein that was validated by the DARTS platform, complemented with cellular thermal shift assays. Genetic knock-down of POLA2 promoted the anti-proliferative effect of the drug in the Erlotinib-resistant cell line H1299 with high POLA2 expression, whereas overexpression of POLA2 restored anti-proliferative effects in the Erlotinib-sensitive cell line HCC827 with low POLA2 expression. Importantly, POLA2 expression levels in four NSCLC cell lines were positively correlated with anti-proliferative Erlotinib efficacy, verified by bio-statistical analysis (Pearson correlation coefficient, R=0.9886). These results suggest that POLA2 is a novel complementary target protein of Erlotinib, and could clinically provide validity as a surrogate marker for drug resistance in patients with NSCLC.
ARTICLE | doi:10.20944/preprints201704.0080.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: metabolomics; LC-MS; GC-MS; plasma; brain tissue
Online: 14 April 2017 (04:41:05 CEST)
Metabolomic analysis of biological fluids and tissues has become an increasingly routine tool in the biological toolbox. However, challenges remain to be overcome, including developing strategies to maximise coverage of the metabolome without requiring large sample volumes. Here we describe a multimodal strategy that combines data using both LC-MS and GC-MS from a unique vial with a sample of plasma (20µl) or a sample of brain tissue (3mg). Using a split phase extraction the non-aqueous phase was analyzed by reversed phase (RP) LC-MS, whilst the aqueous phase was analyzed using hydrophilic liquid interaction chromatography (HILIC)LC-MS, with both phases also analysed using GC-MS after derivatization of the extract. Analytical performance was assessed in 7 rat cerebellum samples and a pilot study of 40 plasma samples (20 vs. 20: AD vs. healthy controls). The method, which uses four hours of instrument time, measured 20,707 metabolite features in brain samples and 17,266 in plasma samples, from those 44.1% features displayed CV’s below 15% and 75.2% below 30%. The method has potential to resolve subtle biological differences and to correlate metabolite composition directly to clinical outcomes including MMSE, age and ADCS-ADL. This method can acquire in the order of 20K metabolic features when low volumes are available.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Bisphenol A; metabolites; meat and meat products; LC-MS/MS; GC-MS/MS
Online: 11 March 2021 (14:55:50 CET)
BPA is a commonly used compound in many industries and has versatile applications in polycarbonate plastics and epoxy resins production. BPA is classified as endocrine-disrupting chemical which can hamper fetal development during pregnancy and may have long term negative health outcomes in humans. Dietary sources, main route of BPA exposure, can be contaminated by the migration of BPA into food during processing. The global regulatory framework for using this compound in food contact materials is currently not harmonized. This review aims to outline, survey, and critically evaluate BPA contamination in meat products, including level of BPA and/or metabolites present, exposure route, and recent advancements in the analytical procedures of these compounds from meat and meat products. The contribution of meat and meat products to the total dietary exposure of BPA ranges between 10 and 50% depending on the country and exposure scenario considered. From can lining materials of meat products, BPA migrates towards the solid phase resulting higher BPA concentration in solid phase than the liquid phase of the same can. The analytical procedure is comprised of meat sample pre-treatment, followed by cleaning with SPE, and chromatographic analysis. Considering several potential sources of BPA in industrial and home culinary practices, BPA can also accumulate in non-canned or raw meat products. Very few scientific studies have been conducted to identify the amount in raw meat products. Similarly, analysis of metabolites and identification of the origin of BPA contamination in meat products is still a challenge to overcome.
ARTICLE | doi:10.20944/preprints202308.1182.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: table olives; ochratoxin A; aflatoxins; ELISA; LC-MS/MS
Online: 16 August 2023 (10:31:46 CEST)
This study is aimed to point out the possible application of the Enzyme-Linked ImmunoSorbent Assay (ELISA) test on table olives. Because olives, like many other foods, are not free from mycotoxin contamination, the main focus of this work was assessing the presence or absence of aflatoxins and ochratoxin A. The work was carried out in two phases. In the first phase, tests were carried out on commercial olives to assess the efficacy of the method and the kit (Veratox® 'Neogen' and AgraQuant® 'Romer Labs') by comparing them with the Liquid Chromatography coupled to a mass-mass spectrometer (LC-MS/MS); in order to understand if there were any interferences in antigen-antibody recognition; subsequently, mycotoxins were inoculated on the same samples with a known quantity, in order to assess the concentrations obtained and compare them to the expected ones. The second step involved modifying the method, so to improve the recovery of inoculated mycotoxins in the samples under study. Afterwards we evaluated the presence of mycotoxins in table olives supplied in the project. The results showed the effectiveness of the ELISA test, especially in the mycotoxin recovery phase. Indeed, after the modification of the mycotoxin extraction method, recoveries increased from 55% to over 70% for aflatoxins, and from 40% to over 55% for ochratoxin A. When analysing the samples provided by the above-mentioned company, the results showed some false positives, in particular in relation to ochratoxin A ’s analysis, mainly related to the first sample submission. Taking this into account, the ELISA test can be considered as an initial screening method applicable as a control programme for the evaluation of mycotoxins in olives which helps by saving time and costs. It should always be kept in mind that, if positive values should emerge, the LC-MS/MS analysis should be carried out.
ARTICLE | doi:10.20944/preprints202012.0453.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Actinidia arguta; leaf; bioactivity; antioxidant activity; LC-MS/MS
Online: 18 December 2020 (11:14:24 CET)
Actinidia arguta (Sieb. et Zucc.) Planch. ex Miq. is abundant of vitamin C and bioactive compounds with high antioxidant activities. In this study, eight wild A. arguta accessions from different areas in Northeast China were collected. Some bioactive compounds were examined on the different tissues of different germplasms including four kinds of leaves, petioles and fruits. The method of UPLC-MS was used to detect the flavonoid compounds. The results showed that some bioactive compounds including vitamin C, soluble sugar, free amino acid, total phenolics and flavonoids content showed significant differences between six tissues of A. arguta accessions and showed significant variability with maturity. In eight accessions, the highest vitamin C content was found in young apical leaves of ‘CBS-6’ (7.47 mg/g fresh weight), and the highest soluble sugar content was in fruits of ‘CJ-1’ (196.52 mg/g fresh weight) and the highest total phenolic content and total flavonoids content were in young apical leaves of ‘CBS-11’ (3.48 mg/g fresh weight) and of ‘CBS-3’ (2.00 mg/g fresh weight), respectively. Ten flavonoid compounds including kaempferol, isorhamnetin and quercetin were detected in leaves, petioles and fruits. The total content of flavonoids were highest in young apical leaves (10219.84 µg·g-1) and the lowest in fruits (78.75 µg·g-1). Based on the comparison of the contents of several bioactive compounds, the two accessions ‘CJ-1’ and ‘CBS-8’ had relatively outstanding performance, and in the comprehensive evaluation of the antioxidant activity among different tissues, the young leaves had the strongest antioxidant activity. These results highlighted the antioxidant potentialities of A. arguta leaves as a major source of phenolics and vitamin C as well as flavonoids. It provided a theoretical basis for the utilization of leaves of A. arguta.
ARTICLE | doi:10.20944/preprints201808.0314.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: MELK inhibitor; OTS167; LC-MS/MS; Pharmacokinetics, mouse serum
Online: 17 August 2018 (15:15:12 CEST)
A novel, rapid and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the evaluation of OTS167 pharmacokinetics in mouse serum. SN-38 was optimized to be selected as the internal standard. Chromatographic separation was performed on a BDS Hypersil C18 column (100 x 2.1 mm, 5 µm) using gradient elution with mobile phase solvent A as water containing 0.1% formic acid and solvent B as acetonitrile containing 0.1% formic acid. The analysis was carried out using multiple reaction monitoring (MRM) with a triple-quadrupole mass spectrometer operated in the positive electrospray ionization mode. Mass transitions of 487.2 > 348.0 and 393.2 > 349.2 were monitored for OTS167 and SN-38 respectively. The standard calibration curve demonstrated high linearity at a range of 5-1000 ng/mL, with a coefficient of determination (r2) ≥ 0.996. The accuracy for OTS167 ranged from 92.3% to 102.2% and the precision was ≤ 12.7%. Recovery was consistent at about 83% to 89%. No significant matrix effect was observed. This method was successfully applied to monitor the pharmacokinetic profiles in mice over 24 h after ingestion of 5 mg/kg of OTS167. Maximum serum concentrations (3197 ng/mL) of OTS167 was observed at 1.67 hour after OTS167 ingestion via garage at 5 mg/kg and area under the curve (AUC) was 28579 h*ng/mL, suggesting that OTS167 can be quickly absorbed after oral administration.
ARTICLE | doi:10.20944/preprints202208.0202.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: blueberries; bile acids; dietary supplements; polyphenols; LC-MS/MS profiling
Online: 10 August 2022 (11:57:59 CEST)
Cholesterol-derived bile acids (BAs) affect numerous physiological functions such as glucose homeostasis, lipid metabolism and absorption, intestinal inflammation and immunity, as well as intestinal microbiota diversity. Diet influences the composition of the BA pool. The present study analyzes the impact of a dietary supplementation with a freeze-dried blueberry powder (BBP) on the fecal BA pool composition. The diet of 11 men and 13 women at risk for metabolic syndrome was supplemented with 50g/day of BBP for 8 weeks, and feces were harvested before (pre) and after (post) BBP consumption. BAs were profiled using liquid chromatography coupled to tandem mass spectrometry. No significant changes in total BAs were detected when comparing pre- vs post-BBP consumption samples. However, post-BBP consumption samples exhibited significant accumulations of glycine-conjugated BAs (p=0.04), glycochenodeoxycholic (p=0.01) and glycoursodeoxycholic (p=0.01) acids, as well as a significant reduction (p=0.03) of the secondary BA levels, when compared to pre-BBP feces (p=0.03). In conclusion, the fecal bileacidome is significantly altered after the consumption of BBP for 8 weeks. While additional studies are needed to fully understand the underlying mechanisms and physiological implications of these changes, our data suggest that the consumption of blueberries can modulate toxic BAs elimination.
ARTICLE | doi:10.20944/preprints202201.0092.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Synthetic cannabinoids; LC-MS/MS; Simultaneous determination; Matrix effect; Urine
Online: 6 January 2022 (14:10:17 CET)
Synthetic cannabinoids are a series of synthetic substances that mimic the effects of natural cannabinoids and produce a much stronger toxicity than natural cannabinoids, which have become the most abused family of new psychoactive substances. A solid-phase extractive-liquid chromatography-triple quadrupole/linear ion trap mass spectrometry method was developed to determine 11 synthetic cannabinoids in rat urine. The factors affecting recovery were optimized, and Oasis HLB was selected to extract synthetic cannabinoids simultaneously. The results showed that the linear correlation coefficients of the synthetic cannabinoids ranged from 0.993 to 0.999, and the limit of quantitation ranged from 0.01 to 0.1 ng/mL, and the spiked recoveries ranged from 69.90% to 118.39%. This method has the advantages of good purification ability, simple operation, and good reproducibility, and can be used for the high sensitivity analysis of various synthetic cannabinoids in urine.
ARTICLE | doi:10.20944/preprints202103.0446.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: acrylamide; coffee; partial least square regression; NMR; LC-MS/MS
Online: 17 March 2021 (14:48:40 CET)
Acrylamide is probably carcinogenic to humans (International Agency for Research on Cancer, group 2A) with major occurrence in heated, mainly carbohydrate-rich foods. For roasted coffee, a European Union benchmark level of 400 µg/kg acrylamide is of importance. Regularly, the acrylamide contents are controlled using liquid chromatography combined with tandem mass spectrometry (LC-MS/MS). This reference method is reliable and precise but laborious because of the necessary sample clean-up procedure and instrument requirements. This research investigates the possibility of predicting the acrylamide content from proton nuclear magnetic resonance (NMR) spectra that are already recorded for other purposes of coffee control. In the NMR spectrum acrylamide is not directly quantifiable, so that the aim was to establish a correlation between the reference value and the corresponding NMR spectrum by means of a partial least squares (PLS) regression. Therefore, 40 commercially available coffee samples with already available LC-MS/MS data and NMR spectra were used as calibration data. To test the accuracy and robustness of the model and its limitations, 50 coffee samples with extreme roasting degrees and blends were additionally prepared as test set. The PLS model shows an applicability for the varieties C. arabica and C. canephora, which were medium to very dark roasted using drum or infrared roasters. The root mean square error of prediction (RMSEP) is 79 µg/kg acrylamide (n=32). The PLS model is judged as suitable to predict the acrylamide values of commercially available coffee samples. On the other hand, very light roasts containing more than 1000 µg/kg acrylamide are currently not suitable for PLS prediction.
ARTICLE | doi:10.20944/preprints202309.2013.v1
Subject: Biology And Life Sciences, Neuroscience And Neurology Keywords: Drosophila melanogaster; cocaine; methamphetamine; neurotransmitter concentration; locomotor sensitization; LC-MS/MS
Online: 29 September 2023 (04:30:31 CEST)
Due to similarities in genetics, cellular response, and behavior, Drosophila is used as a model organism in addiction research. A well described behavioral response examined in flies is the induced increase in locomotor activity after a single dose of volatilized cocaine (vCOC) and volatilized methamphetamine (vMETH) known as sensitivity, and the escalation of the locomotor response after the repeated dose, known as the locomotor sensitization. However, knowledge about how vCOC and vMETH affect different neurotransmitter systems over time is scarce. We used LC-MS/MS to systematically examine changes in the concentration of neurotransmitters, metabolites and non-metabolized COC and METH in the whole head homogenates of male flies one to seven hours after single and double vCOC or vMETH administrations. vMETH leads to complex changes in the levels of examined substances over time, while vCOC strongly and briefly increases concentrations of dopamine, tyramine and octopamine followed by a delayed degradation into N-acetyl dopamine and N-acetyl tyramine. The first exposure to psychostimulants leads to significant and dynamic changes in the concentrations relative to the second administration when they are more stable over several hours. Further investigations are needed to understand neurochemical and molecular changes post-psychostimulant administration.
ARTICLE | doi:10.20944/preprints202306.0847.v1
Subject: Medicine And Pharmacology, Pharmacy Keywords: S-Allyl Cysteine; Oral Bioavailability; PLGA NPs; LC–MS/MS; Pharmacokinetics
Online: 12 June 2023 (14:09:39 CEST)
A newly UHPLC-MS/MS method development and validation for S-Allyl Cysteine was used to evaluate the comparative pharmacokinetic parameters. SC PLGA NPs were developed by the emulsion solvent evaporation method. SC PLGA NPs showed their drug loading and encapsulation efficiency i.e. 5.13±0.10% and 82.36±4.01%, respectively. SC PLGA NPs showed a spherical morphology on an average size (134.8±4.61nm), PDI: 0.277±0.004, and −25.3±1.03mV zeta-potential is suitable for oral delivery. Development and validation of the UHPLC-MS/MS bioanalytical method were performed successfully for PK-parameters examinations with 1.219-minutes RT, MS (162.00/73.10), and a total run-time was 2.0-minutes. 1.0–1000.0ng/mL was a linear-range with inter & intra-day accuracy (92.55–99.40%) followed by precision (1.88–4.23%). SC PLGA NPs oral bioavailability was significantly higher (**p<0.01) as compared to SC-S treated groups (iv & oral). We found that the antimicrobial activity of SC PLGA NPs was more effective than pure S-Allyl-L-Cysteine with significant results (p<0.01) as compared to SC-S. SC PLGA NPs showed fitted physicochemical and enhanced antimicrobial properties which can be helpful for oral administration. On the basis of our observations, SC PLGA NPs suggested the highest potential for the improvement of oral bioavailability with a sustained and controlled release of S-Allyl-L-Cysteine delivery.
ARTICLE | doi:10.20944/preprints202307.0034.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: bisphenol analogues; canned foods; food matrices; QuEChERS; GC-MS; LC-MS/MS; endocrine disruptors
Online: 3 July 2023 (09:35:01 CEST)
Exposure to bisphenol analogues can occur in several ways throughout the food production chain with their presence at higher concentrations representing a risk to human health. This study aimed to develop effective analytical methods to simultaneously quantify BPA and fifteen bisphenol analogues (i.e., bisphenol AF, bisphenol AP, bisphenol B, bisphenol BP, bisphenol C, bisphenol E, bisphenol F, bisphenol G, bisphenol M, bisphenol P, bisphenol PH, bisphenol S, bisphenol Z, bisphenol TMC and tetramethyl bisphenol F) present in canned foods and beverages. Samples of foods and beverages available in the Swiss and EU markets (n = 22) including canned pineapples, ravioli and beer were prepared and analyzed using QuEChERS GC-MS. The quantification method was compared to a QuEChERS LC-MS/MS analysis. This allowed for the selective and efficient quantitative simultaneous analysis of bisphenol analogues. Quantities of these analogues were present in 20 of the 22 samples tested with the most frequent analytes at higher concentrations; BPA and BPS being discovered in 78% and 48% of cases respectively. The study demonstrates the robustness of QuEChERS GC-MS for determining low quantities of bisphenol analogues in canned foods. However, further studies are necessary to achieve full knowledge of the extent of bisphenol contamination in the food production chain and its associated toxicity.
