REVIEW | doi:10.20944/preprints202205.0340.v1
Subject: Life Sciences, Molecular Biology Keywords: herbivore-associated elicitors; plant defense; secondary metabolites; signaling metabolites; pattern recognition receptors
Online: 25 May 2022 (03:53:53 CEST)
Insect herbivores have a wide range of life cycles and feeding habits, making them extremely diverse. With their host plants, they form close relationships and suppress their defense mecha-nisms. Molecular elicitors are the key bio-elements in detection and recognition of attacking enemies in tissue consumption. Insect oral secretion, frass, and fluid of egg deposition contain bio-logical active molecules called herbivore-associated elicitors (HAEs) are recognized by pattern recognition receptors (PRRs). However, in insect herbivores, little is known about the molecular basis of signal transduction and regulation of plant resistance. Many plants distinguish insect feeding from wounding by HAEs presenting in their oral secretions (OS) and induce local and systemic responses against arthropod feeding. PRRs perceive HAEs in the oral secretion of cater-pillars in a species-specific manner to elicit exclusive defense responses. HAEs-PRRs interactions induce plant resistance by reprogramming plant metabolism and transcriptional machinery. Quantitative, timely, and coordinated plant response initiate early signalling events including Ca+2, reactive oxygen species (ROS) and mitogen-activated protein kinases (MAPKs). We have discussed how early signalling cascades converge into the accumulation of phytohormones that regulate down-stream special metabolites against herbivores. In this review, we have drawn a hypothetical model of PPRs-HAEs mediated induced responses in plants and discussed how PRRs-HAEs interactions based on molecular mechanism that elicit short- and long-term induced defenses in plants. The identification of plant target insect herbivore PRRs-HAEs interactions will help to explore the fundamental molecular mechanisms of host manipulation and may generate prospects to develop novel pest resistance strategies.
ARTICLE | doi:10.20944/preprints202208.0436.v1
Online: 25 August 2022 (13:21:39 CEST)
Indole and indole-3-lactate are known dominant microbial tryptophan catabolites (MICT). In obesity, the fecal indole concentration corresponds to the normal one, and that of indole-3-lactate significantly decreases along with other MICT, while it increases in blood plasma. During the analysis of the «enzymatic landscape» of the intestinal microbiota we find an almost twofold increase in the correlation between the concentrations of fecal MICT and the «enzymatic landscape», with indole-3-lactate having the closest relationships with the “enzymatic landscape” of all MICT. Here, we report statistically significant correlations of indole-3-lactate and the gut microbial enzymes for fructose, amino sugars, nucleotides, polyamines metabolism, and sulfoglycolysis. We also demonstrate that indole-3-lactate producing microbiota representatives increase three-fold in obesity. The phenotype of the microbiotic population is thus represented by completely different genera and species of microorganisms in obese individuals compared to healthy donors.
ARTICLE | doi:10.20944/preprints202105.0106.v1
Subject: Chemistry, Medicinal Chemistry Keywords: ecdysterone; metabolites; excretion profile; urinary pharmacokinetics
Online: 6 May 2021 (15:20:04 CEST)
Ecdysterone is a phytosteroid widely discussed for its various pharmacological, growth-promoting and anabolic effects mediated by activation of estrogen receptor beta (ERbeta). Performance-enhancement in sports was demonstrated recently, and ecdysterone was consequently included in the Monitoring Program to detect potential patterns of misuse in sport. Only few studies on the pharmacokinetics of ecdysterone in humans have been reported so far. In this study, post-administration urines in twelve volunteers (single dose of 50 mg of ecdysterone) were analyzed using dilute-and-inject liquid chromatography-tandem mass spectrometry. Identification and quantitation of ecdysterone and of two metabolites, 14-deoxy ecdysterone and 14-deoxy poststerone was achieved. Ecdysterone was the most abundant analyte present in post-administration urines, detected for more than 2 days with a maximum concentration (Cmax) in the 2.8-8.5 h urines (Cmax = 4.4-30.0 µg/mL). The metabolites 14-deoxy ecdysterone and 14-deoxy poststerone were detected later reaching the maximum concentrations at 8.5-39.5 h (Cmax = 0.1-6.0 µg/mL) and 23.3-41.3 h (Cmax = 0.1-1.5 µg/mL), respectively. Cumulative urinary excretion yielded average values of 18%, 2.3% and 1.5% for ecdysterone, 14-deoxy ecdysterone and 14-deoxy poststerone, respectively. Ecdysterone and 14-deoxy ecdysterone were excreted following first order kinetics with half-lives calculated with three hours, while pharmacokinetics of 14-deoxy poststerone needs further evaluation.
ARTICLE | doi:10.20944/preprints202102.0249.v1
Subject: Biology, Anatomy & Morphology Keywords: spontaneous plants; metabolites; insecticidal; identification; quantification
Online: 10 February 2021 (10:12:15 CET)
Spontaneous plants metabolites are more widespread for their properties and biological functions. Also, natural products have reminded diverse scientists to take a delight in their medical and insecticidal applications linked to the environmental. A variety of metabolites have a defensive function for the plants. Thus, three spontaneous plants: Caroxylon imbricatum, Tetraena alba and Cotula cinerea collected from two ecotypes and analyzed by two known conventional methods:Gas Chromatography‐Mass Spectrometry GC QTOF(quadrupole time of flight )_MS and Liquid Chromatography-Mass spectrometry LCQTOF(quadrupole time of flight )_MS. The investigation conducted out on the identification and quantification of metabolites revealed the main metabolites which have biological activities as a part of an alternative to synthetic insecticides. The chemical study showed the presence of N-Butylbenzensulfonamide and Sulfoxycaprylicacid in the three plants. N-Carboxy-methionineresidue, Butanoicacid and Valine were found in those of Cotula cinerea and Caroxylon imbricatum (Forssk.). Artomunoxanthentrione, Glycoaldehyde, Indoline, ,Benzensulfonamide and Oxoproline were detected in extracts of Caroxylon imbricatum (Forssk.) and Tetraena alba (L.f.) In addition, Pyrroline is the only compound common in Cotula cinerea and Tetraena alba (L.f.).
REVIEW | doi:10.20944/preprints202005.0295.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: coronaviruses; plants metabolites; polyphenols; antiviral-effect
Online: 18 May 2020 (04:09:48 CEST)
Coronaviruses such as SARS (severe acute respiratory syndrome), MERS (Middle East respiratory syndrome), and newly emerged SARS-CoV-2, also called 2019-nCoV and COVID 19, have caused worldwide outbreaks in different time periods. There are many studies about chemical and natural drugs to treat these coronaviruses by inhibiting their proteases or their protein receptors through binding to amino acid residues. Plants secondary and primary metabolites are considered as potential drugs to inhibit various types of coronaviruses. IC50 value (the concentration in which there is 50% loss in enzyme activity) and molecular docking score and binding energy are parameters to understand the metabolites ability to inhibit the specific virus. In this study we did review on more than 110 papers on plant metabolites effect on different coronaviruses. Secondary plant metabolites such as polyphenols (flavonoids, coumarins, stilbenes), alkaloids, terpenoids, organosulfur compounds saponins, saikosaponins, lectins, essential oils, nicotianamine and primary metabolites such as vitamins.
ARTICLE | doi:10.20944/preprints201808.0328.v1
Subject: Chemistry, Applied Chemistry Keywords: application; organochlorine; pesticides; metabolites; homesteads; soils
Online: 18 August 2018 (07:53:56 CEST)
The continued application of organochlorine pesticides (OCPs) in indoor residual spraying has posed significant threat to human health in Northern part of South Africa, despite its ban. In this study, we investigated the occurrence and spatial distribution of DDTs and its metabolites in surface soil (30 samples) collected in and around the spray homesteads; demarcated into three concentric zones A, B, C in Tshilamusi Vhembe district, South Africa. DDTs were the most abundant of all the OCPs chemicals found in soil samples. The concentrations of DDT range from 12.19 to 65.69 µg/kg, with the highest occurring at zone A which is the zone of application. DDTs and all its metabolites considered in this study were found in appreciable concentrations in soil of Zones B and C, far from spray sites. The results showed a strong correlation between distance and concentration levels of DDTs and its metabolites. However, there is a need for proper monitoring of OCPs chemicals in other environmental matrices as well as relevant agencies enforcing strict adherence to regulations on consumption of OCPs.
ARTICLE | doi:10.20944/preprints201806.0410.v1
Subject: Medicine & Pharmacology, Nutrition Keywords: spices; polyphenol; phenolic acids; metabolites; nutrikinetics
Online: 26 June 2018 (11:04:51 CEST)
Spices rich in polyphenols are metabolized to a convergent group of phenolic acids. We conducted a dose-exposure nutrikinetic study to investigate associations between mixed spices intake and plasma concentrations of selected, unconjugated phenolic acids. In a randomized crossover study, 20 Chinese males consumed a curry meal containing 0 g, 6 g, and 12 g of mixed spices. Postprandial blood was drawn up to 7 h at regular intervals and plasma phenolic acids were quantified via LC-MS/MS. Cinnamic acid (CNA, p < 0.0001) and phenylacetic acid (PAA, p < 0.0005) concentrations were significantly increased with mixed spices consumption, although none of the other measured phenolic acids differ significantly between treatments. CNA displayed a high dose-exposure association (R2 > 0.8, p < 0.0001). The adjusted mean AUC0-7 h for CNA during the 3 increasing doses were 8.4 ± 3.4, 376.1 ± 104.7 and 875.7 ± 291.9 nM·h respectively. Plasma CNA concentration may be used as a biomarker of spice intake.
ARTICLE | doi:10.20944/preprints202206.0188.v1
Subject: Chemistry, Other Keywords: Stigmatellin; Myxobacteria; Biosynthesis; Natural Products; Secondary Metabolites
Online: 13 June 2022 (12:58:42 CEST)
Myxobacteria generate natural products with unique chemical structures, which not only feature remarkable biological functions but also demonstrate unprecedented biosynthetic assembly strategies. The stigmatellins have been previously described as potent inhibitors of the mitochondrial and photosynthetic respiratory chain and originate from an unusual polyketide synthase assembly line. While previous biosynthetic investigations were focused on the formation of the 5,7-dimethoxy-8-hydroxychromone ring, side chain decoration of the hydrophobic alkenyl chain in position 2 was investigated less thoroughly. We report here the full structure elucidation as well as cytotoxic and antimicrobial activities of three new stigmatellins isolated from the myxobacterium Vitiosangium cumulatum MCy10943T with side chain decorations distinct from previously characterized members of this compound family. These findings provide further implications considering the side chain decoration of these aromatic myxobacterial polyketides and their underlying biosynthesis.
