Stereumins H-J, Stereumane-Type Sesquiterpenes from the Fungus Stereum sp.

Stereumins H (1), I (2), and J (3), three sesquiterpenes possessing a novel stereumane-type backbone, were isolated from an extract of culture broth of the Basidiomycete Stereum sp. CCTCC AF 207024. The complete structural assignments including the absolute configurations are reported by using X-ray studies and density functional theory at the B3LYP/aug-cc-pVDZ//B3LYP/6-31G(d) level.