linoleic-acid and n-hexane

The antimicrobial activity of endophytic fungi isolated from Euphorbia milii was evaluated against Gram-positive, Gram-negative bacteria, unicellular yeast, and filamentous fungi. Chaetomium ovatoascomatis NRC was identified morphologically and genetically as the most active strain. The total ethyl acetate extract of C. ovatoascomatis NRC demonstrated significant antimicrobial activity against Gram-negative; Escherichia coli, Salmonella enteric, and fungi; Aspergillus niger with MIC of 62.5 ug/ml. Whereas n-hexane fraction demonstrated broader activity against Gram-positive; Bacillus subtilis, Lactobacillus cereus, Gram-negative; Escherichia coli and Salmonella enteric, fungi; Candida albicans and F. solani. LC-MS/MS analysis of ethyl acetate strain extract and GC-MS analysis of the n-hexane fraction were used to identify the metabolites of the strain extract. LC-MS/MS determined three major metabolites with potential antimicrobial activities including grevilline B, aflatoxin G2 and apigenin. GC-MS analysis of n-hexane fraction tentatively identified 30 compounds, where 9,12-octadecadienoic acid methyl ester was the major compound.

Topics: Acetates; Anti-Infective Agents; Apigenin; Bacillus subtilis; Chaetomium; Chromatography, Liquid; Endophytes; Escherichia coli; Esters; Euphorbia; Gas Chromatography-Mass Spectrometry; Gram-Negative Bacteria; Hexanes; Linoleic Acid; Microbial Sensitivity Tests; Phytochemicals; Tandem Mass Spectrometry

We re-examined the antioxidative mechanism of allicin as a radical scavenger on the basis of the reactivity toward 2, 2-diphenyl-1-picrylhydrazyl (DPPH) and peroxyl radicals. Initially, it was found that allicin decomposed more rapidly in n-hexane and chlorobenzene than in acetonitrile, ethanol, and ethanol/water solutions and decomposed into ajoene and vinyldithiins in these solvents. Furthermore, the decomposition of allicin and the following formations of ajoene and vinyldithiins from allicin were accelerated by the reaction of allicin with DPPH and peroxyl radicals. These results show that 2-propenesulfenic acid, which arises by Cope elimination from allicin, is proposed to contribute to scavenge these radicals because ajoene and vinyldithiins were produced from allicin through the use of 2-propenesulfenic acid. Next, allicin was more effective at inhibiting the linoleic acid oxidation at 50 °C than at 30 °C and in cyclohexane than in acetonitrile. These results indicate that allicin decomposed rapidly at high temperatures in a hydrogen-bond-acceptor solution to 2-propenesulfenic acid. In addition, 2-propene-1-sulfinothionic acid S-methyl ester, which does not produce sulfenic acid through Cope elimination, has no activity against the radicals. On the other hand, methanesulfinothionic acid S-2-propenyl ester, which produces methanesulfenic acid through Cope elimination, has the same or increased activity as its allicin against the radicals. Based on these results, the Cope elimination product, sulfenic acid, from thiosulfinates with an α-sulfenyl proton was found to make a larger contribution to the radical scavenger than that of allicin itself.. We examined the antioxidant activity of allicin on the oxidation of cumene and linoleic acid in homogeneous solutions. It is obvious from these results that 2-propenesulfenic acid was found to make a larger contribution to the radical scavenger than that of allicin itself.

Topics: Acetonitriles; Antioxidants; Benzene Derivatives; Chlorobenzenes; Disulfides; Ethanol; Hexanes; Linoleic Acid; Oxidation-Reduction; Sulfenic Acids; Sulfinic Acids; Sulfoxides

Phytochemical investigation of the Rhizopogon luteolus Fr. led to the isolation of one new fatty acid ester, 3-hydroxy-2,4-dimethylheptacosyl acetate (1) together with two known compounds tetracosanoic acid (2) and ergosterol (3). 1D and 2D NMR, and MS techniques were used for structural elucidation. Phenolic and fatty acid compositions were identified using HPLC-DAD and GC-MSD, respectively. Fumaric acid was the major phenolic acid, whereas linoleic, stearic and oleic acids were the most abundant fatty acids. Antioxidant and anticholinesterase activities of the extracts and compounds (1-3) were tested spectrophotometrically. Among the extracts, hexane extract showed the highest activity in all tests, particularly in β-carotene-linoleic acid assay (IC50: 16.65 ± 1.12 μg/mL). Furthermore, compound 3 exhibited higher antioxidant and anticholinesterase activities. The study indicates that R. luteolus can be used in food, cosmetic and pharmaceutical industries.

Topics: Acetates; Agaricales; Antioxidants; beta Carotene; Cholinesterase Inhibitors; Drug Evaluation, Preclinical; Fatty Acids; Fatty Alcohols; Hexanes; Linoleic Acid; Magnetic Resonance Spectroscopy; Molecular Structure; Plant Extracts