Terpenoids with alpha-glucosidase inhibitory activity from the submerged culture of Inonotus obliquus

Two lanostane-type triterpenoids, inotolactones A and B, one drimane-type sesquiterpenoid, inotolactone C, and five known terpenoids, were isolated from the submerged culture of the chaga mushroom, Inonotus obliquus. Inotolactones A and B, two examples of lanostane-type triterpenoids bearing α,β-dimethyl, α,β-unsaturated δ-lactone side-chains, exhibited more potent alpha-glucosidase inhibitory activities than the positive control acarbose.50