Marine Sterols: XXII: 1) Occurrence of 3-Oxo-4,6,8(14)-triunsaturated Steroids in the Sponge Dysidea herbacea

Abstract

Ten 3-oxo-4,6,8(14)-triunsaturated steroids with cholestane (1,2), ergostane (3,4,5,7) and stigmastane skeletons (6,8,9,10), were isolated from a sponge, Dysidea herbacea, collected off the coast of the Lakshadweep Islands, Indian Ocean. Of these, 7 to 10 were obtained as C-24 epimeric mixtures. Compound 2 had previously been reported from a sponge, Dictyonella insica. The hydroperoxide 10 was shown to be an artefact formed from the 24-ethylidene derivative 6 during storage. The structures of 1 to 10 were derived from spectroscopic evidence. © 1992, The Pharmaceutical Society of Japan. All rights reserved.