Studies on the constituents of Cimicifuga foetida collected in Guizhou Province and their cytotoxic activities.

Two new triterpenoids and a chromone glycoside, namely, 24-epi-cimigenol-3-one (1), foetinoside (2), cimifugin-4'-O-[6″-feruloyl]-β-D-glucopyranoside (3), together with 18 known compounds, were isolated from the rhizomes of Cimicifuga foetida L. collected in Guizhou Province, China. All of the compounds were identified by spectroscopic methods, as well as chemical methods. In the in vitro cytotoxicity evaluation of these compounds against 5 human cancer cell lines, cimigenol (8) exerted the most potent cytotoxic activity against SMMC-7721 (7.87 µM) and A-549 (12.16 µM), while cimiacerin B (9) also showed obvious cytotoxicity against the A-549 cell line, with an IC(50) value of 16.77 µM.