Cytotoxic Triterpenoid Saponins from Ardisia gigantifolia

Three new triterpenoid saponins, 1-3, together with two known saponins, 4 and 5, were isolated from the rhizome of Ardisia gigantifolia. Their structures were elucidated by 1D and 2D NMR spectroscopic studies. Saponins 1, 2, 4, and 5 exhibited significant cytotoxicity against four human cancer cell lines, namely, Hela human cervical carcinoma cells, EJ human bladder tumor cells, HepG-2 human hepatoma cells, and BCG human gastric carcinoma cells with IC50 values in the range of 1.9-4.8 mu M.