COMMUNICATION | doi:10.20944/preprints202203.0118.v1
Subject: Life Sciences, Biochemistry Keywords: myxobacteria; secondary metabolites; multifactorial OSMAC; screening method
Online: 8 March 2022 (08:51:31 CET)
The scarcely investigated myxobacterium Corallococcus coralloides holds a large genome containing many uncharacterized biosynthetic gene clusters (BGCs) that potentially encode the synthesis of entirely new natural products. Despite its promising genomic potential, suitable cultivation conditions have not yet been found to activate the synthesis of new secondary metabolites (SMs). Finding the right cultivation conditions to activate BGCs in the genome remained a major bottleneck and its full biosynthetic potential was so far not retrieved. Here, we therefore applied a bivariate OSMAC approach, using a combination of two elicitor changes at once for activation of BGCs and concomitant SM production by C. coralloides. The bivariate OSMAC screening was carried out in 24-well System Duetz-plates, applying univariate and bivariate OSMAC conditions. We combined biotic additives and organic solvents with minimal media and complex growth medium. The success of the method was evaluated by the number of new mass features detected in the respective extracts. We found synergistic effects in bivariate OSMAC designs. The number of new mass features detected in bivariate OSMAC exceeded the sum of new mass features found in the respective univariate OSMAC with only one elicitor. Overall, the bivariate OSMAC screening led to 26 new mass features, which were not detected in the univariate OSMAC design. Hence, the presence of multiple elicitors in the bivariate OSMAC designs successfully activated the biosynthetic potential in C. coralloides. We propose the bivariate OSMAC designs with a complex combination of elicitors as a straightforward strategy to robustly expand the SM space of microorganisms with large genomes.
ARTICLE | doi:10.20944/preprints201902.0124.v4
Subject: Life Sciences, Biophysics Keywords: enzymes Cyclooxygenase, ligand, metabolites, antiinflammatory, Molecular Docking
Online: 29 May 2019 (11:39:02 CEST)
Cyclooxygenases (COX), or prostaglandin endoperoxide synthases (PTGS), are key enzimes in the synthesis of prostaglandins, which are chemical species critical in mediating inflammatory processes. There are two highly homologous COX isoforms: COX-1 and COX-2. COX-1 is involved in the production of prostaglandins, chemical compuounds that take part in physiological processes such as: protection of the gastric epithelium, maintenance of renal flow, platelet aggregation, neutrophil migration and, also, are expressed in the vascular endothelium. Meanwhile, COX-2 is induced by proinflammatory stimuli. It is very frequent the use of nonsteroidal antiinflammatory drugs (NSAIDs) to counteract the symptoms of inflammatory processes. These drugs, in addition to its benefits, can cause side effects on people’s health, such as cardiovascular and respiratory problems, among others. In the past years, it has been recognized the potential of plants secondary metabolites as pharmacological agents, prompting the need for investigations that shed light into its mechanism of action. In this work we have applied computational techniques, based on quantum chemistry and mechanical statistics, to study the protein-ligand interaction involving COX’s and secondary metabolites from natural sources. Our aim is to determine the structure activity interplay in processes involving the participation of secondary plant metabolites such as luteolin, galangin, kaempferol, apigenin, morine and quercetin on the inactivation of COX’s. From molecular docking analysis, we have extracted the energetics of the COX-(1,2)/metabolite coupling. By defining energy based factors, we have determined a procedure that predicts the chemical species with highest stability and selectivity towards inactivation of COX-2 over COX-1. The results are discussed with regard to conformational features of the selected ligands and its intermolecular strong/weak interactions inside the active-sites of the COX’s hosts.
REVIEW | doi:10.20944/preprints201811.0166.v1
Subject: Life Sciences, Biotechnology Keywords: Biodegradation, thermophiles, petroleum hydrocarbons, aliphatics, aromatics, metabolites
Online: 7 November 2018 (14:34:42 CET)
Contamination of the environment by petroleum products is a growing concern worldwide, and strategies to remove these contaminants have been evaluated. One of these strategies is biodegradation, which consists of the use of microorganisms. Biodegradation is significantly improved by increasing the temperature of the milieu, thus, the use of thermophiles, microbes that thrive in high-temperature environments, will render this process more efficient. For instance, various thermophilic enzymes have been used in industrial biotechnology because of their unique catalytic properties. Biodegradation has been extensively studied in the context of mesophilic microbes, and the mechanisms of biodegradation of aliphatic and aromatic petroleum hydrocarbons have been elucidated. However, in comparison, little work has been carried out on the biodegradation of petroleum hydrocarbons by thermophiles. In this paper, a detailed review of the degradation of petroleum hydrocarbons (both aliphatic and aromatic) by thermophiles has been carried out. This work has identified the characteristics of thermophiles, and unravelled specific catabolic pathways of petroleum products that are only found in thermophiles. Gaps that limit our understanding of the activity of these microbes have also been highlighted, and finally, different strategies that can be used to improve the efficiency of degradation of petroleum hydrocarbons by thermophiles have been proposed.
REVIEW | doi:10.20944/preprints202207.0387.v1
Subject: Biology, Plant Sciences Keywords: Artocarpus; Artocarpus camansi; kamansi; phytochemistry; pharmacology; secondary metabolites
Online: 26 July 2022 (05:52:46 CEST)
Artocarpus camansi Blanco or breadnut (Family: Moraceae) is primarily found in tropical regions of the world. Different parts of the plant provide potential use in medicine, nutraceutical development, and livelihood. The present review attempts to document literature on the traditional use, nutritional value, phytochemistry, and pharmacological investigation carried out with breadnuts. The included literatures of the plant were collected from various sources and databases like Google scholar, PubMed, ScienceDirect, Crossref, and Scopus. Breadnuts are rich in secondary metabolites. Studies have reported the isolation of several triterpenoid compounds and the broad spectrum of its pharmacological activities such as antidiabetic, antimalarial, antioxidant, anti-tumor, antibacterial, and immunomodulatory properties. The approximate composition of the seed and the fruit also highlights the nutritional importance of this plant. A. camansi Blanco is an underutilized tree that holds significant potential if further research and sustainable conservation is applied. Efforts to mainstream its use as functional food and increase awareness among the locals should also be given attention.
ARTICLE | doi:10.20944/preprints202205.0186.v1
Subject: Life Sciences, Microbiology Keywords: collections of microorganisms; data bases; fungal diversity; metabolites
Online: 13 May 2022 (09:42:11 CEST)
This material presents the results of a comparative analysis of the fungal diversity in the world system of microbial culture collections on one side with a variety of known fungal producers on the other side. The main VKM databases used are Fungal DC and Metabolites of Fungi, the central point of analysis - the fungal ability to synthesize promising metabolites for applied use. It indicates that the option of obtaining new promising strains from the collection funds is still underestimated by the scientific community. In particular it is shown that not more than 3% of the total fungal species fund contained in culture collections are used practically. The database Fungal DC developed in VKM is available on-line in www.vkm.ru and www.mycobank.org. It is possible their use will considerably expand the range of studied strains and lead to the acquisition of new scientifically significant data.
Subject: Biology, 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.
ARTICLE | doi:10.20944/preprints202001.0217.v1
Subject: Biology, Plant Sciences Keywords: antioxidant; Nigella sativa; secondary metabolites; thymoquinone; DNA damage
Online: 19 January 2020 (14:33:58 CET)
Nigella sativa (NS) is an effective medicinal plant possessing noteworthy antioxidant property. In NS, there are more than hundred phyto-chemicals reported, out of which thymoquinone is the utmost active phyto-constituent having sturdy antioxidative property. Thymoquinone is a cyclicdione, when reacts with sodium azide, converts into α-azido ketones i.e its analogs which are handy with extensive range of reactions. Sodium azide induces stress in plants thereby, modulating the antioxidant system. The present investigation was planned to elucidate the effect of sodium azide at different concentrations (5µM, 10µM, 20µM, 50µM, 100µM and 200µM) on its secondary metabolites (mainly thymoquinone) in NS callus culture extract (NSE). The results showed sodium azide effect on thymoquinone content and a concentration dependent boost in antioxidant property. It was also observed that thymoquinone content and percent yield (analyzed by RP-HPLC; Reverse Phase- High Performance Liquid Chromatography) were minimum (0.033±0.006% and 0.420±0.045%, respectively) at 200 µM sodium azide used. Whereas, antioxidant activity (analyzed by DPPH; 2, 2-diphenyl-1-picrylhydrazyl) was found to be maximum (3.873±0.402%) at same dose. Further, analysis was done for inhibition of oxidative DNA damage at different concentrations of sodium azide on NSE, maximum inhibition of DNA damage (0.243±0.017%) was found at 200 µM concentration of sodium azide. When correlated, strong positive correlation was observed between percent yield and percent thymoquinone, antioxidant property and inhibition of DNA damage. Whereas, strong negative correlation was observed between percent yield and antioxidant property, percent thymoquinone and antioxidant property, percent thymoquinone and inhibition of DNA damage. The findings evidently point out that the content of thymoquinone, antioxidant property and inhibition of DNA damage was affected by sodium azide.
REVIEW | doi:10.20944/preprints202211.0060.v1
Subject: Chemistry, Organic Chemistry Keywords: secondary metabolites; pharmacological activities; qualitative and quantitative analysis; techniques
Online: 2 November 2022 (13:47:27 CET)
Plant secondary metabolites are organic compounds (alkaloids, flavonoids, phenolics, tannins, anthraquinones, saponins, steroids, lignins, terpenes) produced by plant for self-defense during growth and development in order to protect them from harmful agents. As population is increasing and quality of life is reducing couple with outbreak of some diseases that are posing threat on the economy, a lot of medicinal plants have attracted interest of researchers because of the usefulness of these metabolites in pharmaceuticals, food and cosmetic industries. In this review, the pharmacological activities of some medicinal plants that are rich in secondary metabolites were studied, means of identifying and quantifying using spectrophotometry and chromatography techniques were also discussed. However, this will assist to reduce the uses and dependent on the synthetic drug and the onset of the age related diseases.
ARTICLE | doi:10.20944/preprints202008.0005.v1
Subject: Biology, Forestry Keywords: birch; chlorophyll; leaves’ damage; plants’ pathogens; roots; secondary metabolites
Online: 2 August 2020 (08:47:32 CEST)
The purpose of this study was to better understand the interactive impact of two soil-borne pathogens, Phytophthora cactorum (as the primary pathogen) and Armillaria gallica (as secondary), on two-year-old seedlings of silver birch (Betula pendula) subjected to stress caused by mechanical defoliation simulating primary insect feeding. One year after treatments, the chlorophyll fluorescence measurement and gas chromatography coupled with mass spectrometry (GC-MS) were used to analyze the photosynthetic activity in leaves, the volatile organic compounds (VOCs) emitted by birch leaves and chemical compounds from roots. Only the infection of roots by P. cactorum increased photosynthetic rates in the leaves, which may suggest its cryptic development in contrast to fungi. The birch leaves in seedlings exposed to 50% defoliation, inoculation with P. cactorum and A. gallica emitted more aromatic carbonyls and alcohols, as well as half as much aliphatic esters, compared to untreated controls. In infected birch roots, the production of phenols, triterpenes and fatty alcohols increased, but fatty acids decreased. This was the first experimental confirmation of the pathogenicity of P. cactorum on silver birch seedlings in Poland. The most severe damage to roots took place only in the case of two-way or three-way interactions. Higher levels of aromatic carbonyls and alcohols in leaves, as well as phenolic compounds in roots of stressed birches (compared to control) suggest an activation of plant systemic acquired resistance (SAR).
