Glycosides of marine invertegrates. XI. Two new triterpene glycosides from holothurians of the familyStichopadidae

By repeated column chromatography on silica gel new glycosides have been isolated from the holothuriansAstichopus multifidus andStichopus chloronotus — astichoposide C and stichoposide C (I and II, respectively). Their structures have been studied with the aid of chemical and physicochemical methods. The complete structures of the glycosides have been established as 23(S)-acetoxy-3β-{4′-O-O-(3-O-methyl-β-D-glucopyranosyl)-(1→3)-β-D-glucopyranosyl]-2′-O-O-(3-O-methyl-β-D-glucopyranosyl)-(1→3)-O-β-D-xylopyranosyl-(1→4)-β-D-quinovopyranosyl]-β-D-xylopyranosyloxy}holosta-7,25-diene and -holost-7-ene.