ARTICLE | doi:10.20944/preprints202309.1442.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Macroalgae; Fatty acid; trimethylaminoethyl derivatives; Solid phase Extraction; LC-ESI-MS/MS
Online: 21 September 2023 (05:17:47 CEST)
The extraction method for simultaneously analyzing fatty acids (Myristic acid, cis-Palmitvaccenic acid, Palmitic acid, Palmitic-9,9-d2 acid, Oleic acid, Stearic acid and Stearic-2,2-d2 acid) related to biodiesel fuel in large algae was developed. The introduction of trimethylaminoethyl (TMAE) derivatives into the hydroxyl group (-OH) functional group of the analyte was able to improve ionization and obtain high sensitivity. Liquid Chromatography (LC) was used to investigate the optimal mobile phase composition and flow rate for the separation of five derived fatty acids. In this study, a solid phase extraction (SPE) column was introduced for efficient extraction of fatty acids, and the optimal conditions for SPE were set by comparing the recovery rate according to the solvent for each step (loading, washing, and elution) of SPE from macroalgae.
ARTICLE | doi:10.20944/preprints202308.0527.v1
Subject: Biology And Life Sciences, Animal Science, Veterinary Science And Zoology Keywords: Analytical method; antimicrobials; coccidiostats; LC/MS/MS; multi-residue analysis; broiler litter
Online: 7 August 2023 (11:54:37 CEST)
Anti-microbial drugs and coccidiostat compounds are commonly used in poultry farming. These compounds are subsequently excreted and released into the environment via broiler litter (BL) and can re-enter the food chain as fertilizer and/or animal feed. Residues of such drugs can encourage the appearance of antibiotic-resistant bacteria (ARB), as well as toxicity, when found in animal feed. The aim of this study was to develop a multi-residue analytic method for assessing 30 an-ti-microbial drugs and coccidiostats associated with BL and investigate the effects of stacking treatment on anti-microbial and coccidiostat residue degradation in BL used for ruminant feed at the lab-scale. Today, most analytical methods used to identify and quantitate these drug residues are traditional, and may be specific to some antimicrobials. All call for lengthy sample preparation and may present limitations in assessing broiler litter. Such conventional mul-ti-anti-microbial/coccidiostat residue detection assays employ liquid-liquid extraction (LLE) and solid phase extraction (SPE) for sample purification. In our research, LLE and SPE were replaced by Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) clean-up steps for 30 an-ti-microbials and coccidiostats used in broiler farming and detection by liquid chromatography mass spectrometry (LC/MS/ MS). Using this method, recoveries were 70-120%, with the exception of norfloxacin and narasin, which showed recoveries of 67 and 68%, respectively. This analytical meth-od results show that eight samples were not detected in 42 samples, while in 34 samples, one or more drugs were present. Eighteen anti-microbial and coccidiostat residues were detected dur-ing one year sample collaction. The most frequently detected residues were narasin, nicarbazin, monensin, robenidine, oxytetracycline, chlortetracycline, norfloxacin and sulfachloropyridazine, seen at levels from 0.4 to 8.9 mg•kg-1 (ppm). Nineteen anti-microbials and one coccidiostat were degraded to 95% by the stacking treatment. However, tilmicosin and eight coccidiostats persisted in litter (26-100%). The use of antimicrobials and coccidiostats in animal farming is of paramount concern with respect to human, animal and environmental contamination issues and as a source of resistant pathogenic bacteria. Still, most farmers use BL as ruminant feed and fertilizer without processing. Even though the effects of the stacking treatments on degradation of antimicrobials were significantly high, the degradation of coccidiostats and tilmicosin was limited. Clearly, BL should be treated and supervised before use as feed supplement or for land application. Hence, the present method, designed to support these goals, was optimized in terms of sensitivity and se-lectivity for the analytes addressed.
ARTICLE | doi:10.20944/preprints202308.0522.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: lung cancer; NSCLC; lipidomic analysis; saliva; plasma; feces; LC-ESI-MS/MS
Online: 7 August 2023 (11:49:40 CEST)
A comprehensive lipid profile was analyzed in patients with non-small cell lung cancer (NSCLC) using nanoflow ultrahigh-performance liquid chromatography-electrospray ionization-tandem mass spectrometry. The study investigated 297, 202, and 166 lipids in saliva, plasma, and fecal samples, respectively, comparing NSCLC patients to healthy controls. Lipids with significant changes (>2-fold, p<0.05) were further analyzed in each sample type. Both saliva and plasma exhibited similar lipid alteration patterns in NSCLC, but saliva showed more pronounced changes and fecal lipids had weak correlation with those of saliva and plasma. Total triglycerides (TGs) increased (>2–3 folds) in plasma and saliva but decreased in fecal samples. Three specific TGs (50:2, 52:5, and 54:6) were significantly increased in NSCLC across all sample types. A common ceramide species (d18:1/24:0) decreased in both plasma and saliva but increased in fecal samples. Additionally, phosphatidylinositol 38:4 decreased by approximately 2-fold in plasma and saliva. Phosphatidylserine 36:1 was selectively detected in saliva and showed a subsequent decrease, making it a potential biomarker for predicting lung cancer. The study identifies 27 salivary, 10 plasma, and 16 fecal lipids as candidate markers for NSCLC by statistical evaluations. Moreover, it highlights the potential of saliva in understanding changes in lipid metabolism associated with NSCLC.
ARTICLE | doi:10.20944/preprints202108.0100.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: PF-543; ceramide; SPHK; SPT; ceramide synthases; sphingolipid; metabolism; LC-MS/MS.
Online: 4 August 2021 (08:32:59 CEST)
Sphingosine-1-phosphate (S1P) synthesized by sphingosine kinase (SPHK) is a signaling molecule, involved in cell proliferation, growth, differentiation, and survival. Indeed, a sharp increase of S1P was linked to the pathological outcome with inflammation, cancer metastasis or angiogenesis etc. In this regard, the SPHK/S1P axis regulation has been a specific issue in anticancer strategy to turn accumulated sphingosine (SPN) into cytotoxic ceramides (Cers). For these purposes, there have been numerous chemicals synthesized for SPHK inhibition. In this study, we investigated the comparative efficiency of dansylated PF-543 (DPF-543) on the Cers synthesis along with PF-543. DPF-543 deserved attention in strong cytotoxicity, due to the cytotoxic Cers accumulation by ceramide synthase (CerSs). DPF-543 exhibited dual actions on Cers synthesis by enhance the serine palmitoyltransferase (SPT) activity, and by inhibiting SPHKs which eventually induced an unusual environment of the high amount of 3-ketosphinganine and sphinganine (SPA). SPA in turn was consumed to synthesize Cers via de novo pathway. Interestingly, PF-543 increased only the SPN level, but not for SPA. In addition, DPF-543 mildly activates acid sphingomyelinase (aSMase) that contributes a partial increase on Cers. Collectively, a dansyl-modified DPF-543 relatively en-hanced Cers accumulation via de novo pathway which was not observed in PF-543. Our results demonstrated that the structural modification on SPHK inhibitors is still an attractive anticancer strategy by regulating sphingolipid metabolism.
ARTICLE | doi:10.20944/preprints202304.0062.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Exosomes; lymphoma; LC-MS; pro-tumoral macrophages; cytokines
Online: 5 April 2023 (12:14:37 CEST)
Macrophages are the key effector cells of innate immunity which show two polarized states: M1, classically activated and M2, alternatively activated. Tumor-associated macrophages (TAMs) which usually show M2 polarization, are immunosuppressive cells that enhance tumor metastasis and invasion. Also, enrichment of TAMs is known to be closely associated with poor prognosis of cancer patients. Therefore, TAMs are considered to be promising targets for immunotherapy. Importantly, tumor-derived exosomes emerged as a crucial player in immune regulation which can remodel the tumor microenvironment towards immunosuppressive state. Of note, few studies have shown that exosomes could induce polarization of macrophages towards M2 type in tumor condition, while others showed activation of M1 or mixed phenotype. Considering the role of TAMs in cancer, there is an urgent need to decipher the exosome-mediated cross-talk between tumor cells and macrophages.For this, we used murine model of Dalton’s lymphoma (DL), wherein, firstly, we evaluated increased exosome burden by assessing exosome level in serum as well as in various tissues of tumor-bearing host. Next, proteomic profiling of lymphoma-derived exosomes was done which revealed the presence of immunomodulatory proteins. Of note, these proteins were known to alter the macrophage polarization. In order to assess the effect of these exosomes on macrophages, we performed in vitro study using RAW264.7 cells. In vitro study revealed that frequent uptake of exosomes mediated a morphological change in macrophages which reduced their phagocytic activity. In parallel, exosomes increased reactive oxygen species (ROS) level and inhibited LPS-induced nitric oxide (NO) level in macrophages. Also, exosomes upregulated the expression of arginase-1 (an M2 marker) in macrophages but decreased the LPS-induced nitric oxide synthase 2 (NOS2) (an M1 marker) expression. Moreover, we observed a pro-tumoral cytokine profile in macrophages incubated with exosomes. Our study suggests that exosome load increases in lymphoma-bearing hosts systemically. Importantly, lymphoma-derived exosomes mediate the activation of macrophages towards pro-tumoral M2 type. Our results give an insight into the exosome-mediated tumor and immune cell cross-talk which could serve as an important prospect for targeting in cancer immunotherapy.
Subject: Biology And Life Sciences, Plant Sciences Keywords: untargeted approach; metabolites; drought stress; mulberry, LC-MS
Online: 6 July 2021 (17:23:32 CEST)
Mulberry is an economically significant crop for the sericulture industry worldwide. Stresses such as drought exposure have a significant influence on plant survival. Metabolome directly reflects plant physiological status; thus, a way to assess this impact is to perform a global metabolomic analysis. This study investigated the effect of drought stress on mulberry Yu-711 metabolic balance using a liquid chromatography-mass spectrometry (LC-MS) based on an untargeted metabolomic approach. For this objective, Yu-711 leaves were subjected to two weeks of drought stress treatment and control without drought stress. Multivariate and univariate statistical analyses highlighted numerous differentially-accumulated metabolic elements as a function of time and treatment. Drought stress led to a more differentiated metabolites response than the control. We found that the levels of total lipids and galactolipids, and phospholipids (PC, PA, PE) were significantly altered, producing 48% of the total differentially expressed metabolites. Fatty acyls were the most abundant lipids expressed and decreased considerably by 73.6%. Prenol lipids class of lipids increased in drought leaves. Other classes of metabolites, including polyphenols( flavonoids and cinnamic acid), organic acid (amino acids), carbohydrates, benzenoids, and organoheterocyclic, all had a dynamic trend in response to the drought stress. However, their levels under drought stress generally decreased significantly compared to the control. These results provide an overview of the metabolic profile of the mulberry plant through differentially-accumulated compounds and provide a better understanding of global plant metabolic changes in defense mechanisms.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: high-intensity training; LC-MS; urine; water polo
Online: 2 March 2021 (09:37:59 CET)
Objective: To study the changes in urine metabolism in female water polo players before and after high-intensity training by using ultra-high performance liquid chromatography-mass spectrometry, and to explore the biometabolic characteristics of urine after training and competition. Methods: Twelve young female water polo players (except goalkeepers) from Shanxi Province were selected. A 4-week formal training was started after one week of acclimatization according to experimental requirements. Urine samples (5 ml) were collected before formal training, early morning after 4 weeks of training, and immediately after 4 weeks of training matches, and labeled as T1, T2, and T3, respectively. The samples were tested by LC-MS after pre-treatment. XCMS, SIMCA-P 14.1, and SPSS16.0 were used to process the data and identify differential metabolites. Results: On comparing the immediate post-competition period with the pre-training period (T3 vs T1), 24 differential metabolites involved in 16 metabolic pathways were identified, among which niacin and niacinamide metabolism and purine metabolism were potential post-competition urinary metabolic pathways in the untrained state of the athletes. On comparing the immediate post-competition period with the post-training period (T3 vs T2), 10 metabolites involved in 3 metabolic pathways were identified, among which niacin and niacinamide metabolism was a potential target urinary metabolic pathway for the athletes after training. Niacinamide, 1-methylnicotinamide, 2-pyridone, L-Gln, AMP, and Hx were involved in two metabolic pathways before and after the training. Conclusion: Differential changes in urine after water polo games are due changes in the metabolic pathways of niacin and niacinamide.
ARTICLE | doi:10.20944/preprints202203.0012.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: aquaculture; fish; salmon; feces; deconjugation; hydrolysis; extraction; chromatography; mass spectrometry; LC-MS/MS
Online: 1 March 2022 (09:36:18 CET)
The aquaculture industry has become a sustainable provider of food to humans. Remaining challenges include disease issues, as well as ethical concerns for discomfort and stress among farmed fish. There is a need for reliable biomarkers to monitor welfare in fish, and the stress hormone cortisol has been suggested as a good candidate. This study presents a novel method for measurement of cortisol in fish feces based on enzymatic hydrolysis, liquid-liquid extraction, derivatization, and finally instrumental analysis by liquid chromatography coupled with tandem mass spectrometry. Hydrolysis and extraction conditions were optimized. Cortisol appeared to be mostly conjugated to sulfate and less conjugated to glucuronic acid in the studied samples of feces from farmed Atlantic salmon. The method was suitable for quantification of cortisol after enzymatic deconjugation by either combined glucuronidase and sulfatase activity, or by glucuronidase activity alone. The limit of detection was 0.15 ng/g and the limit of quantification was 0.34 ng/g, and the method was linear (R2>0.997) up to 380 ng/g, for measurement of cortisol in wet feces. Method repeatability and intermediate precision were acceptable, both with a CV of 11%. Stress level was high in fish released into seawater, and significantly reduced after eight days.
Subject: Biology And Life Sciences, Food Science And Technology Keywords: broiler; feed additives; LC–MS/MS; meat legislation; meat safety; poultry meat; veterinary drugs
Online: 22 September 2021 (12:13:55 CEST)
Brazil chicken production is around 13 million tons and about a third is exported to over 150 countries, placing Brazil as the world largest chicken meat producer, and therefore it is crucial to follow the legislation of all importer markets. This study conducted a survey by chance in 45 meat industries able to export. Therefore, 2580 chicken meat samples were collected and submitted to 11 analyte extraction and chromatographic verification of compliance in an accredited laboratory. Ten chemical residues (amoxicillin, bacitracin, colistin, dinitolmide + zoalene, spectinomycin, roxarsone, tiamulin, tylosin, trenbolone acetate and virginiamycin) were investigated in chicken meat and one (halofuginone hydrobromide) in chicken liver. The results showed that no compound exceeded the maximum residue limits established by seven legislations. All residue concentrations found were below the method quantification limit, thereby confirming the capability of Brazilian chicken meat industries in complying to foreign markets.
Subject: Chemistry And Materials Science, Food Chemistry Keywords: tree peony flowers; sugars and organic acids; amino acids; polyphenols; GC-MS; LC-MS
Online: 20 March 2019 (15:09:50 CET)
Tree peony flowers are traditional ornamental and medicinal materials in China. In this study, 23 tree peony flowers at a broad color spectrum were analyzed. Gas chromatography-mass spectrometer (GC-MS) revealed that tree peony flowers are rich in sugars and organic acids. Up to 18 amino acids were identified by liquid chromatography-mass spectrometer (LC-MS), including all essential amino acids, except for methionine. The majority of amino acids were significant positively correlated with each other and were significant negatively correlated with glucose, fructose and galactose. A total of 11 polyphenols were identified in these tree fresh peony flowers by LC-MS. There was a high consistency in grouping peony flowers by using sugars and organic acids and amino acids, which differed from that based on color components and polyphenols. Tree peony flowers are also rich in K, Ca, Mg and Fe. In together, peony flowers can be a good resource of health-promoting compounds.
BRIEF REPORT | doi:10.20944/preprints202307.0613.v1
Subject: Biology And Life Sciences, Virology Keywords: COVID19; SARS-CoV-2; Variants of Concern; Diagnosis; LC-MS/MS; Mass-Spectrometry; Spike; Nucleocapsid
Online: 11 July 2023 (03:01:19 CEST)
The spread of SARS-CoV-2 variants of concern (VOCs), is of great importance to the whole community, since their genetic changes may increase transmissibility, disease severity and reduce effectiveness of vaccines. Moreover, these changes may lead to failure of diagnostic measures, thus variant-specific diagnostic methods are essential. To date, genetic sequencing is the gold standard method to discriminate between variants, however it is time consuming (several days) and expensive. Therefore, the development of rapid diagnostic methods for SARS-CoV-2 in accordance with its genetic modification is of great importance. In this study, we introduce a Mass-Spectrometry (MS)-based methodology for the diagnosis of SARS-CoV-2 in clinical specimens, a methodology which enables universal identification, alongside with variant-specific discrimination. The universal identification of SARS-CoV-2 is based on conserved markers shared by all variants, while the identification of the specific variant relies on variant-specific markers. Determining a specific set of peptides for a given variant consists of a multistep procedure, starting with in-silico search for variant-specific tryptic peptides, followed by tryptic digest of a cell-cultured SARS-CoV-2 variant and identification of these markers by HR-LC-MS/MS analysis. As a proof of concept, this approach was demonstrated for four representative VOCs, in comparison with the wild-type Wuhan reference strain. For each variant, at least two unique markers, derived mainly from the spike (S) and nucleocapsid (N) viral proteins, were identified. This methodology is specific, rapid, easy to perform and inexpensive, therefore can be applied as a general diagnostic tool of pathogenic variants.
