Triterpenes from the Aerial Parts of <i>Cimicifuga yunnanensis</i> and Their Antiproliferative Effects on p53^N236S Mouse Embryonic Fibroblasts

Abstract

Nine new triterpene derivatives, yunnanterpenes A–F (1–6), 15,16-seco-cimiterpenes A and B (7, 8), and cimilactone C (9), and 15 known analogues (10–24) were isolated from the aerial parts of Cimicifuga yunnanensis. The new structures were established using a combination of MS, NMR, and single-crystal X-ray diffraction techniques. WT MEFs (wild-type mouse embryonic fibroblasts) and tumorigenic cell lines p53–/–+H-RasV12 and p53–/–+p53N236S+H-RasV12 were used for evaluating active structures, targeting p53N236S (corresponding to p53N239S in humans) mutation. Compound 5 showed nonselective activities against these cell lines, with IC50 values of 5.8, 8.6, and 6.0 μM, respectively. Compound 4 exhibited greater selectivity against the p53–/–+p53N236S+H-RasV12 cells (IC50 5.5 μM) than against the WT MEFs cells (IC50 14.3 μM).