^<13>C Nuclear Magnetic Resonance Spectral Studies on Gleditsia Saponin C (GS-C)

Abstract

A major triterpenoid saponin (GS-C) of the fruit capsule of Gleditsia japonica MIQ. (Leguminosae) contains eight sugar units and two monoterpenyl moieties in the molecule. It has been proved that at least one of the monoterpenyl groups is attached to the C-2 hydroxyl of the terminal L-rhamnosyl group in the C-28 oligoside portion of GS-C on the basis of upper-field shifting of the ¹³C nuclear magnetic resonance signal of the anomeric carbon, which was refined by means of a partially relaxed Fourier transform (PRFT) experiment.