STARFISH SAPONINS .23. STEROIDAL GLYCOSIDES FROM THE STARFISH HALITYLE-REGULARIS

Eight new steroidal glycosides were isolated from the starfish H. regularis. Three compds. contain the 2,4-di-O-methyl-β-D-xylopyranosyl-(1→2)-α-L-arabinofuranosyl disaccharide moiety, which is attached at C-24 of polyhydroxysteroid aglycons. Another 3 glycosides have polyhydroxylated 24-(β-hydroxyethyl) steroid aglycons with the disaccharide moieties, 2-O-methyl-β-D-xylopyranosyl-(1→2)-β-D-xylopyranosyl or 2,4-di-O-methyl-β-D-xylopyranosyl-(1→2)-α-L-arabinofuranosyl, located at the primary hydroxyl group at C-29. Unlike the other compds., the other 2 glycosides have a sulfate group. These glycosides are accompanied by 2 nonglycosidated polyhydoxylated sterols, i.e., (25S)-5α-cholestane-3β,6α,8,15β,26-hexol and (25S)-5α-cholestane-3β,4β,6α,8,15β,26-heptol. The structures of the new metabolites were detd. by interpretation of spectral data, comparison with related glycosides described previously, and chem. transformations