Three spirostanol saponins and a flavane-O-glucoside from the fresh rhizomes of Tupistra chinensis.

Four new compounds, including three new spirostanol saponins [tupistroside G-I (1-3)] and a new flavane-O-glucoside [tupichiside A (4)], together with ten known compounds, were isolated from the fresh rhizomes of Tupistra chinensis. The structures of the new compounds were elucidated by spectroscopic analysis and chemical evidence. All compounds were tested in vitro for their cytotoxic activities against the Human LoVo and BGC-823 cell lines, and six of them were found to possess potent cytotoxicity. Compounds 2, 8 and 9 showed significant cytotoxicity against the tested tumor cell lines with IC50 values ranging from 0.2 to 0.9μM.