Subject: Life Sciences, Microbiology Keywords: cananbis sativa; marijuana; hemp; microbiome; endophytes; secondary metabolites; Cannabinoids
Online: 15 January 2020 (07:04:25 CET)
Plants, including Cannabis (Cannabis sativa subsp. sativa) host distinct beneficial microbial communities on and inside their tissues, designated the plant microbiota from the moment that they are planted into the soil as seed. They contribute to plant growth promotion, facilitating mineral nutrient uptake, inducing defense resistance against pathogens, higher yield and modulating plant secondary metabolites. Understanding the microbial partnerships with Cannabis has the potential to affect agricultural practices by improving plant fitness and the production yield of cannabinoids. Much less is known about this beneficial Cannabis-microbe partnership, and the complex relationship between the endogenous microbes associated with various tissues of the plant, particularly, the role that cannabis may play in supporting or enhancing them. This review will focus on Cannabis microbiota studies and the effect of endophytes on the elicitation of secondary metabolites production in Cannabis plants. The aim of this review is to shed light on the importance of Cannabis microbiome and how cannabinoid compounds concentration can be stimulated through symbiotic and or mutualistic relationships with endophytes.
Subject: Chemistry, Organic Chemistry Keywords: secondary metabolites; microbial diversity; metabolomics; molecular network; marine bacteria
Online: 19 October 2019 (02:01:18 CEST)
Rocas Atoll is a unique environment in the Equatorial Atlantic Ocean, hosting a large number of endemic species and studies on the chemical diversity emerging from this biota are rather scarce. Therefore, the present work aims to assess the metabolomic diversity and pharmacological potential of the microbiota from Rocas Atoll. A total of 76 bacteria were isolated and cultured in liquid culture media to obtain crude extracts. About one third (34%) of these extracts were considered cytotoxic against human colon adenocarcinoma HCT-116 cell line. 16S rRNA gene sequencing analysis revealed that the bacteria producing cytotoxic extracts are mainly from the Actinobacteria phylum, including Streptomyces, Salinispora, Nocardiopsis and Brevibacterium genera, and in a smaller proportion from Firmicutes phylum (Bacillus). The search in the GNPS spectral library unveiled a high chemodiversity being produced by these bacteria, including rifamycins, antimycins, desferrioxamines, ferrioxamines, surfactins, surugamides, staurosporine and saliniketals, along with several unidentified compounds. Using an original approach, molecular network successfully highlighted groups of compounds responsible for the cytotoxicity of crude extracts. DEREPLICATOR+, a recently developed in silico tool (GNPS), allowed the identification of derivatives of the macrolide novonestimycin, as the cytotoxic compounds into the extracts produced by Streptomyces BRB-298 and BRB-302. Overall, these results highlighted the pharmacological potential of bacteria from this singular Atoll.
REVIEW | doi:10.20944/preprints201905.0063.v1
Subject: Biology, Ecology Keywords: biotechnologies; marine bacteria; secondary metabolites; nonribosomal biosynthesis; antibacterial strategies
Online: 6 May 2019 (12:15:50 CEST)
The highly dangerous trend of escalating bacterial resistance to modern antibiotics has evolved in recent decades, with increasingly more drug-resistant strains of pathogens emerging and spreading each year. This poses a threat to not only public health, but also to entire mankind. Marine bioresources, considered as a promising alternative to traditional antibiotics and a valuable source of biologically active compounds with high pharmacological potential, now attract increasing attention of researchers. Modern biotechnology combines the genetic engineering methods and the unusual biosynthetic pathways utilized by marine microorganisms to produce natural antibiotics. The goal of this review is to summarize the latest trends in searching for new natural antimicrobial agents based on secondary metabolites of marine bacteria. The targeted control of biosynthesis mechanisms using the metabolic engineering methods in order to create hybrid peptide synthetases or to obtain hybrid peptides by disrupting the target gene of nonribosomal synthesis becomes a noteworthy trend in modern biotechnology. This pathway is not only one of the most promising approaches to the development of new antibiotics, but also a potential target for controlling the exocrine activity of pathogenic bacteria and, consequently, their viability.
ARTICLE | doi:10.20944/preprints201904.0192.v1
Subject: Life Sciences, Microbiology Keywords: cyanobacteria; natural products; metabolites; biological activities; producers; chemical classes
Online: 17 April 2019 (06:05:45 CEST)
Cyanobacteria are photosynthetic microorganisms that colonize diverse environments worldwide, ranging from ocean to freshwaters, soils, and extreme environments. Their adaptation capacities and the diversity of natural products (molecules, metabolites, or compounds) that they synthesize support the cyanobacterial success for the colonization of their respective ecological niches. Although cyanobacteria are well-known for their toxin production and their relative deleterious consequences, they also produce a large variety of molecules that exhibit beneficial properties with high potential for various fields of application (e.g., synthetic analog of the dolastatin 10 used against Hodgkin lymphoma). The present review specially focuses on the beneficial activities of cyanobacterial molecules described so far. Based on an analysis of 670 papers, it appears that more than 90 genera of cyanobacteria have been found to produce compounds with potential beneficial activities, most of them belonging to the orders Oscillatoriales, Nostocales Chroococcales, and Synechococcales. The rest of the cyanobacterial orders (i.e., Pleurocapsales, Chroococcidiopsales, and Gloeobacterales) remain poorly explored in terms of their molecular diversity and relative bioactivity. The diverse cyanobacterial molecules presenting beneficial bioactivities belong to 10 different chemical classes (alkaloids, depsipeptides, lipopeptides, macrolides/lactones, peptides, terpenes, polysaccharides, lipids, polyketides, and others) that exhibit 14 major kinds of bioactivity. However, no direct relation between the chemical class and the bioactivity of these molecules has been demonstrated. We further selected and specifically described 50 molecule families according to their specific bioactivities and their potential uses in pharmacology, cosmetology, agriculture, or other specific fields of interest. This up-to-date review takes advantage of the recent progresses in genome sequencing and biosynthetic pathway elucidation, and presents new perspectives for the rational discovery of new cyanobacterial metabolites with beneficial bioactivity.
ARTICLE | doi:10.20944/preprints201809.0098.v1
Subject: Life Sciences, Other Keywords: Freshwater fish; Soup; Metabolites; 1H-NMR; In vitro digestion;
Online: 5 September 2018 (13:00:17 CEST)
Soups show diverse health functions, which should be related with their nutrient profiles. NMR spectroscopy is a robust, sensitive and rapid method to unveil or identify the chemical composition of food or food-derived metabolites. In the current study, 1H-NMR spectroscopy approach was applied to identify the metabolic profiling of two kinds of home-cooked freshwater fish soups (crucian carp and snakehead fish) before and after in vitro gastrointestinal digestion. The nutritional profiles of these two kinds of soups were identified at first. With the help of OPLS-DA method (Orthogonal Partial Least Squares Discriminant Analysis), these two different kinds freshwater fish under different states were completely discriminated. The metabolites changes in digested fish soups could reveal the information of chemical compounds which play important roles in the body. Furthermore, the metabolic patterns of different kinds of fish soups could reflect the various nutrition profiling characteristics for dietary therapy.
REVIEW | doi:10.20944/preprints201807.0143.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Aromatic hydroxy metabolites; arenolic drug metabolites; metabolic O-dealkylation; metabolic aromatic ring hydroxylation; primary and auxiliary pharmacophores; auxophores; metabolic modification of drug activity
Online: 9 July 2018 (13:28:16 CEST)
Drug functionalization through formation of hydrophilic groups is the norm in phase I metabolism of drugs for modification of drug action. The reactions involved are mainly oxidative catalyzed mostly by CYP isoenzymes. The benzene ring, as phenyl or fused with other rings, is the most common hydrophobic pharmacophoric moiety in drug molecules. On the other hand the alkoxy group (mainly methoxy) bonded to the benzene ring assumes an important and sometimes essential pharmacophoric status in some drug classes. Upon metabolic oxidation, both moieties, i.e. the benzene ring and the alkoxy group, produce hydroxy groups; the products are arenolic in nature. Through a pharmacokinetic effect, the hydroxy group enhances the water solubility and elimination of the metabolite with the consequent termination of drug action. However, through hydrogen bonding, the hydroxy group may modify the pharmacodynamics of the interaction of the metabolite with the site of parent drug action (i.e. the receptor). Accordingly, the expected pharmacologic outcome will be enhancement, retaining, attenuation, or loss of activity of the metabolite relative to the parent drug. All the above issues have been presented and discussed in this review using selected members of different classes of drugs with inferences regarding mechanisms, drug design and drug development.
ARTICLE | doi:10.20944/preprints202204.0005.v1
Subject: Medicine & Pharmacology, Other Keywords: genome mining; marine environments; molecular networking; bacterial extremophiles; secondary metabolites
Online: 1 April 2022 (10:21:11 CEST)
Understanding extremophiles and their usefulness in biotechnology involves studying their habitat, physiology and biochemical adaptations , as well as their ability to produce biocatalysts, in environments that are still poorly explored. In northwestern Peru, which saline lagoons of marine origin Pacific Ocean, the other site from the coast of Brazil of the Atlantic Ocean. Both environments are considered extreme. The objective of the present work was to compare two different strains isolated from these extreme environments at the metabolic level using molecular network methodology through the Global Natural Products Molecular Social Network (GNPS). In our study, the MS/MS spectra from the network were compared with GNPS spectral libraries, where the metabolites were annotated. Differences were observed in the molecular network presented in the two strains of Streptomyces spp. coming from these two different environments. Within the annotated compounds from marine bacteria, the metabolites characterized for Streptomyces sp. B-81 from Peruvian marshes were lobophorins A (1) and H (2), as well as divergolides A (3), B (4) and C (5). Streptomyces sp. 796.1 produced different compounds, such as glucopiericidin A (6) and dehydro-piericidin A1a (7). The search for new metabolites in underexplored environments may therefore reveal new metabolites with potential application in different areas of biotechnology.
ARTICLE | doi:10.20944/preprints202110.0043.v1
Subject: Biology, Agricultural Sciences & Agronomy Keywords: Grass; Greenhouse Gases; Ruminal Degradation; Secondary Metabolites; Tropical Livestock Systems
Online: 4 October 2021 (10:40:05 CEST)
Enteric methane (CH4) emitted by ruminant species is known as one of the main greenhouse gases produced by the agricultural sector. The objective of this study was to evaluate the chemical composition, in vitro gas production, dry matter degradation (DMD), digestibility, CO2 production and CH4 mitigation potential of five tropical tree species with novel forage potential including: Spondias mombin, Acacia pennatula, Parmentiera aculeata, Brosimum alicastrum and Bursera simaruba mixed at two levels of inclusion (15 and 30%) with a tropical grass (Pennisetum purpureum). Crude protein content was similar across treatments (135 g kg-1 DM), while P. purpureum was characterized by a high content of acid detergent fiber (335.9 g kg-1 DM) and B. simaruba by a high concentration of condensed tannins (20 g kg-1 DM). Likewise, A. pennatula and P. aculeata were characterized by a high content of cyanogenic glycosides and alkaloids respectively. Treatments SM30-PP70 (30% S. mombin + 70% P. purpureum) and BA30-PP70 (30% B. alicastrum + 70% P. purpureum) resulted in superior digestibility than P. purpureum, while in the AP30-PP70 (30% A. pennatula + 70% P. purpureum) was lower than the control treatment (P≤0.05). At 24 and 48 h, treatments that contained P. aculeata and B. alicastrum produced higher CH4 ml g-1 DOM than P. purpureum (P≤0.05). The inclusion of B. simaruba at 30% reduced CH4 at 25% compared to P. purpureum. Tropical tree species can improve the nutritional quality of ruminant rations and reduce CH4 emissions to consequently contribute to the development of sustainable ruminant production systems that generate diverse ecosystem services.