ARTICLE | doi:10.20944/preprints202308.0357.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: Plant extract; LC-MS-ESI; Bioactif compound; Biological activities; Benin
Online: 4 August 2023 (07:41:44 CEST)
Jatropha multifida L. is a plant belong to Euphorbiaceae family used in Benin pharmacopoeia because of its medicinal properties. The objective of this work is to appreciate the therapeutic power of this plant through the evaluation of some of its biological activities. After the preliminary phytochemistry, the polyphenols and flavonoids were quantified and identified by the LC-MS-ESI. The antimicrobial power of the extracts was investigated by agar medium diffusion. The antioxidant power of the extracts was evaluated by the reduction of the DPPH radical, the ABTS radical cation, the feric ion (FRAP) and the lipid peroxidation (LPO). Anti-inflammatory activity was assessed by inhibition of protein (albumin) denaturation. Indeed, different phenolic and flavonoid compounds namely, 2-Hydroxybenzoic acid, o-Coumaroylquinic acid, Apigenin-apiosyl-glucoside, Luteolin-galactoside, Luteolin-glucoside, Luteolin-rhamnoside, Quercetin-glucoside, Quercetin-arabinoside, Dicaffeoyquinic acid, Kaempferol-rhamnoside were identify. The J. mutifida extracts has a bactericidal effect with reference strains of wich CMBs vary from 22.67 mg/ml (S. aureus, S. enteridis, L. monocytogenes and C. albicans) to 47.61 mg/ml (E. coli) and with the meat isolated strains (S. equorum, S. saprophiticus, S. haemoliticus, S. cohnii and S. lentus). Ethanolic extract show the highest DPPH radical scavenging activity (IC50 = 0.72±0.03 mg/ml) while methanolic extract showed the highest ferric ion reduction (46.23±1.10 µgEAA/g). Contrary to the FRAP method, the reducing power with ABTS method of water-ethanolic extract was greater (0.49±0.11 mol ET/g). The same extract show the highest albumin denaturation inhibition power (97.31±0.35%) at 1000µg/ml. J. multifida extracts are rich in bioactive compound with good biological activity
ARTICLE | doi:10.20944/preprints201910.0073.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: leds; elicitor; gynura procumbens; callus; hplc; lc-ms; cyanidin-monoglucosides
Online: 7 October 2019 (12:30:26 CEST)
Conventional fluorescent lamps used in tissue culture are costly light sources showing excessive wavelength emission-bandwidth that must be replaced by alternative, less costly and much lower power-consuming energy sources. The use of Light-Emitting Diodes (LEDs) is the best option due to their potential role as elicitors of secondary metabolite production in many plant models. Gynura procumbens(G. procumbens) is widely used for treating various diseases. Here, leaf explants were cultivated in MS medium supplemented with 0.5 mg/L of NAA and 2.0 mg/L of BAP for 30 days under white, blue, and red LEDs. Secondary metabolites were analyzed by HPLC and LC-MS. Blue LEDs elicited the highest antioxidant activity, total flavonoid, and phenolic content. Furthermore, the content of cyanidin-monoglucosides increased significantly increased under blue light.
ARTICLE | doi:10.20944/preprints202306.1548.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: atorvastatin; ezetimibe; o-hydroxyl atorvastatin; p-hydroxyl atorvastatin; ezetimibe-glucuronide; LC-MS/MS; SALLE; human plasma
Online: 21 June 2023 (12:06:30 CEST)
A simple and sensitive liquid chromatography-tandem mass spectrometry (LC– MS/MS) method has been developed for the simultaneous determination of atorvastatin (ATOR), ezetimibe (EZM) and their three metabolites including o-hydroxyl atorvastatin (o-OH ATOR), p-hydroxyl atorvastatin (p-OH ATOR), and ezetimibe-glucuronide (EZM-G) in human plasma using benzyl paraben (BP) as internal standard (IS). The analytes and IS were ionized using ESI positive ion mode (ATOR, o-OH ATOR, and p-OH ATOR), ESI negative ion mode (EZM, EZM-G, and BP), and operated in multiple reaction monitoring (MRM) mode. They were next extracted by salting-out assisted liquid–liquid extraction with acetonitrile, and then analyzed by liquid chromatography on a reversed-phase chromatographic column (50 mm × 4.6 mm; 3.5 µm), using a mixture of ac-etonitrile and an acetic acid solution (0.5%) as the mobile phase, showing high extraction effi-ciency (>70%), and a minimized matrix effect. The method was satisfactorily validated, and showed excellent linearity over wide concentration ranges of 0.06–15 ng/mL, 0.6–150 ng/mL, 0.4–100 ng/mL, 0.12–30 ng/mL, and 0.05–3 ng/mL for EZM, EZM-G, ATOR, o-OH ATOR, and p-OH ATOR, respectively.
COMMUNICATION | doi:10.20944/preprints202211.0165.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Proteomics; LC-MS/MS; phosphopeptide enrichment; bioinformatics; cellular signaling; Mag-naporthe oryzae; phosphorylation; DDA; DIA; phospho-peptidomics
Online: 9 November 2022 (02:09:17 CET)
The dynamic interplay of signaling networks in most major cellular processes is characterized by the orchestration of reversible protein phosphorylation. Consequently, analytic methods like quantitative phospho-peptidomics has been pushed forward from a highly specialized edge-technique to a powerful and versatile platform for comprehensively analyzing the phosphorylation profile of living organisms. Despite enormous progress in instrumentation and bioinformatics, a major problem remains a high number of missing values caused by the experimental procedure due to either a random phospho-peptide enrichment selectivity or borderline signal intensities, which both cause the exclusion for fragmentation using the commonly applied data dependent acquisition (DDA) mode. Consequently, an incomplete dataset reduces confidence in the subsequent statistical bioinformatic processing. Here, we successfully applied data independent acquisition (DIA) by using the filamentous fungus Magnaporthe oryzae as model organism and could prove that while maintaining data quality (such as phosphosite and peptide sequence confidence), the data completeness increases dramatically. Since the method presented here reduces the LC-MS/MS analysis from 3 h to 1 h and increases the number of phoshosites identified up to 10-fold in contrast to published studies in fungi, we pushed the phospho-proteomic technique beyond its current limits and could provide a sophisticated resource for investigation of signaling processes in filamentous fungi.
ARTICLE | doi:10.20944/preprints201907.0005.v1
Subject: Biology And Life Sciences, Immunology And Microbiology Keywords: Melissa officinalis; antioxidant activity; aflatoxins; anti-aflatoxigenic activity; GC/MS; LC/MS; lemon balm; in situ; Pistachia Vera
Online: 1 July 2019 (11:16:15 CEST)
Lemon balm extracts by dry plant material of Melissa officinalis were tested against their efficacy against for different fungal species Alternaria alternata, Fusarium oxysporum, Aspergillus flavus and Beauveria bassiana. The aqueous phase of the extract was evaluated for antioxidant, antifungal and also anti-aflatoxigenic activity. A synergism evaluation was also performed concerning, the small quantity of lemon balm polar essential oil compounds extracted into the infusion and the water soluble compounds in the extract. The experiments were conducted in solid cultures and the growth inhibition was demonstrated by measuring mycelial diameter. Additionally, the effect on conidia production was also demonstrated. Lemon balm was also used for in situ test on Pistachia vera seed against Aspergillus flavus growth and aflatoxin production. Results revealed enhancement of fungal growth by lemon balm extracts however total inhibition of aflatoxins production on Pistachia vera seeds was observed, and both actions were tried to attributed to volatile and water soluble compounds identified based on GC/MS, HPLC/DAD and LC/MS, and the observed antioxidant activity. Volatile and water - soluble compounds found to be in absolute synergism in mycelium growth enhancement and the observed anti-aflatoxigenic activity addressed to the high antioxidant activity observed and synergistic action between the other water soluble phenolic compounds identified in the extract. The findings of this study underline the high biological active potential of lemon balm extracts under various screening test since for the first time full phytochemical analysis of lemon balm extracts.
ARTICLE | doi:10.20944/preprints202304.0515.v1
Subject: Medicine And Pharmacology, Medicine And Pharmacology Keywords: Flumazenil; LC-QqQ MS; Metabolism; r-aminobutyric acid receptor antagonist; benzodiazepine receptors
Online: 18 April 2023 (10:29:26 CEST)
Studies on the neurobiological causes of anxiety disorders suggest that the GABA system in-creases synaptic concentration and enhances the affinity of GABAA (type A) receptors for ben-zo-diazepine ligands. Flumazenil antagonizes the benzodiazepine binding site of the GABA (γ-aminobutyric acid) type /benzodiazepine receptor (BZR) complex in the central nervous sys-tem (CNS). The integration of the metabolites of flumazenil by LC-tandem mass spectrometry will complete understanding of the in vivo metabolism of flumazenil and accelerate radio-pharmaceutical inspection and registration. The main goal of our study was to investigate using reversed-phase HPLC (PR-HPLC) coupled with electrospray ionization triple quadrupole tan-dem mass spectrometry (ESI-QqQ MS) for the identification of flumazenil and its metabolites in a hepatic matrix. And a carrier-free nucleophilic fluorination with automatic synthesizer for [18F]flumazenil which applied to in vivo nano-positron emission tomography (Nano-PET)/computed tomography (CT) imaging and ex vivo bio-distribution used to analyze in normal rats. The study showed that 50% of the flumazenil was bio-transformed at 60 min by the rat liver homogenate, while one metabolite (M1) was a methyl transesterification product of flumazenil. In a rat liver microsomes system, two metabolites were identified (M2 and M3) as its carboxylic acid and hydroxylated ethylester forms, respectively. [18F]flumazenil in vivo nanoPET/CT imag-ing and ex vivo bio-distribution assay also showed significant effects on GABAA receptor availa-bility in the amygdala, prefrontal cortex, cortex, and hippocampus in the rat brain, worriless about the formation of metabolites. We showed completion of the bio-transformed course of flumazenil by the hepatic system; and [18F]flumazenil can be a good ligand and serve as a PET agent for determination of GABAA/BZR complex for multiplex neurological syndromes in the clinical stage.
ARTICLE | doi:10.20944/preprints201807.0291.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: classification, stingless bee honey, bee species origins, metabolomics, NMR, LC-MS, chemometrics
Online: 16 July 2018 (14:05:59 CEST)
Background: The official standard for quality control of honey is currently based on physicochemical properties. However, this method is time-consuming, cost intensive, and do not lead to information on the originality of honey. This study aims to classify raw stingless bee honeys by bee species origins as a potential classifier using NMR-LCMS-based metabolomics approach. Methods: Raw stingless bee honeys were analysed and classified by bee species origins using proton nuclear magnetic resonance (1H NMR) spectroscopy and an ultra-high performance liquid chromatography-quadrupole time of flight mass spectrometry (UHPLC-QTOF MS) in combination with chemometrics tools. Results: The honey samples were able to be classified into three different groups based on the bee species origins of Heterotrigona itama, Geniotrigona thoracica, and Tetrigona apicalis. D-Fructofuranose (H. itama honey), β-D-Glucose, D-Xylose, α-D-Glucose (G. thoracica honey), and L-Lactic acid, Acetic acid, L-Alanine (T. apicalis honey) identified via 1H NMR data and the diagnostic ions of UHPLC-QTOF MS were characterized as the discriminant metabolites or putative chemical markers. Conclusion: It could be suggested that the quality of honey in terms of originality and purity can be rapidly determined using classification technique by bee species origins via 1H NMR- and UHPLC-QTOF MS-based metabolomics approach.
ARTICLE | doi:10.20944/preprints202110.0415.v1
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: epilepsy; hydrogen sulfide; corneal kindled mice, mitochondrial dysfunction, oxidative stress, LC-MS/MS; temporal lobe epilepsy; neurological disorder; gasotransmitter
Online: 27 October 2021 (13:36:04 CEST)
Epilepsy is a heterogenous neurological disorder characterized by recurrent unprovoked seizures, mitochondrial stress, and neurodegeneration. Hydrogen sulfide (H2S), a gasotransmitter, promotes mitochondrial function and biogenesis, elicits neuromodulation and neuroprotection, and may acutely suppress seizures. A major gap in knowledge remains in understanding the role of mitochondrial dysfunction and progressive changes in H2S levels following acute seizures and during epileptogenesis. We thus sought to quantify changes in H2S and its methylated metabolite (MeSH) via LC-MS/MS subsequent to acute maximal electroshock and 6 Hz 44 mA seizures in mice, as well as in the corneal kindled mouse model of chronic seizures. Plasma H2S was acutely reduced after a maximal electroshock seizure. H2S or MeSH levels in whole brain homogenate and expression of related genes in corneal kindled mice were not altered. However, plasma H2S and MeSH levels were significantly lower during kindling, but not after established kindling. Morever, we demonstrated a time-dependent increase in expression of mitochondrial membrane integrity-related proteins, Opa1, Mfn2, Drp1, and Mff during kindling, which did not correlate with gene expression. Taken together, short-term reductions in plasma H2S could be a novel biomarker for seizures. Future studies should further define the role of H2S and mitochondrial stress in epilepsy.
DATA DESCRIPTOR | doi:10.20944/preprints202305.0963.v1
Subject: Biology And Life Sciences, Biology And Biotechnology Keywords: Ferroptosis; proteomics; LC-MS/MS; mouse embryonic fibroblasts; Pfa1; cell death; glutathione peroxidase 4; erastin; ML210; L-Buthionine-sulfoximine; BSO
Online: 12 May 2023 (14:47:52 CEST)
Ferroptosis is a unique variety of non-apoptotic cell death, driven by massive lipid oxidation in an iron-dependent manner. Since Ferroptosis was introduced as a concept in 2012, it was shown it's essential role in the pathogenesis in neurodegenerative diseases and an important role in therapy-resistant cancer cells. Thus, a detailed molecular understanding of both canonical and alternative ferroptosis pathways are required. There is a set of widely used chemical agents to modulate ferroptosis using different pathway targets: Erastin blocks cystine-glutamate antiporter, system xc-; ML210 directly inactivate GPX4; L-buthionine sulfoximine (BSO) inhibits γ-glutamylcysteine synthetase, an essential enzyme for glutathione synthesis de novo. Most studies were focused on lipidomic profiling of model systems undergoing death in a ferroptotic modality.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: PBMC; polyclonal cell stimulation; complement pathway; plant lectin; Musa paradisiaca; banana lectin; BanLec; LC-MS/MS; proteomics; ELF1; IL-2
Online: 2 August 2021 (13:02:07 CEST)
The aim of the study was to gain deeper insights in the potential for polyclonal stimulation of PBMC from cows and pigs with banana lectin (BanLec) from Musa paradisiaca. BanLec induced a marked proliferative response in cow and pig PBMC. The response in pigs was even higher than to Concanavalin A. Molecular processes associated with respective responses were examined with differential proteome analyses. Discovery proteomic experiments was applied to BanLec stimulated PBMC and cellular and secretome responses were analyzed with label free LC-MS/MS. In PBMC, 3955 proteins were identified. After polyclonal stimulation with BanLec, 459 proteins showed significantly changed abundance in PBMC. In respective PBMC secretomes, 2867 proteins were identified with 231 differentially expressed candidates as reaction to BanLec stimulation. The transcription factor `E74 like ETS transcription factor 1 (ELF1)` was solely enriched in BanLec stimulated PBMC. BanLec induced secretion of several immune regulators, amongst them positive regulators of activated T cell proliferation and Jak-STAT signaling pathway. Top changed immune proteins were CD226, CD27, IFNG, IL18, IL2, CXCL10, LAT, ICOS, IL2RA, LAG3 and CD300C. BanLec stimulates PBMC of cows and pigs polyclonally and induces IL2 pathway and further proinflammatory cytokines. Proteomics data are available via ProteomeXchange with identifier PXD027505.
REVIEW | doi:10.20944/preprints201807.0052.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Plant stress, abiotic stress, biotic stress, metabolomics, phytometabolomics, sensomics, phytohormonics, LC-MS/MS, NMR, targeted metabolomics, untargeted metabolomics, functional food.
Online: 3 July 2018 (14:18:19 CEST)
The breeding of stress-tolerant cultivated plants that would allow for a reduction in harvest losses and undesirable decrease in quality attributes requires a new quality of knowledge on molecular markers associated with relevant agronomic traits, on quantitative metabolic responses of plants on stress challenges, and on the mechanisms controlling the biosynthesis of these molecules. By combining metabolomics with genomics, transcriptomics and proteomics datasets a more comprehensive knowledge of the composition of crop plants used for food or animal feed is possible. In order to optimize crop trait developments, to enhance crop yields and quality, as well as to guarantee nutritional and health factors, that provides the possibility to create functional food or feedstuffs, the knowledge about the plants’ metabolome is crucial. Next to classical metabolomics studies, this review focusses on several metabolomics based working techniques, such as sensomics, lipidomics, hormonomics and phytometabolomics, which were used to characterize metabolome alterations during abiotic and biotic stress, to find resistant food crops with a preferred quality or at least to produce functional food crops are highlighted.
