Saponin and Sapogenol. XLVII. On the Constituents of the Roots of Glycyrrhiza uralensis Fischer from Northeastern China. 1. Licorice-Saponins A3, B2, and C2.

From the air-dried root of Glycyrrhiza uralensis, collected in the northeastern part of China, ten new oleanane-type triterpene oligoglycosides were isolated together with glycyrrhizin (1) and several known flavonoids. Among the newly isolated triterpene oligoglycosides, the chemical structures of licorice-saponin A3 (2), licorice-saponin B2 (3), and licorice-saponin C2 (4) have been determined, on the basis of chemical and physicochemical evidence, to be expressed as 30-O-beta-D-glucopyranosylglycyrrhizin, 11-deoxo-glycyrrhizin, and 3-O-[beta-D-glucuronpyranosyl(1-->2)-beta-D-glucuronpyranosyl++ +]oleana- 11,13(18)-dien-30-oic acid, respectively. During the course of these studies, facile conversions from glycyrrhizin (1) to licorice-saponins A3 (2), B2 (3), and C2 (4) have been accomplished.