REVIEW | doi:10.20944/preprints202010.0551.v2
Subject: Medicine & Pharmacology, General Medical Research Keywords: cannabinoids; Δ9-tetrahydrocannabinol; cannabidiol; non-cannabinoids; flavonoids; terpenes; secondary metabolites
Online: 26 November 2020 (11:13:18 CET)
The Cannabis plant (Cannabis sativa L.) produces an estimated 545 chemical compounds of different biogenetic classes. In addition to economic value, many of these phytochemicals have medicinal and physiological activity. The plant is most popularly known for its two most prominent and most studied secondary metabolites— Δ9-Tetrahydrocannabinol (Δ9-THC) and Cannabidiol (CBD). Both Δ9-THC and CBD have a wide therapeutic window across many ailments and form part of a class of secondary metabolites called cannabinoids—of which approximately over 104 exist. This review will focus on non-cannabinoid metabolites of Cannabis sativa that also have therapeutic potential, some of which share medicinal properties similar to those of cannabinoids. The most notable of these non-cannabinoid phytochemicals are flavonoids and terpenes. We will also discuss future directions in cannabis research and development of cannabis-based pharmaceuticals. Caflanone, a flavonoid molecule with selective activity against the human viruses including the coronavirus SARS-COV2, and certain cancers, is one of the most promising non-cannabinoid molecules that is being advanced into clinical trials. As validated by thousands of years of the use of cannabis for medicinal purposes, vast anecdotal evidence abounds on the medicinal benefits of the plant. These benefits are attributed to the many phytochemicals in this plant, including non-cannabinoids. The most promising non-cannabinoids with potential to alleviate global disease burdens are discussed.
Subject: Physical Sciences, Other Keywords: rumen-protected l-tryptophan; growth performance; metabolites; glucose; gene expression
Online: 29 September 2019 (09:02:27 CEST)
We assessed the growth performance, physiological traits, and gene expressions in steers fed with dietary rumen-protected L-tryptophan (RPT) under cold environment. Eight Korean native steers were assigned to two dietary groups, no RPT (Control) and RPT (0.1% RPT supplementation on a dry matter basis), 6 wks. Maximum and minimum temperatures throughout the experiment were 6.7°C and -7.0°C, respectively. Supplementation of 0.1% RPT to a total mixed ration did not increase body weight but had positive effects of elevating average daily gain (ADG) and reducing the feed conversion ratio (FCR) at day 27 and 48. Metabolic parameter showed higher glucose level (at day 27) in the 0.1% RPT group compared to the control group. Real-time PCR analysis showed no significant differences in the expression of muscle (MYF6, MyoD, and Desmin) metabolism genes between the two groups, whereas the expression of fat (PPARγ, C/EBPα, and FABP4) metabolism genes was lower in the 0.1% RPT group than in the control group. Thus, we demonstrate that long-term (6 wks) dietary supplementation of 0.1% RPT was beneficial owing to enhanced growth performance by increasing ADG and glucose level, decreasing FCR, and maintaining homeostasis in immune responses in beef steers during cold environment.
ARTICLE | doi:10.20944/preprints201810.0113.v1
Subject: Chemistry, Food Chemistry Keywords: Sea Squirts; Metabolites; GC-MS; Anti-bacterial; Zika vector; larvicidal
Online: 6 October 2018 (11:18:31 CEST)
In this present study, we conducted untargeted metabolic profiling using Gas Chromatography-Mass Spectrometry (GC-MS) analysis of ascidian Didemnum bistratum to assess the chemical constituents by searching in NIST library with promising biological properties against anti-bacterial and Zika virus vector mosquitocidal Properties. Metabolites, steroids and fatty acids are abundant in crude compounds of ascidian D. bistratum and showed potential zone growth inhibition against bacterial strains Kluyvera ascorbate (10 mm). The active crude compounds of D. bistratum exhibited prominent larvicidal activity against the Zika vector mosquitoes of Aedes aegypti and Cluex quinquefasciatus (LC50 values of 0.4436 to 2.23 mg/mL). The findings of this study provide a first evidence of the biological properties exhibited by D. bistratum extracts, thus increasing the knowledge about the Zika virus vector mosquitocidal properties of ascidian. Overall, ascidian D. bistratum are promising and biocontrol or eco-friendly tool against A. aegypti and C. quinquefasciatus with prospective toxicity against non-target organisms.
ARTICLE | doi:10.20944/preprints201807.0549.v1
Subject: Chemistry, Organic Chemistry Keywords: Smenospongia aurea, -pyrone, polypropionate, marine sponges, secondary metabolites, signaling molecules.
Online: 27 July 2018 (17:00:51 CEST)
The organic extract of the Caribbean sponge Smenospongia aurea has been shown to contain an array of novel chlorinated secondary metabolites derived from a mixed PKS-NRPS biogenetic route, such as the smenamides. Here we report the presence of a biogenetically different compound, smenopyrone (1), a polypropionate containing two -pyrone rings. The structure of smenopyrone, including its relative and absolute stereochemistry, was determined by spectroscopic analysis (NMR, MS, ECD) supported by comparison with model compounds from the literature. Pyrone polypropionates are unprecedented in marine sponges, but are commonly found in marine mollusks, where their biosynthesis by symbiotic bacteria has been hypothesized and at least in one case demonstrated. As pyrones have recently been recognized as bacterial signaling molecules, we speculate that smenopyrone could mediate inter-kingdom chemical communication between S. aurea and its symbiotic bacteria.
ARTICLE | doi:10.20944/preprints201802.0151.v1
Subject: Biology, Plant Sciences Keywords: color tests; thin layer chromatography; chemotaxonomy; secondary metabolites; solvent system
Online: 24 February 2018 (08:28:11 CET)
Presence and identity of secondary metabolites are two of the main components of lichen taxonomy. Aromatic compounds formed via the acetyl-polymalonate pathway are the most studied lichen substances. In addition, compounds derived from the mevalonic acid pathway (e.g., terpenes and steroids) are sometimes detected in the medulla. However, their identity and value as diagnostic characters in the genus Usnea are yet poorly understood despite the fact that they were mentioned in several taxonomical papers. We conclude that i) aside from the previously recognized polyphenolic compounds, carbohydrates and steroids are also detected in the medulla of some Usnea species; ii) the use of sulfuric anisaldehyde reagent greatly improves the detection of terpenes, carbohydrates and steroids compared with the sulfuric acid reagent routinely used in thin layer chromatography; iii) among carbohydrates, we detected arabitol and sucrose in the medulla; iv) steroids and terpenes remain unidentified and deserve further investigations.
ARTICLE | doi:10.20944/preprints202211.0116.v1
Subject: Medicine & Pharmacology, Pediatrics Keywords: 2-year-old children; respiratory diseases; influenza; OH-PAHs; metabolites; urine
Online: 7 November 2022 (10:12:30 CET)
Aim: Exposure to polycyclic aromatic hydrocarbons (PAHs) has been in the past associated with adverse effects on human health among which belong also respiratory diseases. Our study is focused on the evaluation of PAH exposure by measuring the concentrations of their monohydroxylated metabolites (OH-PAHs) in urine and comparing their concentrations with the incidence of respiratory diseases in 2-year-old children from two locations of the Czech Republic – a control locality Ceske Budejovice and a previously highly contaminated mining district Most. Methods: The total number of 248 participants were sampled for urine samples that were analysed for the presence of 11 OH-PAHs using liquid-liquid extraction with ethyl acetate and clean-up employing dispersive solid phase extraction with a sorbent Z-Sep. Separation, identification and quantification of the target compounds was achieved by ultra-high performance liquid chromatography coupled to tandem mass spectrometry. The incidence of respiratory diseases was evaluated according to the questionnaires provided by the paediatricians. Results and discussion: The concentrations of measured OH-PAHs were higher in the urine samples collected from 2-year-old children living in Most compared to 2-year-old children from Ceske Budejovice. The same trend was observed also when the urine samples were analysed when these children were studied as newborns in our previous study. From all of the monitored respiratory diseases, only influenza due to unidentified influenza virus showed a difference between tested locations where the 2-year-old children living in Most were more frequently diagnosed with this disease. Conclusion: Even though the air pollution and lifestyle in both cities is very similar, we have observed higher incidence of respiratory diseases as well as higher concentration of OH-PAHs in urine of the 2-year-old children from Most. Therefore, we hypothesize that the population living in this previously highly contaminated location (in 1970s and 1980s) can carry some long-term health burden.
ARTICLE | doi:10.20944/preprints202111.0467.v1
Subject: Chemistry, Organic Chemistry Keywords: myxobacteria; secondary metabolites; biarylitide; natural product discovery; RiPPs; genome mining; myxarylin
Online: 25 November 2021 (10:42:39 CET)
Ribosomally synthesized and post-translationally modified peptides (RiPPs) are a structurally diverse group of natural products. They feature a wide range of intriguing posttranslational modifications as exemplified by the biarylitides. These are a family of cyclic tripeptides found in Planomonospora, carrying a biaryl-linkage between two aromatic amino acids. Recent genomic analyses revealed the minimal biosynthetic prerequisite of biarylitide biosynthesis consisting of only one ribosomally synthesized pentapeptide precursor as substrate and a modifying cytochrome P450 dependent enzyme. In silico analyses revealed that the minimal biarylitide RiPP clusters are widespread among natural product producers across phylogenetic borders including myxobacteria. We report here the genome-guided discovery of the first myxobacterial biarylitide MeYLH termed Myxarylin from Pyxidicoccus fallax An d48. Myxarylin was found to be an N-methylated tripeptide surprisingly exhibiting a C–N biaryl crosslink. In contrast to Myxarylin, previously isolated biarylitides are N-acetylated tripeptides featuring a C–C biaryl crosslink. Furthermore, the formation of Myxarylin was confirmed by heterologous expression of the identified biosynthetic genes in Myxococcus xanthus DK1622. These findings expand the structural and biosynthetic scope of biarylitide type RiPPs and emphasize the distinct biochemistry found in the myxobacterial realm.
ARTICLE | doi:10.20944/preprints202108.0235.v1
Subject: Life Sciences, Endocrinology & Metabolomics Keywords: Pancreatic Ductal Adenocarcinoma; metabolites; cholestatic (obstructive) jaundice; lipoprotein; inflammation; tumour stages
Online: 10 August 2021 (14:08:27 CEST)
Pancreatic ductal adenocarcinoma (PDAC) is a lethal cancer with a characteristic dysregulated metabolism. Abnormal clinicopathological features linked to defective metabolic and inflammatory response pathways can induce PDAC development and progression. In this study, we investigated the metabolites and lipoproteins profiles of PDAC patients of African ancestry. Nuclear Magnetic Resonance (NMR) spectroscopy was conducted on serum obtained from consenting individuals (34 PDAC, 6 Chronic Pancreatitis, and 6 healthy participants). Seventy-five signals were quantified from each NMR spectrum. The Liposcale test was used for lipoprotein characterization. Spearman’s correlation and Kapan Meier tests were conducted for correlation and survival analyses respectively. In our patient cohort, the results demonstrated that levels of metabolites involved in the glycolytic pathway increased with the tumour stage. Raised ethanol and 3-hydroxybutyrate were independently correlated with a shorter patient survival time, irrespective of tumour stage. Furthermore, increased levels of bilirubin resulted in an abnormal lipoprotein profile in PDAC patients. Additionally, we observed that the levels of a panel of metabolites (such as glucose, lactate) and lipoproteins correlated with those of inflammatory markers. Taken together, the metabolic phenotype can help distinguish PDAC severity and be used in predicting patient survival and in informing treatment intervention.
