Ulososides and Urabosides — Triterpenoid Saponins from the Caribbean Marine Sponge Ectyoplasia ferox

Abstract

Three new triterpene glycosides, named ulososide F ( 1), urabosides A ( 2) and B ( 3), together with the previously reported ulososide A ( 4), were isolated from the Caribbean marine sponge Ectyoplasia ferox. Their structures were elucidated using extensive interpretation of 1D and 2D-NMR data, as well as HRESIMS. The aglycon of all compounds is a rare 30-norlonastane and the sugar residues were identified after acid hydrolysis and GC analyses. Cytotoxicities of the isolated compounds were evaluated against Jurkat and CHO cell lines by a MTT in vitro assay as well as a hemolysis assay. Unexpectedly, all these saponin derivatives showed very low activity in our bioassays.