Triterpene saponins from Randia formosa

Seven new triterpenoid saponins, randiasaponins I (1), II (2), III (3), IV (4), V (5), VI (6) and VII (7) as well as two known ones, ilexoside XXVII ( 8) and ilexoside XXXVII (9), were isolated from the methanolic extract of t he leaves of Randia formosa. The structures of the new saponins were establ ished as 3-O-alpha-L-arabinopyranosyl-3 beta,19 alpha,23-trihydroxyursa-12, 20(30)-dien-28-oic acid 28-beta-D-glucopyranosyl ester (I), 3-O-beta-D-gluc opyranosyl-(1 --> 3)-alpha-L-arabinopyranosyl rotundic acid (2), 3-O-beta-D -glucopyranosyl-(1 --> 3)-alpha-L-arabinopyranosyl pomolic acid 28-beta-D-g lucopyranosyl eater (3), 3-O-51-L-rhamnopyranosyl-(1 --> 2)-alpha-L-arabino pyranosyl pomolic acid 28-beta-D-glucopyranosyl ester (4), 3-O-a-L-rhamnopy ranosyl-(l --> 2)-alpha-L-arabinopyranosyl siaresinolic acid 28-beta-D-gluc opyranosyl ester (5), 3-O-alpha-L-arabinopyranosyl ilexosapogenin A 28-beta -D-glucopyranosyl ester (6), and 3-O-beta-D-glucopyranosyl ilexosapogenin A 28-beta-D-glucopyranosyl ester (7), based on spectral and chemical evidenc e. Besides the saponins, two common flavonoids kaempferol 3-O-rutinoside an d rutin were also isolated. (C) 2000 Published by Elsevier Science Ltd. All rights reserved.