Subject: Medicine And Pharmacology, Oncology And Oncogenics Keywords: glioma; cancer; carnitine; acylcarnitine; solid-phase microextraction SPME; liquid chromatography-mass spectrometry LC-MS
Online: 2 August 2021 (14:42:36 CEST)
Alterations in the carnitine shuttle system may be an indication of the presence of cancer. As such, in-depth analyses of this pathway in different malignant tumors could be important for the detec-tion and treatment of this disease. The current study aims to assess the profiles of carnitine and acylcarnitines in gliomas with respect to their grade, the presence of isocitrate dehydrogenase (IDH) mutations, and 1p/19q co-deletion. Brain tumors obtained from 19 patients were sampled on-site using solid-phase microextraction (SPME) immediately following excision. Analytes were desorbed and then analyzed via liquid chromatography-high resolution mass spectrometry. The results showed that SPME enabled the extraction of carnitine and 22 acylcarnitines. An analysis of the correlation factor revealed presence of two separate clusters: short-chain and long chain car-nitine esters. Slightly higher carnitine and acylcarnitine concentrations were observed in the higher malignancy tumor samples (high vs low grade), and in those samples with worse projected clinical outcomes (without vs with IDH mutation; without vs with 1p/19q co-deletion). Thus, the proposed chemical biopsy approach offers a simple solution for on-site sampling that enables sample preservation, thus supporting comprehensive multi-method analyses.
ARTICLE | doi:10.20944/preprints202002.0019.v1
Subject: Biology And Life Sciences, Endocrinology And Metabolism Keywords: metabolomics; LC-MS; mass spectrometry; metabolic profiling; computational; statistical; unsupervised learning; supervised learning; pathway analysis
Online: 3 February 2020 (05:54:14 CET)
Metabolomics analysis generates vast arrays of data, necessitating comprehensive workflows involving expertise in analytics, biochemistry and bioinformatics, in order to provide coherent and high-quality data that enables discovery of robust and biologically significant metabolic findings. In this protocol article, we introduce NoTaMe, an analytical workflow for non-targeted metabolic profiling approaches utilizing liquid chromatography–mass spectrometry analysis. We provide an overview of lab protocols and statistical methods that we commonly practice for the analysis of nutritional metabolomics data. The paper is divided into three main sections: the first and second sections introducing the background and the study designs available for metabolomics research, and the third section describing in detail the steps of the main methods and protocols used to produce, preprocess and statistically analyze metabolomics data, and finally to identify and interpret the compounds that have emerged as interesting.
ARTICLE | doi:10.20944/preprints202103.0100.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Amphistegina lobifera; Red Sea; pH microsensor; global warming; thermal stress; ocean acidification; large benthic foraminifera; coral reef; LC-MS/MS proteomics; photosymbiotic calcifier
Online: 2 March 2021 (15:52:01 CET)
Reef-dwelling calcifiers face numerous environmental stresses associated with anthropogenic carbon dioxide emissions, including ocean acidification and warming. Photosymbiont-bearing calcifiers, such as large benthic foraminifera, are particularly sensitive. To gain insight into their resistance and adaptive mechanisms to climate change, Amphistegina lobifera from the Gulf of Aqaba were cultured under elevated pCO2 (492, 963, and 3182 ppm) fully-crossed with elevated temperature (28°C and 31°C) for two months. Differential protein abundances in host and photosymbionts amongst treatments were investigated alongside physiological responses and microenvironmental pH variations. Over 1000 proteins were identified, of which one-third varied significantly between treatments. Thermal stress induced protein depletions, along with reduced holobiont growth. Elevated pCO2 caused only minor proteomic alterations and color changes. However, combined stressors reduced pore sizes and increased microenvironmental pH, indicating adaptive modifications to gas exchange. Notably, substantial proteomic variations at moderate-pCO2 and 31°C indicate cellular stress, while stable physiological performance at high-pCO2 and 31°C is scrutinized by putative decreases in test stability. Our experiment shows that the effects of climate change can be missed when stressors are assessed in isolation, and that physiological responses should be assessed across organismal levels to make more realistic predictions for the fate of reef calcifiers.
ARTICLE | doi:10.20944/preprints201909.0017.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: LC-MS; mesenchymal stem cells; stromal cells; fat differentiation; lipidomics; metabolomics; proteomics; multiomics; network analysis; mathematical modelling
Online: 2 September 2019 (06:07:17 CEST)
The molecular study of fat cell development in the human body is essential for our understanding of obesity and related diseases. Mesenchymal stem/stromal cells (MSC) are the ideal source to study fat formation as they are the progenitors of adipocytes. In this work, we used human MSCs, received from surgery waste, and differentiate them into fat adipocytes. The combination of several layers of information coming from lipidomics, metabolomics and proteomics enabled comprehensive analysis of the biochemical pathways in adipogenesis. Simultaneous analysis of metabolites, lipids and proteins in cell culture is challenging due to the compound’s chemical difference so that most studies involve separate analysis with unimolecular strategies. In this study, we employed a multimolecular approach using a two–phase extraction to monitor the crosstalk between lipid metabolism and protein-based signaling in a single sample (~105 cells). We developed an innovative analytical workflow including standardization with in-house produced 13C-isotopically labeled compounds, hyphenated high-end mass spectrometry (high-resolution Orbitrap MS) and chromatography (HILIC, RP) for simultaneous untargeted screening and targeted quantification. Metabolite and lipid concentrations ranged over 3-4 orders of magnitude and were detected down to the low fmol (absolute on column) level. Biological validation and data interpretation of the multiomics workflow was performed based on proteomics network reconstruction, metabolic modelling (MetaboAnalyst 4.0) and pathway analysis (OmicsNet). Comparing MSCs and adipocytes, we observed significant regulation of different metabolites and lipids such as triglycerides, gangliosides and carnitine with 113 fully reprogrammed pathways. The observed changes are in accordance with literature findings dealing with adipogenic differentiation of MSC. These results are a proof of principle for the power of multimolecular extraction combined with orthogonal LC-MS assays and network construction. Considering the analytical and biological validation performed in this study, we conclude that the proposed multiomics workflow is ideally suited for comprehensive follow-up studies on adipogenesis and is fit for purpose for different applications.
ARTICLE | doi:10.20944/preprints201812.0069.v2
Subject: Biology And Life Sciences, Plant Sciences Keywords: chlorophylls; LC-MS-based proteomics; pea (Pisum sativum L.); proteome functional annotation; proteome map; seeds; seed proteomics
Online: 13 December 2018 (14:09:06 CET)
Due to low culturing costs and high seed protein contents, legumes represent the main global source of food protein. Pea (Pisum sativum L.) is one of the major economically important legume crops, impacting both animal feed and human nutrition. Therefore, the quality of pea seeds needs to be ensured in the context of sustainable crop production and nutritional efficiency. Obviously, changes in seed protein patterns might directly affect both of these aspects. Thus, here we address the pea seed proteome in more detail and provide, to the best of our knowledge, the most comprehensive annotation of the functions and intracellular localization of pea seed proteins. Accordingly, 1938 and 1989 non-redundant proteins were identified in yellow and green pea seeds, in total. Only 35 and 44 proteins, respectively, could be additionally identified after protamine sulfate precipitation (PSP) potentially indicating the high efficiency of our experimental workflow. In total 981 protein groups could be assigned to 34 functional classes, which were to a large extent differentially represented in yellow and green seeds. Closer analysis of these differences by processing of the data in KEGG and String databases revealed their possible relation to a higher metabolic status and reduced longevity of green seeds.
REVIEW | doi:10.20944/preprints202206.0040.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Microsampling; sample miniaturisation; dried blood spot (DBS); dried plasma spot (DPS); dried serum spot (DSS); metabolic phenotyping; gas chromatography-mass spectrometry (GC-MS); liquid chromatog-raphy-mass spectrometry (LC-MS)
Online: 3 June 2022 (09:53:13 CEST)
Microsamples (collections usually less than 50 µL) have been introduced in pre-clinical, clinical, and research settings to overcome obstacles in sampling via traditional venipuncture. However, venipuncture remains the sampling gold standard for metabolic phenotyping of blood. This pre-sents several challenges in metabolic phenotyping workflows: accessibility for individuals in ru-ral and remote underserved areas (due to the need for trained personnel), the unamenable nature to frequent sampling protocols in longitudinal research (for its invasive nature), and sample col-lection difficulty in the young and elderly. Furthermore, venous sample stability may be compro-mised when temperate conditions necessary for cold-chain transport are beyond control. Alter-natively, research utilising microsamples extends phenotyping possibilities to inborn errors of metabolism, therapeutic drug monitoring, nutrition, as well as sport and anti-doping. Although the application of microsamples in metabolic phenotyping exists, it is still in its infancy, with whole blood being overwhelmingly the primary biofluid collected through the collection method of dried blood spots. Research into metabolic phenotyping of microsamples is limited; however, with advances in commercially available microsampling devices, common barriers such as volumetric inaccuracies and the ‘haematocrit effect’ in dried blood spot microsampling can be overcome. In this review, we provide an overview of the common uses and workflows for mi-crosampling in metabolic phenotyping research. We discuss the advancements in technologies, highlighting key considerations and remaining knowledge gaps for employment of microsamples in metabolic phenotyping research. Supporting the translation of research from the ‘bench to the community’.
ARTICLE | doi:10.20944/preprints202304.0459.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Deucravacitinib; HPLC-MS/MS; Psoriasis; Human plasma
Online: 18 April 2023 (02:51:35 CEST)
Plaque psoriasis is a common, long-lasting illness that affects the immune system and causes significant negative impacts on a patient's physical health, well-being, and ability to work effectively. Deucravacitinib (DEU) is the first oral medication used in the treatment of plaque psoriasis, a chronic skin condition that causes red, scaly patches on the skin. DEU is a type of medication called an oral Janus kinase (JAK) inhibitor, which works by blocking specific enzymes that play a role in the inflammation and immune response associated with psoriasis. Therefore, a quick, easy, novel, reliable, sensitive, and straightforward Liquid Chromatography-Tandem Mass Spectrometry (LC-MS/MS) approach was used to analyse DEU in plasma samples. The LC-MS/MS method for the determination of DEU in human plasma was based on using trimethoprim as an internal standard (IS). The separation of DEU and IS was carried out via liquid-liquid extraction (LLE). The isolated substances were then subjected to the chromatographic system using the ACE-C18 column (4.6x100 mm, 5 µm). The mobile phase employed consisted of methanol and a solution of 2 mM ammonium formate (80:20 v/v, respectively). The flow rate used was set at 0.9 mL min-1. The creative strategy was performed by running an ABSCIEX API 4000 mass spectrometer with an electron spray ionization source in Multiple Reaction Monitoring (MRM) modes. The ion transitions m/z 426.3 358.2 was used for DEU quantitation, while the ion transitions m/z 291.1 261.1 was used for trimethoprim quantitation. The accuracy, precision, linearity, recovery, and selectivity of DEU were deemed acceptable when validated for a concentration range between 0.500 to 601.050 ng/mL, utilizing a weighting factor of 1/x2.
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: glycolipidomics; GIPC; glycosyl inositol phospho ceramides; Lipid Data Analyzer; lipidomics; sphingolipids; ultra-high pressure liquid chromatography; high-resolution mass spectrometry; LC-MS; automated annotation
Online: 8 September 2020 (12:34:56 CEST)
Glycosyl inositol phospho ceramides (GIPCs) are the major sphingolipids on earth as they account for a considerable fraction of the total lipids in plants and fungi which in turn represent a large portion of the biomass on earth. Despite their obvious importance, GIPC analysis remains challenging due to the lack of commercial standards and automated annotation software. In this work, we introduce a novel GIPC glycolipidomics workflow based on reversed-phase ultra-high pressure liquid chromatography coupled to high-resolution mass spectrometry. For the first time, automated GIPC assignment was performed using the open-source software Lipid Data Analyzer based on platform-independent decision rules. Four different plant samples (salad, spinach, raspberry, strawberry) were analyzed and revealed 64 GIPCs based on accurate mass, characteristic MS2 fragments and matching retention times. Relative quantification using lactosyl ceramide for internal standardization revealed GIPC t18:1/h24:0 as the most abundant species in all plants. Depending on the plant sample, GIPCs contained mainly amine, N-acetylamine or hydroxyl residues. Most GIPCs revealed a Hex-HexA-IPC core and contained a ceramide part with a trihydroxylated t18:0 or t18:1 long chain base and hydroxylated fatty acid chains ranging from 16 to 26 carbon atoms in length (h16:0 – h26:0). Interestingly, six GIPCs containing t18:2 were observed in raspberry, which was not reported so far. The presented workflow supports the characterization of different plant samples by automatic GIPC assignment potentially leading to the identification of new GIPCs. For the first time, automated high‑throughput profiling of these complex glycolipids is possible by liquid chromatography-high-resolution mass spectrometry and subsequent automated glycolipid annotation based on decision rules.
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Pesticide residue /GC- MS/MS/m-PFC/Wine
Online: 3 September 2021 (17:16:15 CEST)
A convenient and fast multiresidue method for the efficient identification and quantification of 72 pesticides belonging to different chemical classes in red and white grape wines have been developed. The analysis was based on gas chromatography tandem quadrupole mass spectrometric determination (GC–MS/MS). An optimization strategy involved the selection of MWCNTs amount and cleanup procedure cycle times for m-PFC was performed to achieve ideal recoveries and reduce sample matrix compounds in the final extracts. The optimized procedure obtained consistent recoveries between 70.2 and 108.8% (70.2% and 108.8% for white wine, 72.3% and 106.0% for red wine) , with relative standard deviations (RSDs) generally lower than 8.3% at three spiking levels of 0.01, 0.05 and 0.2 mg/kg. Linearity was studied in the range between 0.005 and 0.2 mg/kg using pesticide standards prepared both in pure solvent and in the presence of matrix, showing coefficients of determination (R2) higher than 0.985 for all the pesticides. To improve accuracy, matrix matched calibration curves were used for calculating the quantification results. Finally, the method was used successfully in detecting pesticide residues in commercial gape wines.
ARTICLE | doi:10.20944/preprints201612.0023.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: UPLC-MS/MS; mycotoxins; feedstuffs; flow-through; multiple analysis
Online: 5 December 2016 (09:40:24 CET)
A novel determination method using flow-through cartridge purification and ultra-high-performance liquid chromatography coupled to tandem mass spectrometry (UPLC-MS/MS) was developed for the identification and quantification of 30 mycotoxins (aflatoxin B1, B2, G1, G2, sterigmatocysin, T-2 toxin, diacetoxyscirpenol, roquefortine C, methylergonovine, ergocornine, lysergol, enniatin A, enniatin A1, enniatin B, enniatin B1, beauvericin, deoxynivalenol, 3-acetylDeoxynivalenol, 15-acetylDeoxynivalenol, patulin, verruculogen, neosolaniol, gliotoxin, HT-2 toxin, wortmannin, zearalenone, α-zearalenol, β-zearalenol, α-zearalanol, and β-zearalanol) in feedstuffs. Mycotoxins were extracted from sample by 0.1% formic acid aqueous solution/acetonitrile (16/84 v/v), then purified by a Cleanert® MC clean-up column. As a result, the pigments and other matrices were efficient removed from the sample extract solution. The purified eluate was collected, then evaporated and redissolved by 0.1% formic acid aqueous solution/acetonitrile (70:30 v/v) for UPLC-MS/MS detection. A BEH Shield RP18 chromatographic column was employed for separation of 30 mycotoxins in a total of 14 min. Multiple-reaction monitoring (MRM) mode was applied for qualitative and quantitative analysis, and matrix calibration curves obtained with the external-standard method was used for quantitation of target analytes. Under optimized conditions, the linearity range was from 2 to 1000 ng/g, and the limit of quantification of the developed method was from 2 to 50 ng/g. The recoveries of 30 mycotoxins spiked in urine samples were from 72.0% to 118.5%, and the relative standard deviation was below 20%. The method was also well approved by certified reference sample, and applied on the real feedstuff samples testing successfully.
ARTICLE | doi:10.20944/preprints202306.1846.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Untargeted metabolomics; HPLC-ESI-MS/MS; Curcuma longa; GNPS; Diarylheptanoids
Online: 27 June 2023 (04:47:44 CEST)
Turmeric, Curcuma longa L., is a type of medicinal plant characterized by its perennial nature and rhizomatous growth. It is a member of the Zingiberaceae family and is distributed across the world’s tropical and subtropical climates, especially in South Asia. Its rhizomes are highly valued for food supplements, spices, flavoring agents, and yellow dye in South Asia since ancient times. It exhibits a diverse array of therapeutic qualities that encompass its ability to combat diabetes, reduce inflammation, act as an antioxidant, exhibit anticancer properties, and promote anti-aging effects. In this study, organic extracts of C. longa rhizomes were subjected to HPLC separation followed by mass spectrometry analysis. The Global Natural Product Social Molecular Networking (GNPS) approach was utilized for the first time in this ethnobotanically important species to conduct an in-depth analysis of its metabolomes based on their fragments. A total of 30 metabolites including 16 diarylheptanoids, 1 diarylpentanoid, 3 bisabolocurcumin ethers, 4 sesquiterpenoids, 4 cinnamic acid derivatives, and 2 fatty acid derivatives were identified. Among 16 diarylheptanoids identified in this study, five of them are reported for the first time in this species.
