Secondary metabolites from the dandelion-derived endophytic fungus Epicoccum sorghinum 1-2

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.