Secondary metabolites of the endophytic fungus Myrothecium sp. from Pinellia ternata

Using a series of purification methods including silica gel， Sephadex LH-20 and preparative high performance liquid chromatography， secondary metabolites of Myrothecium sp. were purified from the ethyl acetate extract of the solid fermentation product. Based on structure characterization and investigation on the physical and chemical properties a， twelve monomeric compounds were identified as 3''-hydroxyverrucarin A (1), verrucarin A (2), verrucarin L acetate (3), verrucarin J (4), verrucarin K (5), roridin A (6), roridin D (7), roridin H (8), roridin J (9), verrol 4-acetate (10), (3S, 3aS, 6α, 6aR)-dihydrosporothrioride (11) and 4,6-dihydroxy-1(3H)-isobenzofuranone (12). Compounds 1, 5 and 9 -12 were isolated from Myrothecium sp. for the first time.Compounds 2, 3, 4, 7 and 8 exhibited strong inhibitory effects on Candida albicans, with a minimal inhibitory concentration （MIC₅₀） of 0.318, 0.218, 0.047, 0.569 and 0.558 μg/mL, respectively.