ARTICLE | doi:10.20944/preprints202110.0369.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Macrocyclic lactones; agricultural crops; food; sample preparation; UHPLC-MS/MS
Online: 25 October 2021 (15:50:47 CEST)
Soybean, maize and bean are crops of great economic importance, but in the last years suffered with infestations of the caterpillar Helicoverpa armigera, being the main problem the resistance of this pest to most pesticides. Avermectin emamectin benzoate was recently released to control this pest. Other avermectins, like abamectin, doramectin, eprinomectin and ivermectin are used in large scale because they potent acaricidal, anthelmintic, and insecticidal activities. Thus, a simple and fast method for the determination of avermectins in these crops based on a quick, easy, cheap, effective, rugged and safe (QuEChERS) extraction procedure and ultra-high performance liquid chromatography with tandem mass spectrometry (UHPLC-MS/MS) analysis was developed and validated. For extraction, water followed by acetonitrile:isopropanol and a partition step with salts was stablished. With the clean-up step using activated EMR-Lipid, limits of detection of 1.2 μg kg-1 for abamectin, doramectin, emamectin benzoate and ivermectin, and of 2.4 μg kg-1 for eprinomectin were achieved. Accuracy and precision evaluated at low levels presented satisfactory results. The method was successfully applied in commercial samples and is a good alternative for routine analysis.
ARTICLE | doi:10.20944/preprints201908.0263.v1
Subject: Chemistry And Materials Science, Physical Chemistry Keywords: 3-MBA; gold clusters; ESI-MS; HPLC-MS; bidentate binding
Online: 26 August 2019 (11:08:56 CEST)
Gold clusters protected by 3-MBA ligands (MBA = mercaptobenzoic acid, -SPhCO2H) have attracted recent interest for their unusual structures and advantageous ligand-exchange and bioconjugation properties. Azubel et al. first determined the core structure of an Au68-complex, which was estimated to have 32 ligands (3-MBA groups). To explain the exceptional structure-composition and reaction properties of this complex, and its larger homologs, Tero et al. proposed a “dynamic stabilization” via carboxyl O-H--Au interactions. Herein, we report the first results of an integrated LC/MS analysis of unfractionated samples of gold / 3-MBA clusters, spanning the narrow size range 13.4 to 18.1 kDa. Using high-throughput procedures adapted from bio-macromolecule analyses, we show that integrated capillary HPLC-ESI-MS, based upon aqueous-methanol mobile phases and ion-pairing reverse-phase chromatography, can separate several major components from the nanoclusters mixture that may be difficult to resolve by standard native gel electrophoresis due to their similar size and charge. For each component, one obtains a well-resolved mass spectrum, nearly free of adducts or signs of fragmentation. A consistent set of molecular mass determinations is calculated from detected charge-states tunable from 3- (or lower), to 2+ (or higher). One thus arrives at a series of new compositions (n, p) specific to the Au/3-MBA system. The smallest major component is assigned to the previously unknown (48, 26); the largest one is evidently (67, 30), vs. the anticipated (68, 32). Various explanations for this discrepancy are considered. A prospective is given for the several members of this novel series, along with a summary of the advantages and present limitations of the micro-scale integrated LC/MS approach to characterize such metallic-core macro-molecules, and their derivatives.
ARTICLE | doi:10.20944/preprints201805.0175.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Tamarix nilotica; Tamaricaceae; polyphenols; HPLC/HRESI/MS/MS; antifibrotic activity
Online: 11 May 2018 (05:18:58 CEST)
Tamarix nilotica (Ehrenb.) Bunge (Tamaricaceae), an indigenous plant to the Middle East region, is well-known as a medicinal plant for treating many human ailments. The current study aimed at exploring the polyphenols profile of T.nilotica alcohol soluble fraction of aqueous extract, assessing its in-vivo antifibrotic activity and the possible underlying mechanism, to unravel the impact of quantitative difference of sulphated polyphenols content on the antifibrotic activity of T.nilotca grown in two different habitats. Polyphenols profiling of T. nilotica extracts was performed using HPLC-HRESI-QTOF-MS-MS. The major polyphenol components included sulphated flavonoids, phenolic acids and free aglycones. The antifibrotic activity was evaluated through carbon tetrachloride-induced liver fibrosis in rats. Biochemical evaluations revealed that both fractions ameliorated the increased levels of hepatic aminotransferases, lipid peroxidation, hydroxyproline, α-smooth muscle actin (α-SMA), tumor necrosis factor-α (TNF-α), cyclooxygenase-2 (COX-2) and nuclear factor kappa B (NF-κB). Moreover, both fractions reduced catalase activity (CAT) and enhanced hepatic glutathione (GSH) content. Histopathological imaging undoubtedly confirmed such results. In conclusion, T. nilotica polyphenols rich fraction exhibited potential antifibrotic activity in rats. Significant alterations in GSH levels were recorded based on sulphated polyphenol metabolites content.
ARTICLE | doi:10.20944/preprints201803.0209.v2
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Mitracarpus scaber Zucc.; pentalogin; anti-inﬂammatory; MS/MS; Il-8
Online: 10 May 2018 (11:51:09 CEST)
Re-investigation of the chemical composition of the annual plant Mitracarpus scaber Zucc. led to the identification of clarinoside, a new pentalogin derivative containing a rare quinovose moiety, and the known compound harounoside. While the planar structure was fully determined using tandem MS and quantum mechanics calculations (QM), the tridimensional structure was unravelled after isolation and NMR analysis. The absolute configuration was assigned by comparison of experimental and theoretical SRCD spectra. Both compounds were tested for anti-inflammatory activity and compound 1 showed the ability to inhibit the production of interleukin-8 (Il-8) with an IC50 of 9.17 µM.
ARTICLE | doi:10.20944/preprints201705.0113.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Solanum nigrum; anthocyanins purification; HPLC-MS/MS; antioxidant capacity; SnMYB
Online: 15 May 2017 (17:31:53 CEST)
Solanum nigrum fruits have been conventionally available as a material of beverage due to its nutritional substances such as minerals, vitamins, amino acids, proteins, sugars, polyphenols and anthocyanins. Here has rarely reported on the characterizaton of the components and the regulatory mechanism of Anthocyanins in S. nigrum. In this study, we determined that the peel and flesh of S. nigrum fruits shared the similar HPLC profiles, but the different contents and total antioxidant activities for Anthocyanins. After an efficient purification method mainly including extraction with pH 1.0 distilled water and then desorption with pH 1.0 95% ethanol after a DM-130 resin adsorption step to obtain more pure anthocyanins extracts, the purity of anthocyanins extract from S. nigrum fruits reached to 56.1%. Moreover, eight anthocyanins from S. nigrum fruit were identified with HPLC-MS/MS for the first time. A typical R2R3-MYB transcription factor gene, SnMYB, was also cloned for the first time by RACE-PCR from S. nigrum. Moreover, the contents of anthocyanins was shown a good correlation (r = 0.93) with the expression levels of SnMYB during the fruits developmental stages. Most significantly, SnMYB successfully produced high anthocyanins contents (1.03 mg/g) when SnMYB was transiently expressed in tobacco leaves. Taken together, S. nigrum fruits are a promising resource for anthocyanins extraction and SnMYB is an activator that positively regulates anthocyanins biosynthesis in S. nigrum.
ARTICLE | doi:10.20944/preprints202310.1742.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: vitamin D; sports nutrition; personalized nutrition; microsampling; VAMS; HPLC-MS/MS
Online: 27 October 2023 (07:14:35 CEST)
Vitamin D is crucial for athletes' health and performance. Although the exact vitamin D requirements for athletes have not been established, maintaining 25(OH)D levels of at least 40 ng/ml is considered beneficial. This study aimed to determine whether an individual loading dose formula for vitamin D supplementation is suitable to meet a target value of 40 ng/ml and is more effective than standardized supplementation. In a 10-week supplementation study during the winter months in Germany, 90 athletes with insufficient vitamin D levels (25(OH)D<30ng/ml) were randomly assigned to receive either a universal dose of 2000 IU/day of vitamin D or a loading dose of 4000 IU/day, followed by a maintenance dose of 1000 IU/day. Total 25(OH)D concentration was measured from dried blood spots at three time points: at baseline, at the computed date of 40ng/ml, and after the 10-week period. Additionally, a vitamin D-specific questionnaire was issued. On the day when 25(OH)D blood concentrations of 40 ng/ml were calculated to prevail, the individualized group had a significantly higher 25(OH)D level than the standardized group (41.1+-10.9 ng/ml vs. 32.5+-6.4 ng/ml, p<0.001). This study demonstrated that the examined formula is suitable for athletes to achieve a 25(OH)D concentration of 40 ng/ml. This indicates that a personalized approach is more effective than a one-size-fits-all approach in restoring adequate vitamin D levels in athletes.
ARTICLE | doi:10.20944/preprints202308.0341.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: pesticides; permeation; apple peel; Franz diffusion cell; QuEChERS; GC-MS/MS
Online: 3 August 2023 (11:22:42 CEST)
In this study, a new approach to pesticide permeation through the apple peel into the pulp is discussed. The tested compounds can be classified, based on mode of action, as systemic (boscalid, cyprodinil, pirimicarb, propiconazole and tebuconazole) or contact (captan, cypermethrin and fludioxonil) pesticides. The barrier effect was assessed using a Franz flow-type vertical diffusion cell system. Residue analysis was performed using a modified quick, easy, cheap, efficient, rugged and safe (QuEChERS) extraction method coupled to gas chromatography with tandem mass spectrometry (GC-MS/MS). The limits of detection (LODs) ranged between 2.6 µg kg-1 (pirimicarb) and 17 µg kg-1 (captan), with the coefficient of variability (CV) lower than 6%, while recoveries ranged from 85% (boscalid) to 112% (captan) at 0.1 and 1 mg kg-1 spiked levels. The highest peel penetration was observed for pirimicarb, captan and cyprodinil, with cumulative permeation of 90, 19 and 17 µg cm-2, respectively. The total absorption was in the range from 0.32% (tebuconazole) to 32% (pirimicarb). Only cypermethrin was not quantitatively detected in the pulp and its use can be recommended in crop protection techniques. The obtained results indicate that molecular weight, octanol-water partition coefficient and water solubility are important parameters determining the process of pesticide absorption.
ARTICLE | doi:10.20944/preprints202102.0538.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: MRM; Triazoles; GC-MS/MS; DON; ELISA; T-2 Toxin; Wheat
Online: 24 February 2021 (10:05:26 CET)
Wheat is one of the global strategic crops and ranks third in terms of cereals production. Wheat crop is exposed to many fungal infections during the cultivation stages, some of which have the ability to secrete numbers of toxic secondary metabolites that threaten the quality of grains, consumer health, producer economics and global trade exchange. Fifty-four random samples were collected from wheat which originated from different countries. The samples included 14 of soft wheat to study the extent of their contamination with Deoxynivalenol (DON) and T-2 toxin by auto-ELISA technology and r-biopharm Microtiter plate. All samples were contaminated with DON toxin except one sample, and the contamination average ranged between 40.7 and 1018.8 µg kg-1. The highest contamination rates were in Lithuanian and the lowest in Indian wheat. Meanwhile the highest average level of T-2 toxin contamination was in Lithuanian wheat grains with a rate of 377.4µg kg-1 and the lowest in Polish wheat with an average of 115.3µg kg-1. GC-MS/MS and multiple reaction monitoring mode (MRM), was used to detect 15 triazole derivatives in collected samples, which may be used to combat fungal diseases on wheat during the growing season. Only 9 derivatives were found; Simeconazole, Penconazole, Hexaconazole, Cyproconazole, Diniconazole, Tebuconazole, Metconazole, Fenbuconazole and Difenoconazole. These derivatives varied according to the origin of wheat samples as well as their its concentration whereas, another 6 derivatives were not detected in all samples. A direct inverse relationship was found between the DON concentration in the samples and the residues of Simeconazole, Penconazole, Diniconazole, Tebuconazole, Metconazole, Fenbuconazole and Difenoconazole and the T-2 toxin showed the same relationship except for Tebuconazole. The safe and rational use of some triazole derivatives may be a new approach and a promising strategy not only to reduce plant diseases and their problems, but also to get rid of some mycotoxins as contaminates.
ARTICLE | doi:10.20944/preprints202009.0055.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: mortiño; Vaccinium floribundum; HPLC-MS/MS; anthocyanins; antioxidant; antimicrobial; toxicity; Zebrafish.
Online: 3 September 2020 (04:43:08 CEST)
Andean blueberries are wild berries grown and consumed in Ecuador which contain high values of bioactive compounds, mainly anthocyanins, with powerful antioxidant activity. The aim of this study was to evaluate the profile and contents of (poly)phenols and carotenoids in Andean blueberry by HPLC-DAD-MSn and determine a wide range of its biological activities. The antioxidant capacity of this fruit was evaluated in vitro by three different methods and in vivo using the zebrafish animal model, also the toxicity effect was determined by the zebrafish embryogenesis test. Besides, the antimicrobial activity and the capacity of Andean blueberry to produce hemagglutination in blood cells were evaluated. Finally, the bioaccessibility of (poly)phenols and related antioxidant capacity were determined in the different phases of an in vitro digestion. The global results indicated no toxicity of Andean blueberry, weakly bacteriostatic activity, and high contents of anthocyanins and antioxidant capacity, which were partially bioaccesible in vitro (~ 50 % at the final intestinal step), contributing to the knowledge of its health benefits for consumers and its potential use in the food and pharmaceutical industry as functional ingredient.
ARTICLE | doi:10.20944/preprints202305.0866.v1
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: LC gas sensor; novel structure; ZnO nanowires; NO2
Online: 11 May 2023 (13:52:16 CEST)
This work presents an LC resonant passive wireless gas sensor with a novel structure designed to mitigate the negative impact of substrate. The LC sensor antenna with the new structure and the reader antenna were designed and optimized utilizing HFSS software to improve the transfer efficiency. The superiority of the designed structure compared with the general ones is highlighted and verified. The change in the substrate capacitance has essentially no interference with the parameters to be measured of the LC sensor. The sensor with the new structure was prepared by combining etching and sputtering methods. The structure of the ZnO nanowires (NWs) was characterized to confirm their high purity and wurtzite crystal structure. The LC gas sensors demonstrated excellent wireless sensing performance including a low detection limit of 0.5 ppm NO2, high response of 1.058 and outstanding stability at 180 °C. The developed new sensor structure not only prevented interference from the substrate during gas sensing testing, but also expanded the choice of sensor substrates, playing a critical role in the development of sensors based on LC resonance principle.
ARTICLE | doi:10.20944/preprints202311.1192.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Cathinone; Cathine; Kinetics; HPLC-IT/MS; Disposition; Organ-specific response; UPLC-QTOF/MS
Online: 20 November 2023 (07:36:02 CET)
Cathinone is a natural stimulant found in Catha edulis and commonly used in new psychoactive substances. The objective of this study was to examine the disposition kinetics and metabolic profile of cathinone and its metabolite cathine through a single oral dose of cathinone administration in rats. Cathine and cathinone concentrations were identified and quantified using ion trap liquid chromatography (LC-IT/MS), while the metabolic profile was determined using the quadrupole time of flight UPLC-QTOF/MS method in the serum, brain, lung, liver, kidney, and heart over a period of 0, 0.5, 2.5, 6, 12, 24, 48, and 72 hours. The findings revealed a dynamic interplay between the pharmacokinetics of cathinone and its impact on organ-specific biomarkers. The distribution of cathinone and cathine was determined in serum, brain, heart, lung, kidney, and liver. The highest concentration of cathinone was found in the kidney at 1438.6 ug/L. It gradually decreased to 1.97 within 48 hours and disappeared after 72 hours. Within half an hour, cathinone levels in the lungs, liver, and heart were found to be 859, 798.9, and 385.8 ug/L, respectively. However, within 2.5 hours, these levels decreased to 608.1, 429.3, and 309.1 ug/L and kept decreasing until they became undetectable after 24 hours. The concentration of cathinone in the rat brain reduces quickly, dropping to undetectable levels within six hours, with levels decreasing from 712.7 ug/L after just 30 minutes. In the brain and serum, cathine reached its highest levels at 2.5 hours, while in other organs, it peaked at 0.5 hours. This indicates that the conversion of cathinone to cathine is slower in the brain and serum. The study found that cathinone's pharmacokinetics have a significant impact on organ-specific biomarkers. After administering the cathinone, there was a sharp change in biomarker levels, particularly in the liver and brain, during the initial hours. It is essential to investigate the correlation between the changes in biomarkers found in the brain and the levels of cathinone and cathine. The results have significant implications for drug development, pharmacovigilance, and clinical practices involving cathinone. In conclusion, this comprehensive analysis of cathinone's impact on organ-specific biomarkers provides a basis for informed decision-making in medical practices and further research into the cathinone's pharmacological properties.
