Marine Natural Products. XIV. Structures of Echinosides A and B, Antifungal Lanostane-Oligosides from the Sea Cucumber Actinopyga echinites (JAEGER)

Two antifungal lanostane-type triterpene oligosides, named echinosides A (11) and B (9), were isolated from the sea cucumber Actinopyga echinites (JAEGER) collected in Okinawa Prefecture. On the basis of chemical and physicochemical evidence, the structures of echinosides A and B have been elucidated respectively as 3-O-[β-D-3-O-methylglucopyranosyl (1→3)-β-D-glucopyranosyl-(1→4)-β-D-quinovopyranosyl (1→2)-β-D-(4-O-sodiosulfonato) xylopyranosyl]-3β, 12α, 17α, 20 (S)-tetrahydroxy-lanost-9 (11)-en-18, 20-olide (11) and 3-O-[β-D-quinovopyranosyl (1→2)-β-D-(4-O-sodiosulfonato) xylopyranosyl]-3β, 12α, 17α, 20 (S)-tetrahydroxylanost-9 (11)-en-18, 20-olide (9). The antifungal activities of echinosides and allied compounds are discussed.