A new rare asteriscane sesquiterpene and other related derivatives from the Hainan aeolid nudibranch Phyllodesmium magnum

Chemical analysis of the secondary metabolite pattern of the aeolid nudibranch Phyllodesmium magnum collected from the South China sea resulted in the isolation of eight sesquiterpenes, exhibiting very different structural features, which included one asteriscane (1), two africanane (2, 3), one elemane (4), two selinane (5, 6), and two furano- (7,8) sesquiterpenes. Among them, compound 1, a new molecule, represents the fourth example of a rare asteriscane skeleton from a natural source, and the seven known sesquiterpenes (2-8) are new for P. magnum. The occurrence of the metabolites possessed by Phyllodesmium guamensis supports recent chemecological studies that it preys on the soft coral Sinularia sp., and uses these dietary chemicals as its defensive weapon. (C) 2011 Elsevier Ltd. All rights reserved.