Legume Saponins of Gleditsia japonica MIQUEL. IV. ¹³C-Nuclear Magnetic Resonance Spectral Studies for Structure Elucidation of Gleditsia Saponins B and C

Abstract

Two triterpenoid saponins, gleditsia saponins B (GS-B, XIX) and C (GS-C, XX) which were isolated from Gleditsia japonica cv. 'Saponifera', were characterized as 3, 28-O-bisglycosides of echinocystic acid acylated with monoterpene carboxylic acids. On the basis of ¹³C-nuclear magnetic resonance spectra and the results of chemical and enzymatic hydrolysis, it was established that the positions of acylation with the mono-terpenes (IV) and (V) were C-2 and C-3, respectively, of the terminal rhamnose of the 28-O-glycoside moiety in the molecules of GS-C and GS-B.