Studies on the Constituents of Amaranthus caudatus (Kiwicha) Seeds. Isolation and Characterization of Seven New Triterpene Saponins

Seven new triterpenoid saponins were isolated from the seeds of Amaranthus caudatus (Amaranthaceae). Their structures were elucidated on the basis of spectral and chemical data to be (1) 3-beta-O-alpha-L-rhamnopyranosyl-(1 leads to 2)-beta-D-glucopyranosyl-2beta,3beta-dihydroxyolean-12-en-28 -oic acid 28-O-beta-D-glucopyranosyl ester; (2) 3-beta-O-alpha-L-rhamnopyranosyl-(1 leads to)-6-O-methyl-beta-D-glucopyranosyl-2beta,3beta -dihydroxyolean-12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester; (3) 3-beta-O-alpha-L-rhamnopyranosyl-(1 leads to 2)-beta-D-glucopyranosyl-2beta,3beta-dihydroxy-2 3-oxoolean 12-en-28-oic acid 28-O-beta-D-glucopyranosyl ester; (4) 3-beta-O-alpha-L-rhamnopyranosyl-(1 leads 2)-beta-D-glucopyranosyl-2beta,3beta,6alpha- trihydroxy-23-oxoolean-12-en-28 oic acid 28-O-beta-D-glucopyranosyl ester; (5) 2beta,3beta-dihydroxy-30-norolean-12,20(29) diene-23,28-dioic acid 28-O-beta-D-glucopyranosyl ester; (6) 2beta,3beta-dihydroxy-30-norolean-12,20(29) diene-23,28-dioic acid 23,28-di-O-beta-D-glucopyranosyl ester; (7) 3-O-beta-D-glucopyranosyl-2beta,3beta-dihydroxy 3-O-norolean-12,20(29)-diene-23,28-dioic acid 23,28-di-O-beta-D-glucopyranosyl ester