Prevalence of antimicrobial-resistant bacteria has become a major challenge worldwide. Methicillin-resistant Staphylococcus aureus (MRSA)—a leading cause of infections—forms biofilms on polymeric medical devices and implants, increasing their resistance to antibiotics. Antibiotic administration before biofilm formation is crucial. Raman spectroscopy was used to assess MRSA biofilm development on solid culture media from 0 to 48 h. Biofilm formation was monitored by measuring DNA/RNA-associated Raman peaks and protein/lipid-associated peaks. The search for an antimicrobial agent against MRSA biofilm revealed that Eugenol was a promising candidate as it showed significant potential for breaking down the biofilm. Eugenol was applied at different times to test the optimal time for inhibiting MRSA biofilms, and the Raman spectrum showed that the first 5 h of biofilm formation was the most antibiotic-sensitive time. This study investigated the performance of Raman spectroscopy coupled with Principal Component Analysis (PCA) to identify planktonic bacteria from biofilm conglomerates. Raman analysis, microscopic observation, and quantification of the biofilm growth curve indicated early adhesion from 5 to 10 h of incubation time. Therefore, Raman spectroscopy can help in monitoring biofilm formation on a solid culture medium and performing rapid antibiofilm assessments with new antibiotics during the early stages of the procedure.

In this study, the effect of extraction conditions on the total phenolic content of clove buds was investigated. Clove buds were extracted using a deep eutectic solvents like mixtures choline chloride: lactic acid in the 1:2 molar ratio. Additionally, the HPLC-DAD method was used to determine the main components of the clove extracts, including eugenol, eugenol acetate, and β-caryophyllene. The conditions used in the extraction with choline chloride: lactic acid (molar ratio 1:2) included extraction temperature (t = 40 – 80°C), water addition (5.6 – 40%), and extraction time (30 – 90 min). Determination of the phenolic compounds was done by the Folin-Ciocalteu method. The optimum operating conditions for the total phenolic content were identified at 77°C, 30 min, and a water addition of 40%. Based on the results, the highest amount of eugenol (307.26 ± 8,44 mg/g dry raw material) was determined in clove extracts which were extracted under condition of 60°C, 22.8%, and 30 min.

This study had the objective to evaluate the effect of Piper betle L. powder (PP) at 5 different doses in substrate incubated by sunflower oil as secondary function of PUFA using in vitro gas production technique. The treatments of this study were run as a 2X5 factorial arrangement in a completely randomised design using the PROC GLM procedure of SAS 9.4: (1) control (S1) without supplementation of PP; (2) 15 mg PP (S2); (3) 30 mg PP (S3); (4) 45 mg PP (S4); and (5) 60 mg PP (S5), while sunflower oil was supplemented in all treatments: low 15 mg/incubation and high 30 mg/incubation. A 500 mg of TMR (hay: concentrate, 50:50) was assigned to basal substrate. The PP containing 1.84 mg/g DM quercetin and 1.00 mg/g DM eugenol altered rumen fermentation without change pH (p < 0.001) and methane production was lesser (p < 0.001) about -30% and -25% for DM and OM measurement, respectively. Gas kinetic, degradability, and ammonia level was significantly affected by supplementing PP (p < 0.01). Overall, this study suggested quercetin and eugenol deriving from PP acted three major accelerations: assembled carbon dioxide, behaved antimicrobial role and performed the balance water molecules in the rumen kinetic. This study suggests that PP promotes changing in vitro rumen fermentation and diminishing methane production within recommended doses, 0.1-15 mg/incubation in DM.

The eugenol derivative, ethyl 4-(2-methoxy-4-(oxiran-2-ylmethyl)phenoxy)butanoate 1, with promising insecticidal capability was encapsulated in liposomal formulations of egg-phosphatidylcholine/cholesterol (Egg-PC:Ch) 70:30 and of 100% dioleoylphosphatidylglycerol (DOPG). Compound-loaded Egg-PC:Ch liposomes exhibit small hydrodynamic diameters (below 100 nm), high encapsulation efficiency (88.8% ± 2.7%), higher stability and a more efficient compound release, being chosen for assays in Sf9 insect cells. Compound 1 elicited a loss of cell viability up to 80% after 72h of incubation. Relevantly, encapsulation maintained the toxicity of compound 1 towards insect cells, while it lowered toxicity towards human cells, thus showing the selectivity of the system. Structure based inverted virtual screening was used to predict the most likely targets and molecular dynamics simulations and free energy calculations were used to demonstrate that this molecule can form a stable complex with insect odorant binding proteins and/or acetylcholinesterase.