REVIEW | doi:10.20944/preprints202011.0276.v2
Subject: Medicine & Pharmacology, Gastroenterology Keywords: Vitamin D; VDR; inflammation; microbiome; metabolites; nuclear receptor; probiotics; tight junctions
Online: 24 December 2020 (09:55:13 CET)
Inflammatory bowel disease (IBD) is a chronic inflammation of the gastrointestinal0 tract (GIT), including Crohn’s disease (CD) and ulcerative colitis (UC), which differ in the location and lesion extensions. Both diseases are associated with microbiota dysbiosis, with a reduced population of butyrate-producing species, abnormal inflammatory response, and micronutrient deficiency (e. g. vitamin D hypovitaminosis). Vitamin D (VitD) is involved in immune cell differentiation, gut microbiota modulation, gene transcription, and barrier integrity. Vitamin D receptor (VDR) regulates the biological actions of the active VitD (1α, 25-dihydroxyvitamin D3), and is involved in the genetic, environmental, immune, and microbial aspects of IBD. VitD deficiency is correlated with disease activity and its administration targeting a concentration of 30 ng/mL may have the potential to reduce disease activity. Moreover, VDR regulates functions of T cells and Paneth cells and modulates release of antimicrobial peptides in gut microbiota-host interactions. Meanwhile, beneficial microbial metabolites, e.g. butyrate, upregulate the VDR signaling. In this review, we summarize the clinical progress and mechanism studies on VitD /VDR related to gut microbiota modulation in IBD. We also discuss epigenetics in IBD and the probiotic regulation of VDR. Furthermore, we discuss the existing challenges and future directions. There is a lack of well-designed clinical trials exploring the appropriate dose and the influence of gender, age, ethnicity, genetics, microbiome, and metabolic disorders in IBD subtypes. To move forward, we need well-designed therapeutic studies to examine whether enhanced vitamin D will restore functions of VDR and microbiome in inhibiting chronic inflammation.
ARTICLE | doi:10.20944/preprints202006.0358.v1
Subject: Chemistry, Medicinal Chemistry Keywords: Enzyme inhibition; Secondary Metabolites; In-silico Analysis; Molecular docking; Drug candidates
Online: 30 June 2020 (08:11:28 CEST)
Metabolic enzymes are often targeted for drug development programs of metabolic diseases such as diabetes and its complications. Many secondary metabolites isolated from natural products have shown therapeutic action against these enzymes. However, some commercially available synthetic drugs have shown unfriendly impacts with various side effects. Thus, this research has focused on a comprehensive study of secondary metabolites showing better inhibitory activities towards metabolic enzymes such as α-amylase, α-glucosidase, aldose reductase, and lipase. Further receptor-based virtual screening was performed against the various secondary metabolites database designed in-silico. Using Gold combined with subsequent post-docking analyses, the score was obtained as methyl xestospongic ester (Gold score 65.83), 2,″4″-O-diacetylquercitrin (Gold score 65.15), kaempferol-3-O-neohesperidoside (Gold score 53.37) and isosalvianolic acid C methyl ester (Gold score 53.44) for lipase, aldol reductase, α-amylase, and α-glucosidase, respectively. Besides, vitexin and isovitexin for α-amylase; N-trans-Caffeoyl-tyramin for α-glucosidase; purpurolide F and schaftoside for lipase; acteoside and orientin for aldose reductase could be potential drugs for respective enzymes based on in-silico analyses, supported by experimental IC50 values reported. They could bind to the competitive sites of the various targets of metabolic enzymes, and finally, toxicity analysis using ProTox-II was also performed.
ARTICLE | doi:10.20944/preprints201809.0319.v1
Subject: Life Sciences, Molecular Biology Keywords: Oxidative stress; blackcurrant; biofunctional cookie; simulated digestion; bioactive metabolites; inflammatory cytokines
Online: 17 September 2018 (15:05:44 CEST)
The improved understanding of the underlying mechanisms of oxidative damage and/or chronic diseases is of high priority in dietary research. Although the chemical extraction of biofunctional molecules from different fruits and cereals have been studied extensively, the impact of food processing and digestion on bioactivity has not been studied systematically. The aim of this study was to investigate the biofunctional potential of blackcurrant powder incorporated into wholemeal wheat and barley cookies in after simulated in vitro digestion. The incorporation of blackcurrant significantly (p<0.05) increased the total phenolic content (about 60 %), significantly improved oxygen radical absorbance capacity (about 25 %) of the cookie digesta. Additionally cellular antioxidant and anti-proliferative activity (lowest EC₅₀ value 1.02 mg/mL) on human liver cancer cell model, HepG2 was significantly enhanced. Bioactive metabolites of blackcurrant incorporated cookies were significantly supressed the inflammatory cytokine genes IL-1β (about 3-fold), IL-6 (about 0.5-fold) and NF-kB (about 2-fold) regulation and upregulated satiety gene NUCB-2/Nesfatin-1 (about 5-fold) compare with wholemeal wheat and barley control cookies. The exerted synergistic effects of this study suggest that there may be a new and effective option to prevent and control chronic diseases in human.
COMMUNICATION | doi:10.20944/preprints202209.0147.v1
Subject: Life Sciences, Microbiology Keywords: Myxochelin; Myxobacteria; Biosynthesis; Natural Products; Secondary Metabolites; Succinylation; Siderophore; Succinyl-coenzyme A
Online: 12 September 2022 (12:22:43 CEST)
Myxobacteria feature unique biological characteristics including their capability to glide on surface, undergo different multicellular developmental stages and produce structurally unique natural products such as the catecholate-type siderophores myxochelin A and B. Herein, we report the isolation, structure elucidation and biosynthesis of the new congener myxochelin B-succinate from the terrestrial myxobacterial strain MSr12020, featuring a succinyl decoration at its primary amine group. Myxochelin-B-succinate exhibited antifungal growth inhibition and moderate cytotoxic activity against selected human cancer cell lines. This unique chemical modification of myxochelin B might provide interesting insights for future microbiological studies to understand the biological function and biosynthesis of secondary metabolite succinylation.
ARTICLE | doi:10.20944/preprints202204.0119.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: Micromeria fruticosa; GC-MS; metabolites; anticancer activity; MTT; antioxidant activity; antimicrobial activity
Online: 13 April 2022 (08:29:56 CEST)
This study assesses the secondary metabolites, minerals, antimicrobial, antioxidant, and anticancer properties of Micromeria fruticosa plant different botanical parts (leaf, stem, root, flower) extracted with various solvents. The plant samples were sequentially obtained using different solvents (n-hexane, ethanol and water) through steeping. Then, each of the extracts was further analyzed by using gas chromatography–mass spectrometry (GC-MS). Moreover, the extracts were bio-assayed to test their antioxidant, antibacterial, and anti-cancer activities. Quali-quantitative analysis of M. fruticosa crude extracts revealed the occurrence of 27 secondary metabolites were identified including mainly monoterpenes, sesquterpenes, and fatty acids, with varying quantities. Some of the major bioactive compounds included, Menthone (5.42-30.05%), Oleamide (3.40-32.20%), Pulegone (10.66-64.1%), and Menthol (3.61-100.0%), which were detected mostly in all plant parts with significant quantities. Several antioxidant minerals, mainly, Fe, Zn, and Mn, were detected with the highest amounts in the Micromeria water extracts. Results from antimicrobial assays showed that the water extract of leaves exhibited the highest DPPH scavenging activity (89.73%) followed by the water extract of flowers (80.07%) at a concentration of 100 μg/mL. The water extract of stems showed greater antimicrobial activity against all the tested gram negative and positive bacteria (Methicillin-resistant Staphylococcus aureus, Staphylococcus aureus, Escherichia coli, and Shigella sonnie). The leaves ethanolic and stem aqueous extracts had a strong antimicrobial activity against E. coli. and C. albicans. Flower aqueous extract demonstrated the highest cytostatic effect on the colon cell line by reducing viability up to 30.4%, followed by the leaf ethanol extract with 38.6% cell viability reduction at 1000 µg/mL. In conclusion, extraction solvents influenced the recovery of phytocompounds and the highest pharmacological activities of the different extracts could be correlated to the presence of additional bioactive compounds. Our results suggest that M. fruticosa plant is a promising source of natural products with antioxidant, anti-microbial and anti-cancer properties for potential nutraceutical, therapeutic, and functional food applications. , , , , , ,
ARTICLE | doi:10.20944/preprints202103.0203.v1
Subject: Biology, Anatomy & Morphology Keywords: Antimicrobial activity; Characterization; GC-MS analysis; FTIR analysis; Red lily; Secondary metabolites
Online: 5 March 2021 (21:42:00 CET)
The members of the Liliaceae family have been regarded as an excellent source of biologically active compounds. However, the work on antimicrobial potential and characterization of the bioactive fractions of Lilium philadelphicum flower is limited and needs to be explored. The present study reports the antimicrobial potential, anti-inflammatory and anticancer potential of the bioactive fraction extracted from the flower of L. philadelphicum (Red Lily) and characterization of these bioactive compounds. The antimicrobial activity was tested against nine different Gram-positive and Gram-negative bacterial strains. The minimum inhibitory concentration (MIC) values of methanolic extract of L. philadelphicum flower against Acinetobacter bouvetii, Achromobacter xylosoxidans, Bacillus subtilis MTCC 121, Candida albicans MTCC 183, Klebsiella pneumoniae MTCC 3384, and Salmonella typhi MTCC 537 were 25, 50, 12.5, 50, 100 and 50 μg mL-1, respectively. The phytochemical analysis of the extract reveals the presence of phenols, flavonoids, tannins, terpenoids, glycosides, coumarins, and quinones. The cytotoxicity of the partially purified compound against the HepG2 cell line in MTT assay demonstrates up to 90% cell viability with a bioactive compound concentration of 50 μg/ml. However, with the increase in bioactive compound concentration up to 1000 μg/ml results into nearly 80% cell viability, just a minor decline in cell viability suggests the importance of bioactive compounds for suitable therapeutic applications. Spectroscopic studies of the bioactive compound by UV-Visible spectroscopy, FT-Infra Red spectroscopy, Gas Chromatography-Mass Spectrometry (GCMS) as well as its phytochemical analysis suggests the presence of terpenoids moiety, responsible for the antimicrobial property of L. philadelphicum flower.
