[Constituents from Alternanthera philoxeroides and their antitumor activity].

To investigate antitumor constituents from n-butyl alcohol extract of Alternanthera philoxeroides.The constituents were isolated with silica gel, gel permeation chromatography, and purified by HPLC. Their structures were elucidated by spectroscopy and acid hydrolysis. The antitumor effects of extracts and isolated compounds were tested by MTH method in vitro.Seven compounds were isolated and elucidated as followings: oleanolic acid 3-O-beta-D-glucuronopyranoside (1), oleanolic acid 28-O-beta-D-glucopyranoside (2), oleanolic acid 3-O-beta-D-glucuronopyranoside-6'-O-methyl ester (3), chikusetsusaponin IV a methyl ester (4), hederagenin 3-O-beta-D-glucuronopyranoside-6'-O-methyl ester (5), 4,5-dihydroblumenol (6), 6S,7E,9R-6,9-di-hydroxymegastigma-4,7-dien-3-one-9-O-beta-D-glucopyranoside (7). Compound 1 showed significant inhibitory effect against Hela and L929 with inhibitive ratios 91.3% and 92.9% at 30 mg x L(-1), respectively.Compounds 4, 5 and 7 were isolated from this genus for the first time. Compound 1 showed significant inhibitory effect against Hela and L929 at 30 mg x L(-1).