ABSTRACT
The secondary metabolites from the dandelion-derived Epicoccum sorghinum 1-2 were isolated by silica gel and Sephadex gel column chromatography, and semi-preparative high performance liquid chromatography (HPLC). Their structures were identified by comprehensive NMR and MS methods. Their antibacterial activities were determined by filter paper method. Finally, seven compounds were isolated and identified from the fermentation product of E. sorghinum 1-2, including (4R*,5R*,6S*)-4,5-dihydroxy-6-(6'-methylsalicyloxy)-2-methoxymethyl-2-cyclohexen-l-one (1), (4R*,5R*,6S*)-4,5-dihydroxy-6-(6′-methylsalicyloxy)-2-methyl-2-cyclohexen-1-one (2), (4R,5R,6S)-4,5-dihydroxy-6-(6'-methylsalicyloxy)-2-hydroxymethyl-2-cyclohexen-1-one (3), (-)-gabosine E (4), theobroxide (5), 3-chlorogentisyl alcohol (6), and 3-hydroxybenzyl alcohol (7), of which 1-5 are epoxydons, and 6 and 7 are phenolics. Compounds 1 and 2 are new structures reported for the first time. Compound 6 showed significant antibacterial activity against Staphylococcus aureus.
ABSTRACT
One new epoxydon ester (1) and a new benzolactone derivative (2), along with four known compounds (3-6), were isolated from the insect-associated fungus Phoma sp. Their structures were confirmed by extensive MS and NMR spectroscopic analysis and their absolute configurations were determined by a combination of modified Mosher method and Mo2(OCOCH3)4-induced electronic circular dichroism (ECD) experiments. Compounds 1 and 5 were revealed to have potent antioxidant activities, which were approximate to the potency of the positive control trolox. In addition, 1 also exhibited moderate cytotoxic effect against human MGC-803 tumor cell line.[Formula: see text].
