Marine natural products. VIII. Bioactive triterpene-oligoglycosides from the sea cucumber Holothuria leucospilota Brandt (2). Structure of holothurin A.

The chemical structure of holothurin A, the major lanostane-type triterpene oligoglycoside from the Cuvierian tubules of the sea cucumber Holothuria leucospilota BRANDT (=H. vagabunda SELENKA), has been elucidated to be 3-O-[β-D-3-O-methylglucopyranosyl-(1→3)-β-D-glucopyranosyl (1→4)-β-D-quinovopyranosyl (1→2)-β-D-xylopyranosyl]-holothurigenol 4'-O-sodium sulfate (8), on the basis of chemical, physicochemical, and biochemical evidence. Holothurin A (8) corresponds to the 4"-O-[3'''-O-(β-D-3''''-O-methyl-glucopyranosyl)-β-D-glucopyranoside] of holothurin B (6), which is the major oligoglycoside of the body walls of the same sea cucumber.