PTP1B inhibitors from Ardisia japonica.

In bioassay-directed isolation from the whole plant of Ardisia japonica, sixteen known compounds: chrysophanol (1), physcion (2), oleanolic acid (3), euscaphic acid (4), tormentic acid (5), quercetin (6), quercitrin (7), myricitrin (8), kaempferol 3-O-alpha-L-rhamnopyranoside (9), cyclamiretin A 3-O-alpha--rhamnopyranosyl(1-->4)-beta-D-glucopyranosyl(1-->2)-[beta-D-glucopyranosyl(1-->4)]-alpha-L-arabinopyranoside (10), (7E)-9-hydroxymegastigma-4, 7-dien-3-on-9-O-beta-D-glucopyranoside (11), bergenin (12), norbergenin (13), rutin (14), kaempferol 3,7-O-alpha-L-dirhamnopyranoside (15), (-)-epigallacatechin 3-O-gallate (16) were obtained. Compounds 1-5, 9, 11 and 14-16 have not been reported previously from this plant. Among these isolates, 2, 3, 6 and 12 showed moderate bioactivity against PTP1B in vitro with IC50 values of 121.50, 23.90, 28.12 and 157 microM, respectively.