Absolute stereostructures of inoterpenes A–F from sclerotia of Inonotus obliquus

Six new lanostane-type triterpenes, inoterpenes A (1), B (2), C (3), D (4), E (5), and F (6), were isolated from the sclerotia of Inonotus obliquus together with six known constituents. The chemical structures of new triterpenes 1–6 were characterized on the basis of chemical and physicochemical evidence including the application of the modified Mosher's method.