Triterpenoid saponins of Alternanthera philoxeroides (Mart.) Griseb

In order to find the anti-virus constituents of Alternanthera philoxeroides (Mart.) Griseb, the investigation was carried out.  The paper reported the five triterpenoid saponins isolated from n-BuOH fraction: 3-O-β-D-glucopyranosyl (1→3)-O-β-D-glucopyranosyl-oleanolic acid-28-O-β-D-glucuronopyranoside (1), oleanolic acid-3-O-β-D-glucuronopyranoside (calenduloside E, 2), oleanolic acid-3-O-β-D-glucopyranosyl-28-O-β-D-glucopyranosyl ester (chikusetsusaponin-Ⅳa, 3), 3-O-(6'-O-butyl-β-D-glucuronopyranosyl)-oleanolic acid-28-O-β-D-glucopyranosyl ester (4) and hederagenin-3-O-β-D-glucuronopyranoside (HN-sapoins K, 5).  Saponin 1 is a new compound, saponins 4 and 5 were isolated from the plant for the first time.