REVIEW | doi:10.20944/preprints202012.0378.v1
Subject: Life Sciences, Biochemistry Keywords: gastrointestinal tract; dietary antigens; metabolites; microbiota; macronutrients; gastrointestinal immunity; mucosal immune regulation
Online: 15 December 2020 (12:20:48 CET)
The gastrointestinal tract contains multiple types of immune cells that maintain the balance between tolerance and activation at the first line of host defense facing non-self antigens, including dietary antigens, commensal bacteria, and sometimes unexpected pathogens. Maintaining homeostasis at the gastrointestinal tract requires stringent regulation of the immune responses against various environmental conditions. Diet can be converted into gut metabolites which have unique functional activities through host as well as microbial enzymatic activities. Accumulating evidences demonstrate that gastrointestinal metabolites have significant impacts on the regulation of intestinal immunity and further integrate immune response of distal mucosal tissue. Metabolites, especially derived from microbiota, regulate immune cell functions by various ways including recognition and activation of cell surface receptors, controlling of gene expression by epigenetic regulation and integration of cellular metabolism. These mucosal immune regulations are key to understand underlying mechanism for the development of gastrointestinal disorders. Here, we review the recent advancement of our understanding on the role of gut metabolites in the regulation of gastrointestinal immunity with highlighting the cellular and molecular regulatory mechanisms by macronutrients-derived metabolites.
ARTICLE | doi:10.20944/preprints202010.0133.v1
Subject: Biology, Anatomy & Morphology Keywords: Biomarkers; Fatty acid profile; Halogenated compounds; Oxidative stress; Red macroalgae; Secondary metabolites
Online: 6 October 2020 (14:52:20 CEST)
The red seaweed Asparagopsis armata exhibits a strong invasive behaviour and is included in the list of the “Worst invasive alien species threatening biodiversity in Europe”. This seaweed has been shown to produce a large diversity of halogenated compounds with effective biological effects, deeply affecting rockpool species. Therefore, the present study aimed to investigate the biochemical responses to sublethal concentrations of Asparagopsis armata exudate on two coastal organisms, the marine snail Gibbula umbilicalis and the rockpool shrimp Palaemon elegans. Antioxidant defences superoxide dismutase (SOD) and glutathione-S-transferase (GST), oxidative damage endpoints lipid peroxidation (LPO) and DNA damage, the neuronal parameter acetylcholinesterase (AChE), as well as the fatty acid profile were evaluated. Results revealed different metabolic responses between species, indicating that A. armata exudate affected the organisms through different pathways. Despite previous studies indicating that the exudate effected G. umbilicalis’ survival and behaviour, this does not seem to result from oxidative stress or addressed neurotoxicity. On the other hand, for P. elegans, an inhibition of AChE and the decrease of antioxidant capacity concomitant with the increase of LPO, suggests neurotoxicity and oxidative stress as mechanisms of exudate toxicity for this species. For fatty acids, there were different profile changes between species, also more pronounced for P. elegans with a general increase in PUFA with exudate exposure, which commonly means a defence mechanism protecting from membrane disruption. Nonetheless, the omega-3 PUFAs ARA and DPA were increased in both invertebrates, indicating a common mechanism regulation of inflammation and immunity responses to this stress. This work provides further insight on the mechanisms of invertebrate response and tolerance to an expanding coastal environmental stress as is the marine invader A. armata.
ARTICLE | doi:10.20944/preprints202211.0481.v1
Subject: Biology, Plant Sciences Keywords: Cynodon dactylon; Aspergillus flavus; endophytic fungus; secondary metabolites; anticancer; breast cancer; Bcl-2
Online: 25 November 2022 (10:19:48 CET)
Endophytic fungi are a diverse group of microorganisms that colonize the inter- or intracellular spaces of plants for mutual benefits. The interactions with a host plant and other microbiomes are multidimensional and play a crucial role in the production of secondary metabolites. We screened bioactive compounds present in the extracts of Aspergillus flavus, an endophytic fungus isolated from the roots of the medicinal grass Cynodon dactylon, for its anticancer potential. Ethyl acetate extract from isolated A. flavus showed significant cytostatic effects (IC50: 16.25 μg mL−1) against breast cancer cells (MCF-7). Morphology of cells and DAPI stained nuclei along with the results of flow cytometry annexin V/PI assay suggested apoptosis to be the main process leading to cells’ death. While investigating the mechanism that triggers apoptosis, we found that the extract of A. flavus increased ROS generation and caused loss of mitochondrial membrane potential of MCF-7 cells. To identify the metabolites that might be responsible for the anticancer effect, the extract was examined using gas chromatography-mass spectrometry (GC-MS). Interestingly, nine phytochemicals were found to have potential inhibitory effects of anti-apoptotic protein (Bcl-2) in the breast cancer cells. In the in silico molecular docking and molecular dynamics simulation studies revealed that two compounds: 2,4,7-Trinitrofluorenone and 3alpha, 5alpha-Cyclo-ergosta-7,9(11),22t-triene-6beta-ol exhibited significant binding affinities (-9.20, and -9.50 Kcal mol-1, respectively) against Bcl-2 along with binding stability and intermolecular interactions of its ligand-Bcl-2 complexes. Overall, the study found that the endophytic A. flavus from C. dactylon contains plant-like bioactive compounds that have a promising effect in breast cancer.
Subject: Life Sciences, Biochemistry 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.
REVIEW | doi:10.20944/preprints202005.0342.v1
Subject: Medicine & Pharmacology, Pharmacology & Toxicology Keywords: seaweed; metabolites; neuroprotection; Alzheimer’s disease; Parkinson’s disease; ischemic stroke; computer-aided drug discovery
Online: 21 May 2020 (09:49:29 CEST)
Beyond their significant contribution to the dietary and industrial supplies, marine algae are considered to be a potential source of some unique metabolites with diverse health benefits. The pharmacological properties, such as antioxidant, anti-inflammatory, cholesterol homeostasis, protein clearance and anti-amyloidogenic potentials of algal metabolites endorse their protective efficacy against oxidative stress, neuroinflammation, mitochondrial dysfunction, and impaired proteostasis which are known to be implicated in the pathophysiology of neurodegenerative disorders and the associated complications after cerebral ischemia and brain injuries. As was evident in various preclinical studies, algal compounds conferred neuroprotection against a wide range of neurotoxic stressors, such as oxygen/glucose deprivation, hydrogen peroxide, glutamate, amyloid β, or 1-methyl-4-phenylpyridinium (MPP+) and, therefore, hold therapeutic promise for brain disorders. While a significant number of algal compounds with promising neuroprotective capacity have been identified over the last decades, a few of them have had access to clinical trials. However, the recent approval of an algal oligosaccharide, sodium oligomannate, for the treatment of Alzheimer's disease enlightened the future of marine algae-based drug discovery. In this review, we briefly outline the pathophysiology of neurodegenerative diseases and brain injuries for identifying the targets of pharmacological intervention, and then review the literature on the neuroprotective potentials of algal compounds along with the underlying pharmacological mechanism, and present an appraisal on the recent therapeutic advances. We also propose a rational strategy to facilitate algal metabolites-based drug development.
ARTICLE | doi:10.20944/preprints202001.0113.v1
Subject: Biology, Other Keywords: anthocyanins and metabolites; inflammation; adhesion molecules; vascular endothelial growth factor; monocytes; endothelial cells
Online: 11 January 2020 (14:51:26 CET)
The present study aims to evaluate the ability of peonidin and petunidin-3-glucoside (Peo and Pet-3-glc) and their metabolites (vanillic acid; VA and methyl-gallic acid; MetGA), to prevent monocyte (THP-1) adhesion to endothelial cells (HUVECs), and to reduce the production of VCAM-1, E-selectin and VEGF in a stimulated pro-inflammatory environment, a pivotal step of atherogenesis. Tumor necrosis factor-α (TNF-α; 100 ng mL-1) was used to stimulate the adhesion of labelled monocytes (THP-1) to endothelial cells (HUVECs). Successively, different concentrations of Peo-3-glc and Pet-3-glc (0.02, 0.2, 2 and 20 µM) and VA and MetGA (0.05, 0.5, 5 and 50 µM) were tested. After 24 h, the production of VCAM-1, E-selectin and VEGF was quantified by ELISA kits, while the adhesion process was measured spectrophotometrically. Peo-3-glc and Pet-3-glc (from 0.02 to 20 µM) significantly (p<0.0001) decreased THP-1 adhesion to HUVECs at all concentrations (-37%, -24%, -30% and -47% for Peo-3-glc; -37%, -33%, -33% and -45% for Pet-3-glc). VA, but not MetGA, reduced the adhesion process at 50 µM (-21%; p<0.001). At the same concentrations, a significant (p<0.0001) reduction of E-selectin, but not VCAM-1, was documented. In addition, anthocyanins and their metabolites significantly decreased (p<0.001) VEGF production. The present findings suggest, that while Peo-3-glc and Pet-3-glc, but not their metabolites, reduced monocyte adhesion to endothelial cells through suppression of E-selectin production, VEGF production was reduced by both anthocyanins and their metabolites suggesting a role in regulation of angiogenesis.
ARTICLE | doi:10.20944/preprints201810.0726.v1
Subject: Life Sciences, Other Keywords: oral administration; lactic acid bacteria metabolites; skin barrier function; water content; atopic dermatitis
Online: 30 October 2018 (14:18:16 CET)
The effects of orally administered lactic acid bacteria metabolites on the skin were studied using an atopic dermatitis-like murine model created by feeding mice with HR-AD. The lactic acid bacteria metabolites were obtained by inoculating 35 strains of 16 species of lactic acid bacteria into soy milk and culturing them. The atopic dermatitis-like murine model was created by feeding HR-1 mice HR-AD for 40 days. The skin condition of mice that were fed HR-AD worsened compared with normal mice, i.e., reduced water content in the stratum corneum, increased transepidermal water loss (TEWL), reduced ceramide AP content in the stratum corneum, and increased epidermis thickness. When mice that had been fed the HR-AD diet was administered a raw liquid of lactic acid bacteria metabolites orally, the measured values related to water content in the stratum corneum, TEWL, ceramide AP content in the stratum corneum, and epidermis thickness improved. To find out the active components for these effects, filtrate and residue from the raw liquid of lactic acid bacteria metabolites and lipid components extracted from the raw liquid were examined at the same time. Results showed that the water-soluble components or residue after filtration did not demonstrate effects but the raw liquid and the lipid fraction did. These findings suggest that lactic acid bacteria metabolites improve skin injury in an atopic dermatitis-like murine model.
REVIEW | doi:10.20944/preprints202111.0175.v1
Subject: Biology, Other Keywords: atherosclerotic cardiovascular disease (ACVD); atherosclerosis; gut dysbiosis; immune system; gut microbial metabolites; SCFAs; TMAO
Online: 9 November 2021 (13:45:20 CET)
Atherosclerosis is a leading cause of cardiovascular disease and mortality worldwide. Alterations in the gut microbiota composition, known as gut dysbiosis, have been shown to contribute to atherosclerotic cardiovascular disease (ACVD) development through several pathways. Disruptions in gut homeostasis are associated with activation of immune processes and systemic inflammation. The gut microbiota produces several metabolic products, namely trimethylamine (TMA), which is used to produce the proatherogenic metabolite trimethylamine-N-oxide (TMAO). Short chain fatty acids (SCFAs), including acetate, butyrate, and propionate, and certain bile acids (BAs) produced by the gut microbiota lead to inflammation resolution and decrease atherogenesis. Chronic low-grade inflammation is associated to common risk factors for atherosclerosis, including metabolic syndrome, type 2 diabetes mellitus (T2DM), and obesity. Novel strategies for reducing ACVD include the use of nutraceuticals such as resveratrol, modification of glucagon-like peptide 1 (GLP-1) levels, supplementation with probiotics, and administration of prebiotic SCFAs and BAs. Investigation into the relationship between the gut microbiota and its metabolites, and the host immune system could reveal promising insight into ACVD development, prognostic factors, and treatments.