ARTICLE | doi:10.20944/preprints202309.1861.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: Acrylamide; antioxidant activity; brewing methods; chlorogenic acids; coffee; HPLC-MS/MS; HPLC-DAD.
Online: 28 September 2023 (04:32:53 CEST)
The aim of this study was to investigate the parameters affecting the extraction of positive molecules such as chlorogenic acids and antioxidants, as well as potentially carcinogenic substances such as acrylamide, in different coffee brewing methods. Three coffee varieties, each assigned to different roasting degree, were used to prepare coffee brews following eight diverse preparation methods. Acrylamide was quantified by HPLC-MS/MS instrument while chlorogenic acids and caffeine by HPLC-DAD system. Three spectrophotometric analyses were also performed (DPPH, TFC and TPC) to evaluate antioxidant activity as well. The results showed that the main brewing parameters, that have the greatest influence on the final content of these compounds were the volume of water used, more specifically the brewing ratio (coffee to water ratio), the extraction time and the particle size of the coffee powder.
ARTICLE | doi:10.20944/preprints202011.0177.v1
Subject: Biology And Life Sciences, Anatomy And Physiology Keywords: Propolis Flavonoid; UPLC-Q/TOF-MS/MS; immunological enhancement; Ferulic acid; Anti-PPV
Online: 4 November 2020 (08:50:29 CET)
Propolis was widely used in health preservation and disease healing, it contains many ingredients. The previous study had been revealed that the propolis has a wide range of efficacy, such as antiviral, immune enhancement, anti-inflammatory and so on, but its antiviral components and underlying mechanism of action remain unknown. In this study, we investigated the chemical composition, and anti-PPV and immunological enhancement of Propolis Flavonoid(PF). Chemical composition of PF was distinguished by UPLC-Q/TOF-MS/MS analysis.The presence and characterized of 26 major components was distinguished in negative ionization modes.To evaluate the effects of PF used as adjuvant on the immune response porcine parvovirus (PPV). Thirty Landrace-Yorkshire hybrid sows were randomly assigned to 3 groups, and the sows in adjuvant groups were intramuscular injected PPV vaccine with 2.0 mL PF adjuvant (PA), oilemulsion adjuvant (OA), respectively. After that, serum hemagglutination inhibition antibody titers, IgM and IgG subclasses, eripheral lymphocyte proliferation activity, and concentrations of cytokines were measured. Results indicated an enhancing effect of PA on IgM, IL-2, IL-4, IFN-γ and the IgG subclass responses. These findings suggested that PA could significantly enhance the immune responses. Furthermore, we screened the chemical components the effective of anti-PPV, Ferulic acid have an excellently anti-PPV effective.
COMMUNICATION | doi:10.20944/preprints202212.0070.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: diester chlorogenoborate complex; green coffee bean; HPTLC/UV; HPTLC/ESI–MS; UHPLC/MS; FTIR
Online: 5 December 2022 (09:08:41 CET)
The natural compounds of boron have many applications, including as dietary supplement. Communication is based on the discovery that diester chlorogenoborate complex can be detected and quantified from green coffee bean. The study reports that such diester molecule can also be synthesized in stable form by direct reaction of boric acid and chlorogenic acid, in a mixture of acetonitrile–water (1:1, v/v), left to evaporate over a period of 48 hours, at room temperature, resulting a spirocyclic form (diester complex). The diester complex, with its molecular structure and digestibility attributes has potential application as prebiotic in gut health, oral health and as micronutrient essential for microbiota to human and animals.
ARTICLE | doi:10.20944/preprints201807.0267.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: Filuferru; spirit; distillation; grape marc; volatile compounds; copper; trace elements; GC-MS; ICP-MS; PCA
Online: 16 July 2018 (09:23:20 CEST)
Traditional Filuferru is an ancient spirit from Sardinia, Italy, usually obtained from the distillation of wine or grape marc. In this contribution, the results of the first chemical characterization of a wide number of craft Filuferru samples has been accomplished in terms of evaluation of the alcoholic strength, qualitative and quantitative GC-MS analysis of the volatile composition of the distillate, and its trace element composition by means a ICP-MS method. Both instrumental methods have been validated and applied on 21 craft samples of Filuferru, whereas one sample of commercial distillate has been analyzed for comparison purposes. Alcoholic strength ranged between 41.0 and 62.4% (v/v). Sixty volatile compounds were identified and ten of them have been quantified. Analogies and differences with Grappa (i.e. the Italian distilled spirit most close to Filuferru) have been highlighted in the qualitative and quantitative profile of this matrix. Often meaningful amounts of acetaldehyde, ethyl acetate, dietyl acetal and acetic acid were measured. Elemental analysis, performed on toxic, non-toxic elements and oligoelements, 18 in total, revealed a wide variability of concentrations in both analytes and samples. High concentrations of Cu are sometimes evidenced, likely caused by losses from the distillation apparatus. The principal components analysis (PCA) allowed the differentiation of the ten volatile compounds quantified in two groups: the former, described mainly by PC1, constituted by acetic acid, ethyl acetate, dietyl acetal and acetaldehyde, and the second, described by PC2, constituted by 1-propanol, 2-methyl-1-propanol, the two coeluiting isomers 2-methyl-1-butanol and 3-methyl-1-butanol,1-hexanol, 2-phenylethanol and 2,3-butanediol. Data obtained may be useful in order to establish a regulation for the production of high-quality traditional Filuferru from Sardinia.
REVIEW | doi:10.20944/preprints202311.0668.v1
Subject: Physical Sciences, Optics And Photonics Keywords: tunable LC lenses; orbital angular momentum; optical vortex generation; axico
Online: 13 November 2023 (09:55:43 CET)
Tunable circular devices made of liquid crystals or other materials, like lenses, axicons or phase plates are often constrained by limitations in size, tunability, power and other parameters. These constrains restrict their use and limit their applicability. In this review, a thorough study of the use of light orbital angular momentum in LC devices manufacturing is presented. Twisted light amazingly fosters the simultaneous optimization of most critical parameters. Experimental demonstrations of unmatched performance of tunable LC lenses, axicons and other elements, in magnitudes such as lens diameter (> 1”), power and tunability (> ±6 diopters), fill factor (> 98%) and time response have been achieved by reversible vortex generation created by azimuthal phase delay. This phase delay can be eventually removed within the optical system, so that the lens performance is not affected.
REVIEW | doi:10.3390/sci1010031
Subject: Chemistry And Materials Science, Materials Science And Technology Keywords: separation technique; spectroscopic technique; hyphenated techniques; LC-NMR; natural products
Online: 14 June 2019 (00:00:00 CEST)
LC–NMR combines the advantage of the outstanding separation power of liquid chromatography (LC) and the superior structural elucidating capability of nuclear magnetic resonance (NMR). NMR has proved that it is a standout detector for LC by providing maximum structural information about plant originated extracts particularly in its isolating ability of isomeric (same molecular formula) and/or isobaric (same molecular weight) compounds as compared to other detectors. The present review provides an overview of the LC–NMR developmental trends and its application in natural products analysis. The different LC–NMR operational modes are described, as well as how technical improvements assist in establishing this powerful technique as an important analytical tool in the analysis of complex plant-derived compounds. On-flow, stop-flow and loop-storage modes, as well as the new offline mode LC–SPE–NMR and capLC-NMR configurations that avoid the ingestion of expensive deuterated solvents throughout the experiment are mentioned. Utilization of cryogenic probe and microprobe technologies which are the other important promising approaches for guaranteeing the sensitivity issues are also described. Concluding remarks and future outlooks are also discussed.
ARTICLE | doi:10.20944/preprints202112.0340.v2
Subject: Physical Sciences, Particle And Field Physics Keywords: Anomalous spin g factor; Lepton charge (LC); Neutrino magnetic moment; Weak force decay; EC and LC partial masses; Three-dimensional quantized space model (TQSM)
Online: 1 March 2022 (11:25:10 CET)
The spin magnetic moments and spin g factors (gs = -2) of electron, muon and tau are explained based on the electric charges (EC) and lepton charges (LC) in terms of the three-dimensional quantized space model. The spin g factors of electron, muon and tau are gs = -2 which is the sum of the EC g factor (gEC = -1) and the LC g factor (gLC = -1). The spin g factor (gs = -2) of the electron is predicted by the Dirac’s equation. The orbit g factors of electron, muon and tau are gL = gEC = -1 from the EC g factor (gEC = -1) without the contribution of the LC g factor (gLC = -1). The spin g factors of the elementary fermions are calculated from the equation of gs = gEC + gLC + gCC where gEC = EC/|EC|, gLC = LC/|LC| and gCC = CC/|CC|. For example, the spin g factors of the neutrinos and dark matters are gs = -1. The spin g factors of the u and d quarks are gs = 0 and gs = -2, respectively. The g factor problem of neutrinos with the non-zero LC charges are solved by the LC Coulomb force of Fc(LC) ≈0. It is, for the first time, proposed that the binary motion (fluctuations) of the mEC and mLC masses for the electron, muon and tau leptons make the anomalous g factor. This binary motion could be originated from the virtual particle processes including the photons. Also, the weak force (beta) decay is closely related to the binary motion of the mEC and mLC for the electron, muon and tau leptons.
COMMUNICATION | doi:10.20944/preprints202203.0152.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: SPME; CBS-MS; brain tumors; lipidomics
Online: 10 March 2022 (14:16:39 CET)
Brain tumors are neoplasms with one of the highest mortality rates. Therefore, the availability of methods that allow the quick and effective diagnosis of brain tumors and selection of appropriate treatments is of critical importance for patient outcomes. In this study, coated blade spray-mass spectrometry (CBS-MS), which combines the features of microextraction and fast ionization methods, is applied for the analysis of brain tumors. In this approach, a sword-shaped probe is coated with a sorptive material to enable the extraction of analytes from biological samples. The analytes are then desorbed using only a few microliters of solvent, followed by the insertion of the CBS device into the interface on the mass spectrometer source. The results of this proof-of-concept experiment confirmed that CBS coupled to high-resolution mass spectrometry (HRMS) enables the rapid differentiation of two histologically different lesions: meningiomas and gliomas. Moreover, quantitative CBS-HRMS/MS analysis of carnitine, the endogenous compound, previously identified as discriminating metabolite showed good reproducibility with the variation below 10% when using a standard addition calibration strategy and deuterated internal standards for correction. The resultant data show that the proposed CBS-MS technique can be useful for on-site qualitative and quantitative assessments of brain tumor metabolite profiles.
ARTICLE | doi:10.20944/preprints202010.0450.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Multiple Sclerosis; MS; Disparities; Minority populations
Online: 22 October 2020 (09:03:44 CEST)
Multiple Sclerosis (MS) is a progressive neurodegenerative disease that affects more than 2 million people worldwide. Increasing knowledge about MS in different populations has advanced our understanding of disease epidemiology and variation in the natural history of MS among White and minority populations. In addition to differences in incidence, African American (AA) and Hispanic patients have greater disease burden and disability in earlier stages of disease compared to White patients. To further characterize MS in AA and Hispanic populations, we conducted a retrospective chart analysis of 112 patients treated at an MS center in Houston, Texas. Here, we describe differences in clinical presentation, MRI findings, treatment regimens, disability progression, and relapse rate. We found that patients who were evaluated by a neurologist at symptom onset had significantly decreased odds of greater disability [defined as Expanded Disability Status Scale (EDSS) > 4.5] at last presentation compared to patients who were not evaluated by a neurologist (OR: 0.04, 95% CI: 0.16-0.9). We also found that active smokers had significantly increased odds of greater disability both at diagnosis and at last clinical encounter compared to nonsmokers (OR: 2.44, 95% CI: 1.10-7.10, OR= 2.44, 95% CI: 1.35-6.12, p= 0.01, respectively). Assessment of the degree of brain atrophy and progression over time along with enumeration of T1, T2, and gadolinium-enhancing brain lesions did not reveal differences across groups.
ARTICLE | doi:10.20944/preprints202109.0071.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: lysophospholipids; lysophosphatidic acids; cardiovascular diseases; HPLC-MS/MS; rodent models; pulmonary hypertension; chronic heart failure; hypertension
Online: 3 September 2021 (15:19:54 CEST)
Cardiovascular diseases (CVD) are the leading cause of premature death and disability in humans. Increasing data suggest that CVD is closely related to lipid metabolism and signaling. This study aimed to assess whether circulating lysophospholipids (LPL), lysophosphatidic acids (LPA) and monoacylglycerols (MAG) may be considered as biomarkers of CVD. For this objective, the evolution of the plasma levels of 22 compounds (13 LPL, 6 LPA and 3 MAG) was monitored by liquid chromatography coupled with tandem mass spectrometry (HPLC/MS²) in different rat models of CVD, i.e. angiotensin-II-induced hypertension (HTN), ischemic chronic heart failure (CHF) and sugen/hypoxia(SuHx)-induced pulmonary hypertension (PH). On one hand, there was modest changes on the monitored compounds in HTN (LPA 16:0, 18:1 and 20:4), LPC 16:1) and CHF (LPA 16:0, LPC 18:1 and LPE 16:0 and 18:0) models compared to control rats but these changes were no longer significant after correction for multiple testing. On the other hand, PH was associated with important changes in plasma LPA with a significant increase in the 16:0, 18:1, 18:2, 20:4 and 22:6 species. A deleterious impact of LPA was confirmed on isolated human pulmonary smooth muscle cells with an increase in their proliferation. This study demonstrates that circulating LPA species are increased in rats with PH and may contribute to the pathophysiology of this disease. Additional experiments are needed to assess whether the modulation of LPA signaling in PH may be of interest.
ARTICLE | doi:10.20944/preprints201701.0036.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Acer truncatum leaves; ultrasonic-assisted extraction; response surface methodology; phenolics; antioxidant activity; UPLC-QTOF-MS/MS
Online: 9 January 2017 (04:16:01 CET)
This study was designed for the first time to improve phenolic yield and antioxidant activity of ultrasonic-assisted extraction from Acer truncatum leaves (ATL) using response surface methodology, and phenolic composition in ATL extracted under the optimized condition were characterized by UPLC-QTOF-MS/MS. Solvent and extraction time were selected based on preliminary experiments, and a four-factors-three-levels central composite design was conducted to optimize solvent concentration (X1), material-to-liquid ratio (X2), ultrasonic temperature (X3) and power (X4) for an optimal total phenol yield (Y1) and DPPH• antioxidant activity (Y2). The results showed that the optimal combination was ethanol: water (v:v) 66.21%, material-to-liquid ratio 1:15.31 g/mL, ultrasonic temperature 60 °C, power 267.30 W, and time 30 min with three extractions, giving a maximal total phenol yield of 7593.62 mg gallic acid equivalent /100 g d.w. and a maximal DPPH• antioxidant activity of 74241.61 μmol Trolox equivalent/100 g d.w.. Furthermore, 22 phenolics were first identified in ATL extract obtained under the optimized conditions, indicating that gallates, gallotannins, quercetin, myricetin and chlorogenic acid derivatives were the main phenolic composition in ATL. What’s more, a gallotannins pathway existing in ATL from gallic acid to penta-O-galloyl-glucoside was interpreted. All these results provided practical information aiming at full utilization of phenolics in ATL, together with fundamental knowledge for further research.
REVIEW | doi:10.20944/preprints202307.1785.v1
Subject: Biology And Life Sciences, Food Science And Technology Keywords: in vivo; aroma release; aroma perception; dynamic methods; nosespace; DIMS; TI; TDS; TCATA; APCI-MS; PTR-MS
Online: 26 July 2023 (11:11:42 CEST)
Perception of flavor is a dynamic process during which the concentration of aroma molecules at the olfactory epithelium varies with time as they are released progressively from the food in the mouth during consumption. The release kinetics depends on the food matrix itself, but also on food oral processing, such as mastication behavior and food bolus formation with saliva, for which huge inter-individual variations exist due to physiological differences. Sensory methods, such as time-intensity (TI), or the more recent methods temporal dominance of sensations (TDS) and temporal check-all-that-apply (TCATA), are used to account for the dynamic and time-related aspects of flavor perception. Direct injection mass spectrometry (DIMS) techniques that measure in real-time aroma compounds directly in the nose (nosespace), aimed at obtaining data that reflect the pattern of aroma release in real-time during food consumption, supposed to be representative of perception, have been developed since 25 years. Examples obtained with MS operated in chemical ionization mode at atmospheric or sub-atmospheric pressure (atmospheric pressure chemical ionization APCI or proton transfer reaction PTR) will be given, with emphases on studies conducted with simultaneous dynamic sensory evaluation. Inter-individual variations in terms of aroma release and their relevance for understanding flavor perception will be discussed, as well as evidenced cross-modal interactions.