A new set of alkoxy alcohols were synthesised by reaction of eugenol oxirane with aliphatic and aromatic alcohols. These eugenol derivatives were evaluated against their effect upon the viability of the insect cell line Sf9 (Spodoptera frugiperda).The most promising compounds, 4-(3-(tert-butoxy)-2-hydroxypropyl)-2-methoxyphenol and 4-(2-((4-fluorobenzyl)oxy)-3-hydroxypropyl)-2-methoxyphenol were submitted to in silico assays to predict possible targets. Thought an Inverted Virtual Screening approach, 23 common pesticide targets were screened and the top 2 targets predicted were further evaluated through molecular dynamics simulations and free energy calculations. In addition, these to eugenol derivatives were subjected to encapsulation and release assays using liposome-based nanosystems of egg phosphatidylcholine/cholesterol (7:3), with encapsulation efficiencies higher than 90% and release profiles well described by both Korsmeyer-Peppas and Weibull models.

Finding new ways for the preparation of cross-linked structures is a significant problem in terms of materials for biomedical application, lithium batteries electrolytes, and etc. Within this work we have studied the possibility to utilize hydrosilylation and Piers-Rubinsztajn reactions to obtain cross-linked model phosphazene compounds, containing eugenoxy and guaiacoxy groups. It was shown that Piers-Rubinsztajn reaction cannot be efficiently used to prepare tailored polymer-matrix, due to the catalyst deactivation by nitrogen atoms of phosphazene units. A number of cross-linked phosphazene-based materials was obtained with the use of hydrosilylation reaction and their properties were studied by NMR spectroscopy, FTIR, DSC, and TGA. This work showed a perspective for the use of eugenoxy functional groups for the preparation of three-dimensional hybrid phosphazene/siloxane-based materials for various applications.

The main focus of this work is to extend the knowledge about the complexity of issues of oxidative stress. Natural compounds play a serious role in multiple aspects of both human, leading to clear health-promoting effects. This work is focused on the potential application cosmetic formulations containing including but not limited to of clove water and isolated clove oils on their aid in the control of the diseases. The aim of our work was to prepare to evaluate cosmetic formulations containing clove oil, eugenol or new eugenol ester derivative (eugenyl dichloroacetate - EDChA) but also cosmetic formulations containing the aqueous phase obtained after separation of essential oil following the clove buds steam distillation. To evaluate the antioxidants transdermal delivery system, in vitro permeation experiments in a Franz diffusion cell were performed using pig skin. The antioxidative capacity of the cosmetic formulations obtained was determined by the DPPH free radical reduction method. In the next stage, the antioxidant activity (DPPH, ABTS, and Folin–Ciocalteu methods) of the fluid that penetrated through pig skin and of the fluid obtained after skin extraction, were also evaluated. For comparison, studies of cosmetic formulation containing alone dichloroacetic acid (DChAA) were as well carried out. The obtained cosmetic formulations were characterized by of antioxidant activity estimated after 24 hours of conducting the experiment, which indicates long-term protection against reactive oxygen species (ROS) in the deeper layers of the skin. The results of this work contribute to the development of cosmetic formulations with antioxidant potential, emphasizing that the water phases are waste from the process of cloves steam distillation and are not used to prepare cosmetic formulations. The use of waste water from the clove buds steam distillation process is environmentally friendly and not allows us to waste, containing however valuable biologically active compounds (furfural, methyl salicylate, 4-allilofenol, eugenol, α- and β-caryophyllene, eugenyl acetate, β-caryophyllene oxide). Together, these results suggest that cosmetic formulations may be potential drug candidates for chemopreventive, antineoplastic and antimutagenic therapy.