Medicinal Foodstuffs. VII. On the Saponin Constituents with Glucose and Alcohol Absorption-Inhibitory Activity from a Food Garnish "Tonburi", the Fruit of Japanese Kochia scoparia (L.) SCHRAD.: Structures of Scoparianosides A, B, and C.

Abstract

The methanolic extract of a food garnish "Tonburi", the fruit of Japanese Kochia scoparia (L.) SCHRAD. (Chenopodiaceae), was found to inhibit the increase in serum glucose in glucose-loaded rats. Through bioassay-guided separation, momordin Ic and its 2'-O-β-D-glucopyranoside were isolated as the active principles from this medicinal foodstuff together with three new saponins named scoparianosides A, B, and C. The structures of scoparianosides A, B, and C were elucidated on the basis of chemical and pysicohemical evidence as 3β, 22α-dihydroxyolean-12-en-28-oic acid (22α-hydroxyoleanolic acid), 3-O-β-D-xylopyranoxyl (1→3)-β-D-glucopyranosiduronic acid, 3β-hydroxyolean-18-en-28-oic acid (morolic acid), 3-O-β-D-xylopyranosy(1→3)-β-D-glucopyranosiduronic acid, and 3β-hydroxyolean-13(8)-en-28-oic acid, 3-O-β-D-xylopyranosyl(1→3)-β-D-glucopyranosiduronic acid.Momordin Ic and its 2'-O-β-D-glucopyranoside, both of which are the principal saponin constituents of this medicinal foodstuff, were found to potently inhibit glucose and ethanol absorption in rats.