Malabanones A and B, novel nortriterpenoids from Ailanthus malabarica DC

Novel octanor- and nonanor-triterpenoids, malabanones A (1) and B (2), which incorporate a unique tricyclo[4.3.1.01,6]decane unit in the structure, were isolated from the stem bark of Ailanthus malabarica DC. Their structures were elucidated by the analysis of spectral data. Compounds 1 and 2 were considered to be biosynthesized from ailanthol (3), which was also isolated from this plant.