Activation of a Sweet Taste Receptor by Oleanane-Type Glycosides from Wisteria sinensis

The phytochemical study of Wisteria sinensis (Sims) DC. (Fabaceae), commonly known as the Chinese Wisteria, led to the isolation of seven oleanane-type glycosides from an aqueous-ethanolic extract of the roots. Among the seven isolated saponins, two have never been reported before: 3-O-alpha-L-rhamnopyranosyl-(1 -> 2)-beta-D-glucopyranosyl-(1 -> 2)-beta-D-glucuronopyranosyl-22-O-acetylolean-12-ene-3 beta,16 beta,22 beta,30-tetrol, and 3-O-beta-D-xylopyranosyl-(1 -> 2)-beta-D-glucuronopyranosylwistariasapogenol A. Based on the close structures between the saponins from W. sinensis, and the glycyrrhizin from licorice, the stimulation of the sweet taste receptor TAS1R2/TAS1R3 by these glycosides was evaluated.