BIOACTIVE SAPONINS AND GLYCOSIDES .7. ON THE HYPOGLYCEMIC PRINCIPLES FROM THE ROOT CORTEX OF ARALIA-ELATA SEEM - STRUCTURE RELATED HYPOGLYCEMIC ACTIVITY OF OLEANOLIC ACID OLIGOGLYCOSIDE

The hypoglycemic component, elatoside E, was isolated from the root co rtex of Aralia elata SEEM, (Araliaceae) together with elatoside F and eight known oleanolic acid glycosides, elatosides A and C, oleanolic a cid 3-O-[alpha-L-arabinofuranosyl (1-->4)]-beta-D-glucopyranosiduronic acid, oleanolic acid 3-O-beta-D-glucopyranosiduronic acid, stipuleano sides R(1) and R(2), and chikusetsusaponins IV and IVa. The structures of elatosides E and F were determined on the basis of chemical and ph ysicochemical evidence as oleanolic acid 3-O-[beta-D-xylopyranosyl (1- ->2)][beta-D-glucopyranosyl (1-->3)]-alpha-L-arabinopyranoside and its 28-O-beta-D-glucopyranosyl ester, respectively. The hypoglycemic acti vity of oleanolic acid and nine oleanolic acid oligoglycosides from th e root cortex of Al alia elata was determined by monitoring inhibition effect on the elevation of plasma glucose level by oral sucrose toler ance test in rats, and some structure-activity relationships of oleano lic acid glycoside were obtained.