Cytotoxic cycloartane triterpenes of the traditional Chinese medicine "shengma" (Cimicifuga dahurica).

Twelve new 9,19-cycloartane triterpenes (1-12), together with fourteen known compounds (13-26), were isolated from the roots of Cimicifuga dahurica. Their structures were determined by application of spectroscopic analyses and chemical methods. Biological evaluation of the compounds against human HL-60, SMMC-7721, A549, MCF-7, and SW-480 cell lines indicated that cimigenol-type glycosides (1-3, 19, and 20) showed broad-spectrum and moderate cytotoxicities, with IC50 values ranging from 4.2 to 14.5 µM. Meanwhile, cimigenol-type aglycones (6-8, 15, 16, and 18) exhibited broad-spectrum and week cytotoxicities, having IC50 values around 20 µM. In addition, the key points of the structure-activity relationships of aglycones with a cimigenol skeleton were discussed.