Sesquiterpenes from cultures of the fungus Phellinus igniarius and their Cytotoxicities

Abstract Four new sesquiterpenoids, phellinignins A–D (1–4), together with four known ones (5–8), were isolated from cultures of the fungus Phellinus igniarius. The structures were established by extensive spectroscopic methods including MS, NMR, and the single crystal X-ray diffraction. Compounds 1–3 and 5–8 are tremulane sesquiterpenoids, while compound 4 possesses a new carbon skeleton that might derive from an illudane framework. Compounds 1, 2, 4, and 5 showed certain cytotoxicities to three human cancer cell lines.