Constituents of Chinese Crude Drug"Wujiapi."III. On the Structure of Glycoside G and K of Bei-Wujiapi

Abstract

The chemical structure of glycoside G (I), C₃₆H₅₆O₁₃, mp 232-233°, [α]¹⁹_D+30.2°(EtOH) and glycoside K (V), C₄₀H₆₆O₁₆, mp 240-241°, [α]²⁰_D -27.58°(MeOH) were isolated from Bei-Wujiapi (cortex of Periploca sepium B_GE.) and established to be periplocin and Δ⁵-pregnene-3β, 20α-diol(20)-β-D-glucopyranosyl (1_glu→6_glu)-β-D-glucopyranosyl (1_glu→2_dig)-β-D-digitalopyranoside. It should be noted that glycoside K is the first example of the pregnane type glycoside whose sugar moiety links to the hydroxyl group other than C₃-hydroxyl group of the steroidal aglycone.