ARTICLE | doi:10.20944/preprints202107.0315.v1
Subject: Chemistry, Analytical Chemistry Keywords: Myxobacteria; myxochelin; nicotinic acid; secondary metabolites; natural product discovery; precursor-directed biosynthesis; total synthesis
Online: 14 July 2021 (10:03:32 CEST)
Myxobacteria represent a viable source of chemically diverse and biologically active secondary metabolites. The myxochelins are a well-studied family of catecholate-type siderophores produced by various myxobacterial strains. Here, we report the discovery, isolation and structure elucidation of three new myxochelins N1–N3 from the terrestrial myxobacterium Corallococcus sp. MCy9049, featuring an unusual nicotinic acid moiety. Precursor-directed biosynthesis (PDB) experiments and total synthesis were performed in order to confirm structures, improve access to pure compounds for bioactivity testing and to devise a biosynthesis proposal. The combined evaluation of metabolome and genome data covering myxobacteria supports the notion that the new myxochelin congeners reported here are in fact frequent side products of the known myxochelin A biosynthetic pathway in myxobacteria.
ARTICLE | doi:10.20944/preprints202009.0251.v1
Subject: Biology, Physiology Keywords: Trichoderma atroviride; mycoparasitism; secondary metabolites; 6-pentyl-alpha-pyrone; Tmk3 MAP kinase; light; dark
Online: 11 September 2020 (08:49:15 CEST)
The ascomycete Trichoderma atroviride is well known for its mycoparasitic lifestyle. Similar to other organisms, light is an important cue for T. atroviride. However, besides triggering of conidiation, little is known on the physiological responses of T. atroviride to light. In this study, we analyzed how cultivation under different light wavelengths and regimes impacted the behavior of two T. atroviride wild-type strains, IMI206040 and P1. While colony extension of both strains was slightly affected by light, massive differences in the photoconidation response between the two strains became evident. T. atroviride P1 colonies conidiated under all conditions tested including growth in complete darkness, while IMI206040 required white, blue or green light to trigger asexual reproduction. Interestingly, deletion of the stress-activated MAP kinase-encoding gene tmk3 abolished the ability of strain P1 to conidiate in red and yellow light as well as in darkness. Furthermore, light-dependent differences in the mycoparasitic activity of T. atroviride and in the biosynthesis of the secondary metabolite 6-pentyl--pyrone (6-PP) became evident. 6-PP production was highest upon dark incubation while light, especially exposure to white light as light/dark cycles, had an inhibitory effect on its biosynthesis. We conclude that the response of T. atroviride to light is strain-dependent and impacts differentiation, mycoparasitism and 6-PP production and hence should be considered in experiments testing the mycoparasitic activity of these fungi.
ARTICLE | doi:10.20944/preprints202210.0003.v2
Subject: Medicine & Pharmacology, Obstetrics & Gynaecology Keywords: birth weight, birth length, head circumference, placenta weight, growth 43 parameters, polycyclic aromatic hydrocarbons, monohydroxylated PAH metabolites
Online: 6 October 2022 (14:39:33 CEST)
Background and objectives: The impact of prenatal exposure to polycyclicaromatic 17 hydrocarbons (PAHs) on birth outcomes as weight, length, head circumference, placenta 18 weight, and Apgar. Materials and Methods: Two cohorts of children born in the years 2013 and 19 2014 in Karvina (Northern Moravia, N=144) and Ceske Budejovice (Southern Bohemia, 20 N=198), were studied for the relationship between the prenatal exposure to PAHs and growth 21 parameters up to two years of age. PAHs exposure was evaluated according to the concentration 22 of benzo[a]pyrene (B[a]P) in polluted air and monohydroxylated PAH metabolites (OH-PAHs) 23 in urine of newborns as well as their mothers. Data of growth parameters were obtained from 24 pediatric questionnaires up to 24 months. 25 Results: Concentrations of B[a]P were significantly higher in Karvina (p<0.001). OH-26 PAH metabolites were significantly higher in the mothers´ as well as in the newborns´ urine in 27 Karvina. The length was shorter in newborns in Karvina at birth (p<0.001), but this difference 28 was straightened out during next 3 to 24 months. Birth weight at the delivery did not differ 29 between newborns in Karvina and Ceske Budejovice. Newborns in both locations significantly 30 decreased their weight gain between birth and 3 months after delivery. OH-PAHs metabolites 31 in mother’s or newborn’s urine did not affect birth weight. Top 25% values of concentrations 32 of 2-OH-FLUO, 1-OH-NAP, 2-OH-NAP, 1-OH-PHEN, 2-OH-PHEN, 3-OH-PHEN, 4-OH-33 PHEN, and the sum of all-OH-PAHs higher than median in the newborns´ urine decreased their 34 length. 2-OH-PHEN top 25% of concentrations in the newborns´ urine decreased their head 35 circumference, 2-OH-FLUO, 1-OH-NAP, 2-OH-NAP, 1-OH-PHEN, 2-OH-PHEN, 3-OH-36 PHEN, 4-OH-PHEN, 9-OH-PHEN, 1-OH-PYR, and all-OH-PAHs decreased placenta weight; 37 2-OH-FLUO, 1-OH-NAP, 2-OH-NAP, 1-OH-PHEN, 2-OH-PHEN, 3-OH-PHEN, 4-OH-38 PHEN, and all-OH-PAHs decreased Apgar 5´. Conclusions: We observed that higher 39 concentration of PAHs determined as OH-PAHs metabolites in newborns´ urine decreased their 40 length, head circumference, placenta weight, and Apgar 5´, but did not affect birth weight.
REVIEW | doi:10.20944/preprints202110.0354.v1
Subject: Chemistry, Organic Chemistry Keywords: Phorbas; marine sponges; marine natural products (MNPs); bioactivity,; cytotoxic metabolites; antimicrobial and anti-inflammatory activities; sesterterpene
Online: 25 October 2021 (13:16:55 CEST)
Porifera, commonly referred to as marine sponges, have stood out as major producers of marine natural products (MNPs). Sponges of the genus Phorbas have attracted much attention along years. They are widespread in all continents, and several structurally unique compounds have been identified from species of this genus. Terpenes, mainly sesterterpenoids, represent the great majority of secondary metabolites isolated from Phorbas species, even though several alkaloids and steroids have also been reported. Many of these compounds have shown a variety of biological activities. Particularly, Phorbas sponges have been demonstrated to be a source of cytotoxic metabolites. In addition, MNPs exhibiting cytostatic, antimicrobial and anti-inflammatory activities, have been isolated and structurally characterized. This work brings an overview of Phorbas secondary metabolites reported since the first study published in 1993 until 2020, and their biological activities.
ARTICLE | doi:10.20944/preprints202104.0390.v1
Subject: Life Sciences, Biochemistry Keywords: redox metabolites; mass-spectrometry method; HILIC chromatography; NADH; NADPH; Glutathione; redox metabolite detection in mammalian cells
Online: 14 April 2021 (16:09:16 CEST)
Cellular redox state is highly dynamic and delicately balanced between constant production of reactive oxygen species (ROS), and neutralization by endogenous antioxidants, such as glutathione. Physiologic ROS levels can function as signal transduction messengers, while high levels of ROS can react with and damage various molecules eliciting cellular toxicity. The redox state is reflective of the cell’s metabolic status and can inform on regulated cell-state transitions or various pathologies including aging and cancer. Therefore, methods that enable reliable, quantitative readout of the cellular redox state are imperative for scientists from multiple fields. Liquid-chromatography mass-spectrometry (LC-MS) based methods to detect small molecules that reflect the redox balance in the cell such as glutathione, NADH and NADPH, have been developed and applied successfully, but because redox metabolites are very labile, these methods are not easily standardized or consolidated. Here we report a robust LC-MS method for the simultaneous detection of several redox-reactive metabolites that is compatible with parallel global metabolic profiling in mammalian cells. We performed a comprehensive comparison between three commercial hydrophilic interaction chromatography (HILIC) columns, and we describe the application of our method in mammalian cells and tissues. The presented method is easily applicable and will enable the study of ROS function and oxidative stress in mammalian cells by researchers from various fields.
ARTICLE | doi:10.20944/preprints202103.0001.v1
Subject: Life Sciences, Biochemistry Keywords: non-alcoholic fatty liver disease; xylo-oligosaccharides; metabolites; gut microbiota; biclustering; high fat diet; microRNAs; rats
Online: 1 March 2021 (12:28:31 CET)
We have shown that prebiotic xylo-oligosaccharides (XOS) increased beneficial gut microbiota (GM) and prevented high fat diet-induced hepatic steatosis, but the mechanisms behind these effects are not clear. We studied whether XOS affects adipose tissue inflammation and insulin signaling, and whether the GM and fecal metabolome explain associated patterns. XOS was supplemented or not with high (HFD) or low (LFD) fat diet for 12-weeks in male Wistar rats (n = 10/group). Previously analyzed GM and fecal metabolites were biclustered to reduce data dimensionality and identify interpretable groups of co-occurring genera and metabolites. Based on our findings, biclustering provides a useful algorithmic method for capturing such joint signatures. On the HFD, XOS-supplemented rats showed lower number of adipose tissue crown-like structures, increased phosphorylation of AKT in liver and adipose tissue as well as lower expression of hepatic miRNAs. XOS-supplemented rats had more fecal glycine and less hypoxanthine, isovalerate, branched chain amino acids and aromatic amino acids. Several bacterial genera were associated with the metabolic signatures. In conclusion, the beneficial effects of XOS on hepatic steatosis involved decreased adipose tissue inflammation and likely improved insulin signaling, which were further associated with fecal metabolites and GM.
ARTICLE | doi:10.20944/preprints201907.0290.v1
Subject: Life Sciences, Biotechnology Keywords: Irreversible electroporation, microfluidics, microelectrodes, pulsed electric field electroporation, intracellular metabolites, enzymes, quenching, E. coli, S. cerevisiae
Online: 25 July 2019 (11:44:33 CEST)
Exploring the dynamic behavior of cellular metabolism requires a standard laboratory method that guarantees rapid sampling and extraction of the cellular content. We propose a versatile sampling technique applicable to cells with different cell wall and cell membrane properties. The technique is based on irreversible electroporation with simultaneous quenching and extraction by using a microfluidic device. By application of electric pulses in the millisecond range, permanent lethal pores are formed in the cell membrane of Escherichia coli and Saccharomyces cerevisiae, facilitating the release of the cellular contents; here demonstrated by the measurement of glucose-6-phosphate and the activity of the enzyme glucose-6-phosphate dehydrogenase. The successful application of this device was demonstrated by pulsed electric field treatment in a flow-through configuration of the microfluidic chip in combination with sampling, inactivation, and extraction of the intracellular content in a few seconds. Minimum electric field strengths of 10 kV/cm for E. coli and 7.5 kV/cm for yeast S. cerevisiae were required for successful cell lysis. The results are discussed in the context of applications in industrial biotechnology, where metabolomics analyses are important.
