Studies on the Constituents of Ophiopogonis Tuber. II. On the Structure of Ophiopogonin B

Abstract

The chemical structure of ophiopogonin B, C₃₉H₆₂O₁₂·2H₂O, mp 269-271°, [α]¹⁵_D-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 (1_rham→2_fuc)-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.