Four new triterpenoidal saponins acylated with one monoterpenic acid from Gleditsia sinensis

Four new oleanane-type triterpenoidal glycosides, named gleditsiosides A-D (1-4), were isolated from the anomalous fruits of Gleditsia sinensis. Using modern NMR techniques, including DQF-COSY, HETCOR, HOHAHA, HMBC, and ROESY experiments and RIS analysis as well as chemical methods, their structures were determined as 3-O-beta-D-xylopyranosyl-( 1-->2)-alpha-L-arabinopyrano syl-(1-->6)-beta-D-glucopyranosyl oleanolic acid 28-O-beta-D-xylopyranosyl- (1-->3)-beta-D-xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-[(6S,2 E)-6-hydroxy-2,6-dimethyl-2,7-octadienoyl-(1-->6)]-beta-D-glucopyranosyl es ter (1); 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)- beta-D-glucopyranosyl oleanolic acid 28-O-beta-D-xylopyranosyl-(1-3)-beta-D -xylopyranosyl-(1-->4)-alpha-L-rhamnopyranosyl-(1-->2)-[(2E)-2-hydroxylmeth yl-6-hydroxy-6-methyl-2,7-octadienoyl-(1-->6)]-beta-D-glucopyranosyl ester (2); 3-O-beta-D-xylopyranosyl-(1-->2)-alpha-L-arabinopyranosyl-(1-->6)-beta -D-glucopyranosyl echinocystic acid 28-O-beta-D-xylopyranosyl-(1-->3)-beta- D-xylopyranosyl-(1-->4)-[beta-D-galactopyranosyl-(1-->2)]-alpha-L-rhamnopyr anosyl-(1-->2)-[(2E)-2-hydroxylmethyl-6-hydroxy-6-methyl-2,7-octadienoyl-(1 -->6)]-beta-D-glucopyranosyl ester (3); and 3-O-beta-D-xylopyranosyl-(1-->2 )-alpha-L-arabinopyranosyl-(1-->6)-beta-D-glucopyranosyl echinocystic acid 28-O-beta-D-xylopyranosyl-(1-->3)-beta-D-xylopyranosyl-(1-->4)-[beta-D-gala ctopyranosyl-( 1-->2)]-alpha-L-rhamnopyranosyl-(1-->2)-[(6S,2E)-6-hydroxy-2 ,6-dimethyl-2,7-octadienoyl-(1-->6)]-beta-D-glucopyranosyl ester (4).