A novel metabolite from the hybrid soft coral Sinularia maxima × Sinularia polydactyla: a biosynthetically mixed skeleton linking cembrane and africanane terpenoids

A novel terpenoid, polymaxenolide, has been isolated from the hybrid soft coral Sinularia maxima × Sinularia polydactyla. The structure and stereochemistry were determined using spectroscopic methods and X-ray diffraction analysis. This terpenoid with a biosynthetically mixed skeleton is characterized by a C,C-linkage between a cembrane-type diterpene and an africanane-type sesquiterpene. A possible biogenesis is proposed.