Jaspolides G and H, unique bisisomalabaricanes from the Chinese marine sponge Jaspis sp.

Two unique bisisomalabaricanes jaspolides G (1) and H (2) were isolated from the marine sponge Jaspis sp. Their structures were elucidated on the basis of extensive spectroscopic data (I R, M S, and I D and 2D NMR) analyses. A possible biogenetic pathway via Diels-Alder dimerization for jaspolides G and H was also proposed. (c) 2007 Elsevier Ltd. All rights reserved.