ARTICLE | doi:10.20944/preprints202311.1436.v1
Subject: Environmental And Earth Sciences, Pollution Keywords: Gadolinium; Contrast Agent; ICP-MS; Chemical Stability
Online: 22 November 2023 (14:17:12 CET)
Gadolinium-based contrast agents (GBCA) are complexes, highly stable in vivo, used in Magnetic Resonance Imaging (MRI), administered in patients and then eliminated via renal, passing through wastewater treatment plants (WWTP) before being discarded in the receiving medium, without apparent removal. In this study, it was studied if different exposure periods to several environmental parameters (solar radiation, different salinities, temperatures and pH) will influence the stability of these complexes, namely, the Gd-DOTA. Gd-DOTA solutions were processed in a seaFAST-pico saline matrix pre-concentration and elimination system and Gd concentrations were determined by ICP-MS. Results showed that the complex remained stable in fresh, brackish and saline water environments, even when exposed to extreme temperatures (40ºC) or slightly acidic to basic conditions (6-10), for an exposure period of 96h. A small increase in the free Gd concentration was observed after 18 days when exposed to pH<4, in all tested salinities (0, 18 and 36 PSU), with a degradation increase of up to 29%, after 5 weeks of exposure in freshwater. When exposed to direct solar radiation a low Gd-DOTA degradation (4%) was observed after 24h at salinity 18 PSU and remained constant until the end of the exposure period (96h), while the remaining salinities showed negligible values.
ARTICLE | doi:10.20944/preprints202311.1368.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: Empetrum rubrum; Antioxidant; Antifungal activity; HPLC-MS
Online: 22 November 2023 (03:43:26 CET)
In searching for compounds with antioxidant and antifungal activity, our study focused on the subshrub species Empetrum rubrum Vahl ex Willd. (Ericaceae), commonly known as Brecillo or Murtilla de Magallanes. We measured the antioxidant activity of its methanolic extract (MEE) obtained from the aerial parts (leaves and stems). The antioxidant activity of MEE was evaluated in vitro by 2,2-Diphenyl-1-picrylhydrazyl (DPPH) free radical and 2,2′-Azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) cationic radical. Results were expressed in gallic acid and Trolox equivalents for DPPH and ABTS assays, respectively. The antioxidant activities, for the DPPH and ABTS assays, were also calculated as an inhibitory concentration of extract needed to inhibit 50% of the absorbance (IC50 value). The results of IC50 values measured by the DPPH and ABTS methods were 0.4145 mg mL-1 and 0.1081 mg mL-1, respectively. In relation to the antioxidant activity, the total phenolic content (TPC) in MEE was determined by the Folin-Ciocalteu method, and the presence of secondary metabolites groups, including phenolic compounds, was determined by using different standardized test procedures. Phenolic compounds contained in leaves, stems, and fruits of E. rubrum were determined qualitatively by means of high-performance liquid chromatography coupled with mass spectrometry (HPLC-MS) analysis. The antifungal activity of MEE obtained from aerial parts of E. rubrum was tested against Rhizoctonia solani. In vitro, mycelial growth of this fungus was reduced from 90% to 100% in the presence of MEE.
ARTICLE | doi:10.20944/preprints202310.1160.v2
Subject: Chemistry And Materials Science, Food Chemistry Keywords: VOCs; PTR-MS; Adsorption; Photocatalysis; Cooking emissions
Online: 15 November 2023 (16:31:41 CET)
Volatile organic compounds (VOCs) are molecules present in our everyday life, and they can be positive, such as in the formation of odour and food flavour, or harmful for environment and humans, and the research is focusing on limiting their emissions. Various methods have been used to achieve this purpose. Firstly, we review three main degradation methods: activated carbon, photocatalysis and a synergetic system. We provide a general overview of the operative conditions and report the possibility of VOC abatement during cooking. Within the literature, none of these systems has ever been tested in presence of complex matrices, such as during a cooking process. The aim of this study is to compare the three methods in order to understand the behaviour of filter systems in the case of realistically complex gas mixtures. Proton Transfer Reaction - mass spectrometry (PTR-MS) has been used as real-time monitoring of volatilome. Since VOC emissions are highly dependent on the composition of the food cooked, we evaluated the degradation capacity of the three systems for different burger types (meat, greens and fish). We demonstrate pros and cons of the photocatalysis and adsorption and how a combined approach can mitigate the drawbacks of photocatalysis.
ARTICLE | doi:10.20944/preprints202309.2130.v1
Subject: Biology And Life Sciences, Life Sciences Keywords: Artemisia; essential oil; GC-MS; AChE; BChE
Online: 30 September 2023 (08:17:03 CEST)
The essential oil (EO) of Artemisia plants contains a large number of bioactive compounds that are widely used. The aim of this study was to analyse the chemical composition of EOs of six Arte-misia plants collected in Croatia and to test their cholinesterase inhibitory potential. GC-MS analysis of EO of A. absinthium showed that the dominant compounds are cis-sabinyl acetate and cis-epoxy-ocimene; in EO of A. abrotanum it is borneol; in EO of A. annua it is artemisia ketone, camphor, and 1,8-cineole; in EO of A. arborescens it is camphor and chamazulene; in EO of A. verlotiorum it is cis-thujone, 1,8-cineole, and trans-thujone; in EO of A. vulgaris, it is trans-thujone and trans-epoxy-ocimene. EO of the five studied Artemisia species from Croatia is rich in mono-terpenoid compounds (1,8-cineole, artemisia ketone, cis-thujone, trans-thujone, cis-epoxy-ocimene, camphor, borneol, and cis-sabinyl acetate). EO of A. arborescens is also rich in chamazulene. The results also showed that the tested EOs have moderate cholinesterase inhibi-tion potential, especially the EOs of A. annua, A. vulgaris, and A. abrotanum. This is the first anal-ysis of the chemical composition of the EOs of four Artemisia plants and the first analysis of cho-linesterase potential for plants collected in Croatia.
ARTICLE | doi:10.20944/preprints202306.1985.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: medicinal plant; bioactive molecules; terpenoids; GC-MS
Online: 28 June 2023 (09:54:10 CEST)
Lagenaria siceraria (Molina) Standley is a food and medicinal plant with a wide range of applica-tions including anti-proliferative, anti-fertility, anti-HIV and anti-cancerous. The current study investigated the phytochemical constituents of L. siceraria fruits using gas chromatog-raphy/mass spectrometry (GC-MS). GC-MS analysis of L. siceraria n-hexane fruits revealed five isoprenoids which were present in all investigated landraces, 1-Dodecene, 2,3-Dimethyldodecane, E-15-Heptadecenal, Eicosane and Tridecane, 6-propyl. Bioactive molecules with a lower carbon number on their chemical structure such as 1-Dodecene and 2,3-Dimethyldodecane with 12 and 14 carbon structures were recorded at a shorter retention rate range of 9.08-16.29 min over a lower relative peak area ranging from 1.09-6.97 %. While com-pounds with longer carbon chains ranging from 16-20 carbons (E-15-Heptadecenal, Eicosane and Tridecane, 6-propyl) had longer retention rate range of 13.42-18.00 mins over a higher relative peak area range of 2.25-11.41%. An agglomerative hierarchical cluster analysis grouped landrac-es into 5 clusters (I -V). Landraces were clustered according to their fruit and seed attributes, and isoprenoid units significant to each cluster. The majority of phytochemicals revealed were terpenoids, these are responsible for attracting pollinators, fruit growth, palatability and attrac-tive aromatic scents. This is the most comprehensive study on the n-hexane fruit phytochemical constituents of different L. siceraria landraces to date.
ARTICLE | doi:10.20944/preprints201911.0363.v1
Subject: Environmental And Earth Sciences, Atmospheric Science And Meteorology Keywords: physical properties; tem, icp-ms; elemental composition
Online: 28 November 2019 (12:05:34 CET)
This study was conducted in a laboratory-controlled environment aiming at studying the physical properties and elemental composition of coal combustion particles in a brazier. Particles were sampled ~1 m above the stove using a partector, where particles were collected on gold Transmission Electron Microscopy (TEM) grids and polycarbonate filters for TEM and inductively coupled plasma mass spectrometry (ICP-MS) analysis, respectively. Particles for elemental analysis collected on a 37 µm polycarbonate filters whereby a Gillian pump was used to draw in air. During sampling, a 2.5 µm cyclone was attached to the sampling cassette to isolate larger particles. The results have shown that combustion particles emitted during the early stage of combustion where single spherical particles with a diameter of around 450 nm. As the combustion progresses, the particle diameter gradually decreases and the morphology changes to accretion chain and fluffy bead structure for the flaming and char-burning phase, respectively.
ARTICLE | doi:10.20944/preprints201903.0152.v1
Subject: Biology And Life Sciences, Insect Science Keywords: Apis mellifera; GC-MS; larva; terpenoids; volatiles
Online: 14 March 2019 (08:59:13 CET)
(E)-β-ocimene was the only found volatile chemical emitted by whole, live worker larvae of Apis mellifera L. by sampling in the vapor phase. While in addition to (E)-β-ocimene, there is evidence for the existence of other volatiles; but the changes of their composition and contents remain unknown during larval development, as are their differences from larvae to larval food. This is the main purpose of the study. We investigated volatile components of worker larvae and larval food using solid phase dynamic extraction (SPDE) coupled with gas chromatography-mass spectrometry (GC-MS). Nine compounds were identified with certainty and six tentatively, consisting of terpenoids, aldehydes, hydrocarbons, ester and ketone. The contents of volatiles of the second-instar worker larvae differ greatly from larvae of other stages mainly attributable to terpenoids, which made the second-instar worker larvae had significantly higher amounts of overall volatiles. Larval food contained significantly higher amounts of aldehydes and hydrocarbons than the corresponding larvae from the fourth to fifth-instar. We discovered volatiles in worker larvae and their food which were never reported before; we also mastered the change of these volatiles’ contents during larval development.
ARTICLE | doi:10.20944/preprints201902.0218.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: Salvia officinalis, Essential oil, GC-MS, Sudan
Online: 25 February 2019 (08:50:48 CET)
Abstract: In this study the essential oils of Salvia officinalis growing in Sudan, were obtained by hydrodistillation and analyzed by Gas chromatography mass spectrometer, forty tow compounds were identified. The essential oil composition of S.officinalis found that it had many important compounds. The detected main compounds were oxygenated monoterpenes followed monohydrocarbone, squiterpenes and other compounds. The main essential oil constituents were α-terpineol (33.07%), camphor (11.57%), α-pinene (8.96%) camphene (5.09%) β-cymen (5.40 %) caryphyllene (3.76%) β-myrcene (3.65%) β-menth1-en-b-ol (3.45%) bomeol (3.38%) β-pinene (2.74%) Epiglobulol (2.59%) 1,8 Cineol (2.24%) and trans-β- terpinyl butanone(2.00% ).
ARTICLE | doi:10.20944/preprints201610.0090.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: Laminaria hyperborean; lipids; fatty acids; GC-MS
Online: 21 October 2016 (08:59:13 CEST)
A thorough analysis and comparison of the fatty acid profiles of stipe and blade from Laminaria hyperborea, a kelp species found in the northern Atlantic, is presented. Lipids were extracted and fractionated into neutral lipids, free fatty acids and polar lipids, then derivatized to fatty acid methyl esters prior to GC-MS analysis. A total of 42 fatty acids were identified and quantified, including the n-3 fatty acids α-linolenic acid, stearidonic acid and eicosapentaenoic acid. An n-6/n-3 ratio of 0.8:1 was found in blade and 3.5:1 in stipe, respectively. The ratios vary between the lipid fractions within stipe and blade, with the lowest ratio in the polar lipid fraction of blade. The fatty acid amounts are higher in blade than in stipe, and the highest amounts of n-3 fatty acids are found within the neutral lipid fractions. The amounts of polyunsaturated fatty acids are 3.4 times higher in blade than stipe. This study highlights the compositional differences between the lipid fractions of stipe and blade from L. hyperborea. The amount of polyunsaturated fatty acids, compared to saturated- and monounsaturated fatty acids, as well as the n-6/n-3-ratio, is known to influence human health. In the pharmaceutical, food, and feed industries this can be of importance for production and sale of different health products. Additionally, lipids are today among the unused by products of alginate production, exploiting this material for commercial interest should give both economical and environmental benefits.
ARTICLE | doi:10.20944/preprints202311.1375.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: HS-MS e-NOSE; packaging; prediction; shelf life
Online: 22 November 2023 (06:35:46 CET)
A rapid and efficient technique using an electronic nose based on a mass detector combined with headspace sampling (HS-SPME-MS e-nose) and chemometric tools was applied to classify beer samples between fresh and aged and between samples contained in aluminium cans or glass bottles, and to predict the shelf life of beer. The mass spectra obtained from the HS-SPME-MS e-nose contain information on the volatile compounds, recorded as the abundance of each ion at different mass-to-charge (m/z) ratios. The analysis was performed on 53 samples aged naturally for eleven months in the absence of light and with a controlled temperature of around 14° C +/- 0.5° C. Principal Component Analysis (PCA) was performed on the data, showing a grouping of samples between fresh and aged. Partial Least Square Discriminant Analysis (PLS-DA) allowed discriminating fresh from aged beers but was not able to discriminate samples packaged in aluminium cans or in glass bottles. Finally, Partial Least Square Regression (PLSR) was applied to build a prediction model and showed to be effective to predict beer shelf life.
ARTICLE | doi:10.20944/preprints202311.0659.v1
Subject: Public Health And Healthcare, Other Keywords: Low back pain (LBP); multiple sclerosis (MS); physiotherapy
Online: 9 November 2023 (14:51:37 CET)
Background. The purpose of the study was to evaluate the intensity and frequency of low back pain (LBP) in people with multiple sclerosis (PwMS) and the patient's knowledge of physiotherapeutic methods of combating. Methods. In this study, patients with confirmed multiple sclerosis were selected. The study was carried out using an original survey questionnaire and a numerical pain intensity scale (Visual Analogue Scale). PwMS were divided into 3 age groups: 18-30 years, 31-50 years, and over 50 years. Results. Ninety PwMS (68 women and 22 men) aged 18 to 60 years were included in the study. The mean duration of the disease was 9.5±4.9 years, and the mean EDSS was 3.5±1.6. Most of the patients had a relapse-remitting form. 68.9% of PwMS felt lower back pain (n = 62). The relationship tested was statistically significant (p=0.0000012), and the strength of the relationship was high (rc=0.695). The average level of low back pain among PwMS was 4.7 out of 10 on the VAS scale. The prevalence of LBP was higher in female patients (p<0.001), with a secondary progressive form (p<0.001) and with a longer duration of the disease (p=0.023). The most widely used methods of LBP therapy were kinesitherapy and manual therapy. Conclusions. LBP is common in multiple sclerosis. A female sex, a secondary progressive form of MS, and a longer duration of the disease increased the risk of LBP. It is important to implement properly planned physiotherapy activities and educate patients on how to combat LBP.
ARTICLE | doi:10.20944/preprints202305.0198.v1
Subject: Medicine And Pharmacology, Pediatrics, Perinatology And Child Health Keywords: gastric fluid; urine; metabolite; GC-MS; prematurity; survival
Online: 4 May 2023 (05:21:26 CEST)
Prediction of survival in very preterm infants is very important in terms of clinical medicine and parent counseling. In this prospective study involving 96 very preterm infants, we evaluated whether metabolomic analysis of gastric fluid and urine samples obtained soon after birth could predict survival on days of life (DOL) 3 and 15 as well as overall survival up to hospital discharge. Gas chromatography-mass spectrometry (GC-MS) profiling was used. Uni- and multivariate statistical analyses were carried out to evaluate significant metabolites and their prognostic value. Differences in several metabolites were identified between survivors and non-survivors at the time-points of the study. Binary logistic regression showed that certain metabolites in the gastric fluid including arabitol as well as succinic, erythronic and threonic acids was associated with DOL 15 and overall survival. Gastric glyceric acid was also associated with DOL 15 survival. Urine glyceric acid could predict survival on DOL 3 and overall survival. In conclusion, non-surviving preterm infants showed a different metabolic profile compared survivors showing a significant discrimination with the use of GC-MS-based gastric fluid and urine analysis. Results of this study support the usefulness of metabolomics in developing survival biomarkers in very preterm infants.
ARTICLE | doi:10.20944/preprints202304.0468.v1
Subject: Biology And Life Sciences, Agricultural Science And Agronomy Keywords: Bacillus; biocontrol; volatile organic compound; GC-MS; sporulation
Online: 18 April 2023 (03:28:47 CEST)
Magnaporthe oryzae Triticum (MoT) pathotype is the causal agent of wheat blast, which has caused significant economic losses and threatens wheat production in South America, Asia and Africa. Three bacterial strains from rice and wheat seeds (B. subtilis BTS-3, B. velezensis BTS-4, and B. velezensis BTLK6A) were used to explore the antifungal effects of volatile organic compounds (VOCs) of Bacillus spp. as a potential biocontrol mechanism against MoT. All bacterial treatments significantly inhibited both mycelial growth and sporulation of MoT in vitro. We found that this inhibition was caused by Bacillus VOCs in a dose-dependent manner. In addition, biocontrol assays using detached wheat leaves infected with MoT showed reduced leaf lesions and sporulation compared to the untreated control. VOCs from B. velezensis BTS-4 alone or a consortium (mixture of B. subtilis BTS-3, B. velezensis BTS-4, and B. velezensis BTLK6A) treatments consistently suppressed MoT in vitro and in vivo. Compared to the untreated control, VOCs from BTS-4 and Bacillus consortium reduced MoT lesions in vivo by 85% and 81.25%, respectively. A total of thirty-nine VOCs (from 9 different VOC groups) from 4 Bacillus treatments were identified by gas chromatography-mass spectrometry (GC-MS), of which 11 were produced in all Bacillus treatments. Alcohols, fatty acids, ketones, aldehydes, and S-containing compounds were detected in all four bacterial treatments. In vitro assays using pure VOCs revealed that hexanoic acid, 2-methylbutanoic acid, and phenylethyl alcohol are potential VOCs emitted by Bacillus spp. that are suppressive for MoT. The minimum inhibitory concentrations for MoT sporulation were 250 mM for phenylethyl alcohol and 500 mM for 2-methylbutanoic acid and hexanoic acid. Therefore, our results indicate that VOCs from Bacillus spp. are effective compounds to suppress the growth and sporulation of MoT. Understanding the MoT sporulation reduction mechanisms by Bacillus VOCs may provide novel options to manage the further spread of wheat blast by spores.
