Study On Secondary Metabolites Of Two Strains Of Staphylococcus Aureus

In this study, two strains of the genus Phomopsis that inhabit different environments (an entomogenous fungus and an endophytic fungus) were cultured to prepare the organic solvent extracts. By application of different separation techniques with various stationary and mobile phases, such as silica gel column chromatography, Sephadex LH-20 column chromatography, and reversed-phase high performance liquid chromatography (RP HPLC),17 secondary metabolites have been isolated from these two strains, and five of them are new compounds belonging to different structural classes. The structures of these new metabolites were elucidated primarily by nuclear magnetic resonance (NMR) and mass spectrometry (MS) techniques. These metabolites were evaluated for the antibacterial activity against a panel of bacteria, fungi, and the plant pathogenic fungi.(+)-S-1-Methyl-abscisic-6-acid (1), (+)-S-Abscisic acid (2), Fusicoccin J (3),3α-Hydroxyfusicoccin J (4), (R)-5-Hydroxymethylmellein (5) and 4-Hydroxyphenethyl acetate (6) were isolated from the fermentation extract of Phomopsis amygdali, an entomogenous fungus isolated from Call midge. Their structures were determined mainly by analysis of their MS and NMR spectroscopic data. Compound (1) is a new sesquiterpene. Compounds 1-4 displayed antibacterial activity against the Gram-negative Pseudomonas aeruginosa 2033E (CGMCC 1.2387) (MIC=26-58μg/mL).2-hydroxy-3-phenylpropyl acetate (1),3-hydroxy-3-phenylpropyl acetate (2),3-phenyl-1,2-propanediol (3),2-(4-hydroxyphenyl)ethanol (4), 2,10-dihydroxyundeca-4,6-dien-1 yl acetamide (5), 5-acetoxy-3-methylpent-2-enoic acid (6),5-hydroxymethylmellein (7), 5-methylmellein (8), p-menthane-1,2,4-triol (9), 3,5-dimethyl-8-methoxy-3,4-dihydroisocoumarin (10), 4-hydroxy-5-methylmellein (11) were isolated from the fermentation extract of Phomopsis amygdali, an endophytic fungus isolated from Illicium verum. Their structures were determined mainly by analysis of their MS and NMR spectroscopic data. Compound 1、2、5 and 6 were new products, compounds 2 displayed antibacterial activity against the Plant pathogenic bacteria Rhizoctonia solani.