Two triterpene saponins from Achyranthes bidentata

Bidentatoside II (1) and chikusetsusaponin V methyl ester (2) are two furth er triterpene saponins isolated from the roots of Achyranthes bidentata. Ch emical and homo and heteronuclear two-dimensional (2D) NMR techniques have led to the structural elucidation of 1 which is a new seco-glycoside of ole anolic acid and the full H-1- and C-13-NMR assignments of 2. These compound s did not show any potentiation of the in vitro cytotoxicity of cisplatin i n the HT 29 human colon cancer cell line.