ARTICLE | doi:10.20944/preprints202008.0623.v1
Subject: Life Sciences, Microbiology Keywords: Leptospermum scoparium; Cryptomeria japonica; Mānuka; Sugi; Essential oils; Natural products; Secondary metabolites; Antimicrobials; Gas chromatography – Mass spectrometry
Online: 27 August 2020 (14:13:24 CEST)
This study evaluated the antimicrobial activity of Leptospermum scoparium (Mānuka) and Cryptomeria japonica (Sugi) essential oils and assessed the effect of seasonal chemical variation on the oils’ antimicrobial efficacies. Plate based assays were conducted to elucidate the oils’ spectrum of in vitro antimicrobial activity and to determine the oils’ minimum inhibitory concentrations (MIC) as a measure of antimicrobial efficacy. Gas chromatography – mass spectrometry was adopted to chemically profile oils distilled in different seasons. The resultant compositional information in conjunction with MIC data was used to evaluate the effect of seasonal variation on the oils’ antimicrobial efficacy. Both Mānuka and Sugi essential oils were active against all classes of target microorganisms. However, limited activity was observed against Gram-negative bacteria. The oils displayed consistent chemotypic characteristics regardless of the time of distillation. Nonetheless, there were quantitative differences in compound abundance in both essential oils. Significant differences in the MIC of Sugi essential oil was observed against target microorganisms as a result of seasonal variation in constituent abundances while Mānuka essential oil’s antimicrobial efficacy was unaffected. This study demonstrates that seasonal chemical variation is an important quality assurance parameter to consider for future application of essential oils as antimicrobial agents in consumer products.
REVIEW | doi:10.20944/preprints201804.0060.v1
Subject: Materials Science, Surfaces, Coatings & Films Keywords: volatile renewable resources; microbial infection; secondary plant metabolites; antimicrobial essential oils; biologically-active polymers; plasma-assisted technique
Online: 5 April 2018 (03:32:08 CEST)
The persistent issue of bacterial and fungal colonization of artificial implantable materials and decreasing efficacy of conventional systemic antibiotics used to treat implant-associated infections has led to the development of a wide range of antifouling and antibacterial strategies. This article reviews one such strategy where inherently biologically active renewable resources, i.e. secondary plant metabolites (SPMs) and their naturally occurring combinations (i.e. essential oils) are used for surface functionalization and synthesis of polymer thin films. With a distinct mode of antibacterial activity, broad spectrum of action and diversity of available chemistries, secondary plant metabolites present an attractive alternative to conventional antibiotics. However, their conversion from liquid to solid phase without significant loss of activity is not trivial. Using select examples, this article shows how plasma techniques provide a sufficiently flexible and chemically reactive environment to enable the synthesis of biologically-active polymer-coatings from volatile renewable resources.
ARTICLE | doi:10.20944/preprints202204.0248.v1
Subject: Life Sciences, Molecular Biology Keywords: granulosa cells; heat stress; integrated analysis; transcriptomics; metabolomics; differentially ex-pressed genes; metabolites; signaling pathways; metabolic pathways; cancer pathways
Online: 27 April 2022 (05:08:15 CEST)
Previous studies reported the physical, transcriptomics and metabolomics changes in in-vitro acute heat stressed bovine granulosa cells. Granulosa cells exhibited transient proliferation senescence, oxidative stress, increased rate of apoptosis, and decline in steroidogenic activity. This study performs joint integration and network analysis of metabolomics and transcriptomics data to further narrow down and elucidate the role of differentially expressed genes, important metab-olites and relevant cellular and metabolic pathways in acute heat-stressed granulosa cells. Among significant (Raw P-value <0.05) metabolic pathways where metabolites and genes did converge, this study found Vitamin B6 metabolism, Glycine, serine and threonine metabolism, Phenylalanine metabo-lism, Arginine biosynthesis, Tryptophan metabolism, Arginine and proline metabolism, Histidine metabolism, and Glyoxylate and dicarboxylate metabolism. Important significant convergent bio-logical pathways included, ABC transporters and Protein digestion and absorption, while func-tional signaling pathways included cAMP, mTOR, and AMPK signaling pathways together with Ovarian steroidogenesis pathway. Among caner pathways, the most important pathway was Central carbon metabolism in cancer. Through multiple analysis query, Progesterone, Serotonin, citric acid, Pyridoxal, L-Lysine, Succinic acid, L-Glutamine, L-Leucine, L-Threonine, L-Tyrosine, Vitamin B6, Choline, and CYP1B1, MAOB, VEGFA, WNT11, AOX1, ADCY2, ICAM1, PYGM, SLC2A4, SLC16A3, HSD11B2 and NOS2 appeared to be important enriched metabolites and genes, respectively. These genes, metabolites, metabolic, cellular and cell signaling pathways com-prehensively elucidate the mechanisms underlying the intricate fight between death and survival in acute heat-stressed bovine granulosa cells, and essentially help further our understanding and future quest of research in this direction.
Subject: Biology, Other Keywords: trichoderma atroviride; mycoparasitism; secondary metabolites; volatile organic compounds (VOCs); photoconidiation; fungi; 2-octanone; injury response; light response; fusarium oxysporum
Online: 11 December 2019 (04:55:05 CET)
Trichoderma atroviride is a strong necrotrophic mycoparasite antagonizing and feeding on a broad range of fungal phytopathogens. It further beneficially acts on plants by enhancing growth in root and shoot and inducing systemic resistance. Volatile organic compounds (VOCs) are playing a major role in all those processes. To date, T. atroviride IMI 206040 and T. atroviride P1 are among the most frequently studied T. atroviride strains and hence are used as model organisms to study mycoparasitism and photoconidiation. However, there are no studies available, which systematically and comparatively analyzed putative differences between these strains regarding their light-dependent behavior. We therefore explored the influence of light on conidiation and the mycoparasitic interaction as well as the light-dependent production of VOCs in both strains. Our data show that in contrast to T. atroviride IMI 206040 conidiation in strain P1 is independent of light. Furthermore, significant strain-and light-dependent differences in the production of several VOCs between the two strains became evident, indicating that T. atroviride P1 could be a better candidate for plant protection than IMI 206040.
ARTICLE | doi:10.20944/preprints202209.0192.v1
Subject: Life Sciences, Biochemistry Keywords: soy protein isolate; protein hydrolysate; soy protein peptides; physical load; food efficacy and safety; NMR blood test; blood metabolites; forced swimming
Online: 14 September 2022 (04:57:19 CEST)
Peptides of hydrolysates of food proteins are an easily digestible source of amino acids necessary for the body to adapt to physical stress. Commercially significant hydrolysates include whey protein, casein, and other animal proteins. Hydrolysates of plant proteins are gaining popularity, but they are less common, then animal ones. Soy protein isolate is promising for obtaining the hydrolysates due to its affordable price and balanced amino acid profile. However, there are no direct studies showing an improvement in the result of physical activity when eating soy protein isolate hydrolysate (SPIH). In this work, for the first time, the study was conducted on the safety and efficacy of SPIH during physical load on model animals (rats). It was shown that the hydrolysate did not lead to pathological changes in the viscera, food intake, and weight of animals did not differ from the control group (animals consumed whey protein). Under physical load rats enteral fed SPIH showed a tendency to adapt more quickly to physical stress than the control group and the group of animals that was fed by free amino acids. The metabolites of animal blood serum were studied by NMR spectroscopy. It was shown that by the 95th minute after feeding in the group of rats receiving SPIH, the difference of proteinogenic amino acids concentrations in blood between individuals was significantly less than in the groups receiving whey protein or a mixture of amino acids. In other words, individual biochemical and physiological characteristics of individuals did not affect the assimilation of amino acids of hydrolysate.
ARTICLE | doi:10.20944/preprints202201.0433.v1
Subject: Behavioral Sciences, Behavioral Neuroscience Keywords: cohousing; stress; CD1 mouse; C57BL/6J mouse; Sprague Dawley rat; fecal corticosterone or cortisol metabolites; dyadic social interaction; conditioned place preference
Online: 28 January 2022 (11:13:58 CET)
Rats, including those of the Sprague Dawley strain, may kill mice. Because of this muridical behavior, it is standard practice in many research animal housing facilities to separate mice from rats (i.e., the predators) to minimize stress for the mice. We therefore tested the effect of cohousing on the stress levels of mice from either the C57BL/6J (BL6) or the CD1 strain and Sprague Dawley (SD rat) by determining their fecal corticosterone or cortisol metabolites (FCM) concentration and investigated how cohousing impacts a behavioral assay, i.e., conditioned place preference for intragenus (i.e., mouse-mouse or rat-rat) dyadic social interaction (DSI CPP) that had been shown be sensitive to social factors, especially to handling by humans. We found that the two delivery batches of BL6 mice or SD rats, respectively, had different stress levels at delivery that were statistically significant for the BL6 mice. Even so, the BL6 mice cohoused with rats had significantly increased FCM concentrations, indicative of higher stress levels, as compared to (1) BL6 mice housed alone or (2) BL6 mice at delivery. In contrast to their elevated stress levels, the attractiveness for contextual cues associated with mouse-mouse social interaction (DSI CPP) even increased in rat-cohoused BL6 mice, albeit nonsignificantly. Thus, cohousing BL6 mice and rats did not impair a behavioral assay in BL6 mice that had proved to be sensitive to handling stress by humans in our laboratory. SD rats cohoused with BL6- or CD1 mice and CD1 mice cohoused with SD rats showed DSI CPP that was not different from our previously published data on SD rats and BL6 mice of the Jackson- or NIH substrain obtained in the absence of cohousing. Our findings suggest that the effect of cohousing rats and mice under the conditions described above on their stress levels as opposed to their behavior might be less clearcut than generally assumed and might be overriden by conditions that cannot be controlled, i.e., different deliveries. Our findings can help to use research animal housing resources, which usually are limited, more efficiently.
Subject: Chemistry, Analytical Chemistry Keywords: 17α-methyl steroids; long-term metabolites; gas chromatography-mass spectrometry; 17-hydroxymethyl-17-methyl-18-nor; D-ring alteration; doping control; metabolism
Online: 1 March 2021 (13:19:54 CET)
Metandienone and methyltestosterone are orally active anabolic-androgenic steroids with a 17α-methyl structure that are prohibited in sports but are frequently detected in anti-doping analysis. After the previously reported detection of long-term metabolites with a 17ξ-hydroxymethyl-17ξ-methyl-18-nor-5ξ-androst-13-en-3ξ-ol structure in the chlorinated metandienone analog dehydrochloromethyltestosterone (“Oral Turinabol”), in this study we investigated the formation of similar metabolites of metandienone and 17α-methyltestosterone with a rearranged D-ring and a fully reduced A-ring. Using a semi-targeted approach including synthesis of reference compounds, two diastereomeric substances, viz. 17α-hydroxymethyl-17β-methyl-18-nor-5β-androst-13-en-3α-ol and its 5α-analog, were identified following an administration of methyltestosterone. In post-administration urines of metandienone, only the 5β-metabolite was detected. Additionally, 3α,5β-tetrahydro-epi-methyltestosterone was identified in the urines of both administrations besides the classical metabolites included in the screening procedures. Besides their applicability for anti-doping analysis, the results provide new insights on the metabolism of 17α-methyl steroids with respect to the order of reductions in the A-ring, the participation of different enzymes, and alterations of the D-ring.