Eremophilane sesquiterpenes from the endophytic fungus Xylaria sp. GDG-102

A new eremophilane sesquiterpene, xylareremophil (1), together with five known eremophilanes, 1 alpha,10 alpha-epoxy-3 alpha-hydroxyeremophil-7(11)-en-12,8 beta-olide (2), 1,10 alpha,13-trihydroxyeremophil-7(11)-en-12,8-olide (3), 1 alpha,10 alpha-epoxy-13-hydroxyeremophil-7(11)-en-12,8 beta-olide (4), mairetolides B (5) and G (6) were isolated from the endophytic fungus Xylaria sp. GDG-102 cultured from Sophora tonkinensis. Their structures were elucidated on the basis of spectroscopic data analysis. The absolute configurations of 1 was determined by comparing computed electronic circular dichroism (ECD) and optical rotation (OR) with experimental results. Compounds 1, 5 and 6 showed antibacterial activities against Proteus vulgaris, Micrococcus luteus, Micrococcus lysodeikticus and Bacillus subtilis with MIC values of 25-100 mu g/mL. [GRAPHICS] .