Phenolic Bisabolanes from the Marine-Derived Fungus Aspergillus sp. MEA11

The deep sea sediment-derived fungus Aspergillus sp. MEA11 was examined for secondary metabolites. Chromatographic separations resulted in the identification of a new phenolic bisabolane (1) and seven known analogs (3-7 and 8a, 8b). The structures were determined by H-1, C-13 NMR, and MS data. The known compounds were identified to be 11,12-dihydroxysydonic acid (2), hydroxysydonic acid (3), aspergoterpenin B (4), engyodontiumone J (5), sydowic acid (6), penicipyran A (7), 1-hydroxyboivinianic acid (8). The NMR data of 7 in methanol-d(4) were reported for the first time. Compounds 6-8 exhibited inhibitory effect against alpha-glucosidase with IC50 values of 176, 89, 232 mu M, respectively, which were more active than the positive control acabose.