A new drimane sesquiterpenoid and a new triterpene lactone from fungus of Fomes officinalis.
A new sesquiterpenoid fomeffic acid (1) and a new triterpene lactone fomefficinin (2) were isolated from the fungus Fomes officinalis, together with another six known compounds fomitopsin C (3), dehydrosulfurenic acid (4), dehydroeburiconic acid (5), dehydroeburicoic acid (6), 3-keto-dehydrosulfurenic acid (7), and laricinolic acid (8). The structures and stereochemistry of 1 and 2 were determined by NMR and X-ray diffraction analyses. The sesquiterpenoid and five triterpenes were tested for cytotoxicity against HL-60, Bel-7402, and KB cancer lines in vitro, and they appeared to be modestly active.