Ectyoplasides A-B, Unique Triterpene Oligoglycosides from the Caribbean Sponge Ectyoplasia ferox.

Two novel norlanostane triglycosides, ectyoplasides A (1) and B (2), have been isolated from the methanolic extracts of the Caribbean sponge Ectyoplasia ferox (Raspaliidae, Axinellida). Their structures have been established by extensive application of high-resolution FABMS and two- dimensional NMR techniques, supported by chemical and enzymatic degradation methods. Ectyoplasides A and B have been shown to possess identical sugar chains (composed of two β-galactose units and one α-arabinose unit), but to differ in their aglycone moieties, which possess nortriterpene skeletons with an unprecedented substitution pattern on ring A. Ectyoplasides A and B show moderate cytotoxic activity when tested in vitro towards various cell lines.