Bidentatoside I (1) is a new triterpene saponin bearing an unusual dioxopro
pionic acid unit, isolated from the roots of Achyranthes bidentata. Structu
ral elucidation was performed mainly by chemical and homo- and heteronuclea
r 2D NMR techniques. This compound did not show any potentiation of the in
vitro cytotoxicity of cisplatin in the HT 29 human colon cancer cell line.