Achyranbidens A-C: three new compounds from Achyranthes bidentata Blume

Phytochemical study on the roots of Achyranthes bidentata Blume led to the isolation of sixteen compounds including three new ones (1-3). Their chemical structures were determined as oleanolic acid 28-O-β-D-glucopyranoside-3-O-[β-D-glucopyranosyl-(1→3)-β-D-galactopyranoside) (1), methyl (8Z,11Z)-5,6,7-trihydroxytetradeca-8,11-dienoate (2), methyl (6E,11Z)-5,8,9-trihydroxytetradeca-6,11-dienoate (3), fulgidic acid (4), (9E,11E)-13-oxooctadeca-9,11-dienoic acid (5), (9Z,11E,15Z)-13-hydroxyoctadeca-9,11,15-trienoic acid (6), oleanolic acid 28-O-β-D-glucopyranoside-3-O-α-L-rhamnopyranosyl-(1→4)-β-D-glucuronopyranoside (7), oleanolic acid 28-O-β-D-glucopyranoside-3-O-β-D-glucopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→3)]-β-D-glucuronopyranoside (8), oleanolic acid 3-O-β-D-glucopyranosyl-(1→2)-[α-L-rhamnopyranosyl-(1→3)]-β-D-glucuronopyranoside (9), oleanolic acid 3-O-α-L-rhamnopyranosyl-(1→3)-β-D-glucuronopyranoside (10), blumenol C glucoside (11), citroside A (12), 6S,9S-roseoside (13), ginsenoside Rg1 (14), 20-hydroxyecdysone (15), and benzyl α-L-rhamnopyranosyl-(1→6)]-β-D-glucopyranoside (16) by spectroscopic analysis. Compounds 1, 7 and 11-16 inhibited NO production in LPS-activated RAW264.7 cells with IC₅₀ values in the range from 28.03 to 54.23 µM (positive control, L-NMMA: IC₅₀ = 35.52 µM). Compounds 14 and 15 showed anti α-glucosidase activity with IC₅₀ values of 176.24 and 156.92 µM, respectively, compared with the positive control, acarbose, IC₅₀ = 160.99 μM.