OLEANENE-TYPE TRITERPENE GLYCOSIDES FROM PUERARIAE RADIX .2. ISOLATION OF SAPONINS AND THE APPLICATION OF TANDEM MASS-SPECTROMETRY TO THEIRSTRUCTURE DETERMINATION

A continuing study of the ingredients of Puerariae Radix, the roots of Pueraria lobata (WILLD.) OHWI, which is one of the most important cru de drugs, has resulted in the first isolation of four new oleanene-typ e triterpene glycosides, named kudzusaponins SA(1), SA(2), SA(3) and C -1 (1-4). Their structures were determined to be galactopyranosyl-(1-- >2)-beta-D-glucuronopyranosyl soyasapogenol A (1), galactopyranosyl-(1 -->2)-beta-D-glucuronopyranosyl soyasapogenol A 22-O-alpha-L-arabinopy ranoside (2), -rhamopyranosyl-(1-->2)-beta-D-galactopyranosyl-(1 -->2) -beta-D-glucuronopyranosyl soyasapogenol A 22-O-alpha-L-arabinopyranos ide (3) and 3-O-alpha-L-rhamopyranosyl-(1 galactopyranosyl-(1-->2)-bet a-D-glucuronopyranosyl kudzusapogenol C 21-O-beta-D-glucopyranoside (4 ), respectively. The usefulness of tandem mass spectrometry in the str uctural determination of oleanene-type triterpene bisdesmosides is als o discussed.