ARTICLE | doi:10.20944/preprints202111.0398.v1
Subject: Medicine And Pharmacology, Pharmacology And Toxicology Keywords: Aspergillus giganteus; Aspergillosis; Antagonism; Sarcin; ADMET; GC-MS
Online: 22 November 2021 (13:56:36 CET)
Fungal infections are more predominant in agricultural and clinical fields. Aspergillosis caused by Aspergillus fumigatus leads to respiratory failure in patients along with various illnesses. Due to the limitation of antifungal therapy and antifungal drugs, there is an emergence to develop efficient antifungal compounds from natural sources to cure and prevent fungal infections. The present study deals with the investigation of the mechanism of active compounds from our candidate agonist Aspergillus giganteus for aspergillosis. The integrity of treated Aspergillus fumigatus cell membrane and nuclear membrane was analyzed by determining the release of cellular materials. The antagonistic potential of antifungal compounds on the pathogen was confirmed by SEM analysis. The effective concentration of antifungal compounds (AFCs) was found to be 250µg/ml. The GC-MS profiling has revealed the bioactive metabolites responsible for the antagonistic nature of Aspergillus giganteus. The bioavailability and toxicological properties of pathogenesis related proteins have proved the efficiency of pharmacokinetic properties of selected compounds. Interaction of sarcin, thionin, chitinase and its derivatives from Aspergillus giganteus with the virulence proteins of UDP-N-acetylglucosamine pyrophosphorylase, N-myristoyl transferase and Chitinase have proved the druggable nature of the antifungal compounds.
ARTICLE | doi:10.20944/preprints202101.0410.v1
Subject: Medicine And Pharmacology, Immunology And Allergy Keywords: Elettaria cardamomum; GC-MS, compositions; antibacterial; antidiarrhoeal; antispasmodic
Online: 21 January 2021 (09:13:58 CET)
The present study examined the volatile composition and antimicrobial and gastrointestinal activity of the essential oils of Elettaria cardamomum (L.) Maton harvested in India (EC-I) and Guatemala (EC-G). Monoterpene were present in higher concentration in EC-I (83.24%) than in EC-G (73.03%), whereas sesquiterpenes were present in higher concentration in EC-G (18.35%) than in EC-I (9.27%). Minimum inhibitory concentrations (MICs) of 0.5 and 0.1 mg/mL were demonstrated against Pseudomonas aeruginosa in EC-I and EC-G, respectively, whereas MICs of 0.125 and 1 mg/mL were demonstrated against Escherichia coli in EC-I and EC-G, respectively. The treatment with control had the highest kill-time potential, whereas the treatment with oils had shorter kill-time. EC-I was found to be more potent in the castor oil-induced diarrhoea model than EC-G. At 100 and 200 mg/kg, EC-I exhibited 40% and 80% protection, respectively, and EC-G exhibited 20% and 60% protection, respectively, in mice, whereas loperamide (positive control) exhibited 100% protection. In the in vitro experiments, EC-I inhibited both carbachol (CCh, 1 µM) and high K+ (80 mM)-induced contractions at significantly lower concentrations than EC-G. Thus, EC-I significantly inhibited P. aeruginosa and E. coli and exhibited more potent antidiarrheal and antispasmodic effects than EC-G.
ARTICLE | doi:10.20944/preprints202009.0317.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: ICP-MS; trace elements; wine; Nizza; Barbera; authentication
Online: 14 September 2020 (00:49:48 CEST)
Barbera d'Asti - including Barbera d'Asti superiore - and Nizza are two DOCG (Denominazione di Origine Controllata e Garantita) wines produced in Piemonte (Italy) from Barbera grape variety. Differences among them arise in the production specifications in terms of purity, ageing and zone of production, in particular with concern to Nizza, which has more stringent rules and can therefore be considered as the one with the highest market value, with even three-fold more average prices. To guarantee producers and consumers, authentication methods must be developed in order to distinguish among the different wines. As the production zones totally overlap, it is important to verify whether the distinction is possible or not according to metals content, or whether chemical markers more linked to winemaking are needed. In this work, Inductively Coupled Plasma (ICP) elemental analysis and multivariate data analysis are used to study the authentication and traceability of samples from the three designations of 2015 vintage. The results show that, as far as elemental distribution in wine is concerned, work in the cellar, rather than geographic provenance, is crucial for the possibility of distinction.
ARTICLE | doi:10.20944/preprints202008.0563.v1
Subject: Environmental And Earth Sciences, Pollution Keywords: Lagos lagoon; plastics; FTIR; pyrolysis GC-MS; sedimentology
Online: 26 August 2020 (06:30:56 CEST)
Microplastics are a fast emerging group of contaminants. Their worldwide occurrence in water, sediment, and aquatic fauna raises questions and concerns as to their probable effects on aquatic life and ecology. This study investigates for the first time presence, abundance, and types of microplastics in water and sediment from a lagoon bordering the large urban agglomeration of Lagos in Nigeria, and renders additional information about grain size and sediment composition. Water and sediment samples were collected from four locations in the Lagos lagoon and a tributary. The abundance and distribution of microplastics in four range classes were determined for the sampled locations. Plastic particles were counted using digital microscopy, and identified with FTIR and pyrolysis GC-MS. The abundance of microplastics ranged from 310-2319 microplastic particles/kg in sediment, and 139-303 particles/m3 in water. The large discrepancy in the sediments can be explained by sediment characteristics as more microplastics were detected in the fine-grained sediments of Makoko. Fibres were the predominant shape found in all samples followed by fragments and few films whereas spheres were missing. Fibres were more abundant in water (92.6 %) than in sediments (32.5 %) while more fragments and foils occurred in sediments. The most commonly used polymers polypropylene and polyethylene were also the most detected ones in both matrices. Compared to other studies in Nigeria, our findings especially in the coarser sediments were lower while the fine-grained site revealed similar results.
ARTICLE | doi:10.20944/preprints202007.0687.v1
Subject: Chemistry And Materials Science, Applied Chemistry Keywords: Gamma-ray, Mutant, Rose, Volatile compounds, GC-MS
Online: 29 July 2020 (09:46:55 CEST)
Roses are one of the most important floricultural crops, and their essential oils have long been used for cosmetics and aromatherapy. We investigated the volatile compound compositions of 12 flower-color mutant variants and their original cultivars. Twelve rose mutant genotypes were developed by treatment with 70 Gy of 60Co gamma irradiation of six commercial rose cultivars. Essential oils from the flowers of the 18 genotypes were analyzed by gas chromatography–mass spectrometry. Seventy-seven volatile compounds were detected, which were categorized into five classes: hydrocarbons, terpenoids, alcohols, esters, and others. Hydrocarbons, alcohols, and esters were major components in all rose flowers. The mutant genotypes CR-S8 and CR-S9 showed higher contents of hydrocarbons than the original cultivar. In addition, CR-S1, CR-S3, and CR-S4 mutant genotypes showed higher ester contents than their original cultivar. Nonacosane, 2-methylhexacosane, and 2-methyltricosane were major volatile compounds among all genotypes. Hierarchical cluster analysis of the rose genotypes gave four groups according to grouping among the 77 volatile compounds. These findings will be useful for the selection of rose genotypes with improved volatile compounds.
ARTICLE | doi:10.20944/preprints201809.0122.v1
Subject: Chemistry And Materials Science, Organic Chemistry Keywords: spatial; age-related; phytochemical; bamboo; rhizome; GC-MS
Online: 7 September 2018 (03:01:53 CEST)
This study was designed to assess variation of possible phytochemical compounds in the ethanolic extracts of Gigantochloa scortechinii rhizome. Destructive sampling was done by using selective random sampling method on four consecutive rhizomes from healthy clumps and was conducted at two natural forests and one secondary forest (planted). Homogenized sample were extracted using solvent extraction (70% ethanol) method. Ethanolic extracts of G. scortechinii rhizome were qualitatively analyzed using GC/MS GC2010 Plus, Shimadzu to determine the composition of phytochemical compounds and identified using FFNSC 1.3, NIST11, PMW_tox2, and Wiley229 spectral library. A qualitative variation was observed with a total of 56 compounds were identified and differentiated between study site and rhizome age. Results revealed that G. scortechinii rhizome contains various phytochemical compounds with potential as a plant of phytopharmaceutical importance. This is the first finding on the spatial and age-related effects of phytochemical compounds in a consecutive rhizome and of G. scortechinii rhizome specifically.
ARTICLE | doi:10.20944/preprints201806.0142.v1
Subject: Chemistry And Materials Science, Analytical Chemistry Keywords: gluten-free foods, fatty acids, GC-MS, celiac
Online: 8 June 2018 (16:20:20 CEST)
The aim of this study (first analytical approach) was to obtain data on the fatty acid composition of gluten-free foods (bakery products) for celiac people. The study included 35 different products (snacks, biscuits, bakery products, pasta, flours, etc.) from several manufacturers. After extraction and esterification, the fatty acid content was determined by GC-MS. The monounsaturated fatty acids (MUFAs) are the major constitutes (57%) of the fatty acids pool followed by saturated fatty acids (SFAs) (30%) and polyunsaturated fatty acid (13%). Only fifteen, of the thirty-five gluten free samples analyzed, provide adequate energy intake, while in eleven samples, saturated fatty acids take more energy than that recommended by EFSA. It has emerged that local producers generally use the finest raw materials (olive oil, etc.) compared to the industries which, as has been pointed out, in many cases use palm and palm kernel oils although gluten free commercial products are high added value foods, expensive and intended for a particularly sensitive public.
ARTICLE | doi:10.20944/preprints202002.0460.v1
Subject: Engineering, Electrical And Electronic Engineering Keywords: digital metamaterial; liquid crystal (LC); coding particle; beam steering; RCS reduction; beam shaping
Online: 29 February 2020 (09:32:31 CET)
This paper presents a multifunctional reflective digital metasurface of arbitrary base based on voltage tunable liquid crystal (LC). The reflective digital metamaterial can be multiplexed for different desirable functions by properly biasing the LC for different code patterns. Simulation results of three significant functions, beam steering with a steering elevation angle 27° at 75 GHz, RCS reduction of at least 15dB along the incident direction, and beam shaping with different beam shapes have been presented to prove the concept.
ARTICLE | doi:10.20944/preprints201805.0344.v1
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: LC-QQQ; liquid chromatography; triple quadrupole; vitamin D; 25(OH)D; plants; algae
Online: 24 May 2018 (09:27:21 CEST)
Vitamin D has previously been quantified in some plants and algae, particularly in leaves of the Solanaceae family. We measured the vitamin D content of Australian native food plants and Australian-grown edible seaweed. Using liquid chromatography with triple quadrupole mass spectrometry, 13 samples (including leaf, fruit and seed) were analysed in duplicate for vitamin D2, vitamin D3, 25-hydroxyvitamin D2 and 25-hydroxyvitamin D3. Five samples contained vitamin D2: raw wattleseed (Acacia victoriae) (0.03 µg/100 g dry weight (DW)); fresh and dried lemon myrtle (Backhousia citriodora) leaves (0.03 and 0.24 µg/100 g DW, respectively); dried leaves and berries of Tasmanian mountain pepper (Tasmannia lanceolata) (0.67 and 0.05 µg/100 g DW, respectively). Fresh kombu (Lessonia corrugata) contained vitamin D3 (0.01 µg/100 g DW). Detected amounts were low; however, it is possible that exposure to ultraviolet radiation may increase the vitamin D content of plants and algae if vitamin D precursors are present.
ARTICLE | doi:10.20944/preprints202311.1016.v1
Subject: Chemistry And Materials Science, Food Chemistry Keywords: Pyrolysis; Sucrose; Histidine; GC-MS analysis; Immune cells; Apoptosis
Online: 15 November 2023 (13:59:27 CET)
High-temperature cooking process like frying, baking, smoking, or drying can induce chemical transformations in conventional food ingredients, causing deteriorative modifications. These reactions, including hydrolytic, oxidative, and thermal changes, are a common occurrence and can result in alterations to the food's chemical composition. In this study, a combination of sucrose and histidine (Su-Hi) was transformed through a process of charring or pyrolysis. The GC-MS profiling study showed that when sucrose and histidine (Su-Hi) are exposed to high temperatures (≈240°C), they produce carbonyl and aromatic compounds including beta-D-Glucopyranose, 1,6-anhydro (10.11 %), 2-Butanone, 4,4-dimethoxy- (12.89 %), 2(1H)-Quinolinone-hydrazine (5.73%), Benzenamine (6.35%), 2,5-Pyrrolidinedione, 1-[(3,4-dimethylbenzoyl)oxy]- (5.82%), Benzene-(1-ethyl-1-propenyl) (5.62%), and 4-Pyridinamine-2,6-dimethyl (5.52%). The compounds mentioned have the ability to permeate the cell membrane and contribute to the development of cell death by necrosis in human immune cells. The evidence available suggests that a specific set of pyrolytic compounds may pose a risk to immune cells. This investigation reveals the complex relationship between high-temperature cooking-induced transformations, compound permeation inside the cells, and downstream cellular responses, emphasizing the significance of considering the broader health implications of food chemical contaminants.
ARTICLE | doi:10.20944/preprints202310.1800.v1
Subject: Biology And Life Sciences, Plant Sciences Keywords: essential oil; GC-MS analysis; spice; supercritical fluid extraction
Online: 27 October 2023 (12:04:19 CEST)
Cambodian spices Amomum kravanh, Citrus hystrix and Piper nigrum 'Kampot' have long history of seasoning of food products. In this study, essential oils (EOs) and supercritical CO2 extracts from all three species have been analyzed using GC-MS with two columns of different polarity, whereas EO and CO2 extract from P. nigrum fruits and CO2 extract from the peel of C. hystrix have been isolated and analyzed for the first time. The results showed that A. kravanh EO contained mostly eucalyptol (78.8/ 72.6 %), while CO2 extract was rich in oleic acid (29.26 %) and tricosane (14.74 %). C. hystrix EO was rich in β-pinene (29.95/29.45 %), followed by D-limonene (24.54/23.24 %) and sabinene (9.94/10.23 %). β-pinene (30.2/28.9 %), D-limonene (23.99/23.74 %) and sabinene (13.36/19.55 %) were also predominant in the CO2 extracts. β-Caryophyllene was the main constituent of both EO and CO2 extract from P. nigrum 'Kampot' with contents ranging from 37.84 to 55.84 %, followed by 3-carene (from 7.18 to 18.72 %). Such findings suggest that supercritical CO2 can potentially be used for extraction of all three Cambodian spices. Nevertheless, further research determining the most efficient extraction parameters will be needed before its application in the spice processing practice.
ARTICLE | doi:10.20944/preprints202309.0300.v1
Subject: Chemistry And Materials Science, Biomaterials Keywords: Zn–B–PLGA biocomposite; DLS; SEM; DoE; UHPLC/MS
Online: 5 September 2023 (10:03:29 CEST)
Our concern was to obtain a biocomposite material with improved properties of the constituent materials (poly(lactic- co-glycolic acid) (PLGA) and zinc–boron (Zn–B) complex) in accordance with the novelties in the field of delivery systems for therapeutic agents which lately redefine the importance of biopolymer nanocomposites with PLGA (biodegradable composites). The advantages of such a biomaterial target the health system, being easy to obtain, through a cost-effective method. The water/oil/water double emulsion method also allows the adjustment of the synthesis parameters, to maximize the degree of Zn–B complex encapsulation. The morphological aspects of the samples (size, shape, porosity) were established by scanning electron microscopy (SEM). Particle size distribution (by volume and by number) was determined by direct light scattering (DLS). For all the synthesized materials, the observed morphology was typical for PLGA, spherical one. The particle size distribution showed that depending on the synthesis conditions, the particles can be obtained with diameters between 10–450 nm range and the value of the zeta potential (ZP) shows that the particles have electronegative surface charge, which offers a favorable perspective on the phenomena of aggregation, flocculation, dispersion. It was observed, applying the design of experiments (DoE), that the size of the particles increased with increasing amounts of PLGA and polyvinyl alcohol (PVA) in the formulation, while ZP increased with higher PLGA and smaller PVA. The encapsulation efficiency was determined by ultra-high performance liquid chromatography/mass spectrometry (UHPLC/MS).