Studies on the Constituents of Ophiopogonis Tuber. III. On the Structure of Ophiopogonin D

The chemical structure of ophiopogonin B, C39H62O12·2H2O, mp 269-271°, [α]15D-105.5°(pyridine), a main glycoside isolated from the tuber of Ophiopogon japonicus KER-GAWLER var. genuinus MAXIM. (Liliaceae) was established to be ruscogenin (1)-α-L-rhamnopyranosyl (1rham→2fuc)-β-D-fucopyranoside as represented by formula (Ia). It should be noted that ophiopogonin B is one of the examples of the spirostane type glycosides whose sugar moiety links to the hydroxyl group other than C3-hydroxyl group of the aglycone.