Bisabolane sesquiterpenes and α-pyrone derivative from endophytic fungus Zopfiella sp

Three undescribed bisabolane sesquiterpenoids, zopfiellins A-C (1-3), and one new alpha-pyrone derivative, zo-fiellone (4), have been isolated from cultures of the endophytic fungus Zopfiella sp. Compound 2 is a rare trinor-bisabolane sesquiterpenoid and 3 has an unusual aromatic core. Compounds 3 and 4 possess mild cytotoxicities against three human cancer cell lines with a range of IC50 values from 12.3-27.3 mu M.