STARFISH SAPONINS .43. STRUCTURES OF 2 NEW SULFATED STEROIDAL FUCOFURANOSIDES (IMBRICATOSIDE-A AND IMBRICATOSIDE-B) AND 6 NEW POLYHYDROXYSTEROIDS FROM THE STARFISH DERMASTERIAS-IMBRICATA

Two new sulfated steroidal glycosides, imbricatoside A [1] and imbricatoside Β [2], which inhibited cell division of fertilized sea urchin eggs, have been isolated from the H20 extracts of the whole bodies of the starfish Dermasterias imbricata. They contain the same disaccharide chain, i.e., 2,4-di-0-methyl-β-D-quinovopyranosyl-(1↦2)-5-0-sulfate-β-D-fucopyranosyl, which is linked to C-24 of 5α-cholestane-3β,4β,6α,7α,8,15β,24-heptaol and 5α-cholestane-3ß,6α,7α,8,15β,24-hexaol aglycones. The extracts also contained six new polyhydroxysteroids, to which the structures 3-8 were assigned. Compound 8, (22E,24R)-5α-cholest-22-ene-3β,6α,8,5 β,24-pentaol, showed strong antifungal activity and also inhibited cell division of fertilized sea urchin eggs. © 1990, American Chemical Society. All rights reserved.