A Cytotoxic Natural Product from Patrinia villosa Juss

Background and Purpose: Patrinia villosa Juss is an important Chinese herbal medicine widely used for thousands of years, but few reports on the ingredients of the herb have been presented. In this study, we aim to isolate the bioactive compound from the plant. Material and Methods: The air-dried leaves of P. villosa (15kg) were extracted three times with 70% EtOH under reflux. The condensed extract was suspended in H2O and partitioned with light petroleum, dichloromethane and n-BuOH. The dichloromethane portion was then subjected to normal-phase silica gel column chromatography, ODS silica gel column chromatography and semi-preparative HPLC to yield compound 1. Cytotoxicities of 1 were assayed on HepG2, A549 and A2780 cell lines. The mechanism of apoptosis and cell cycle on A549 was confirmed subsequently. Results: A new impecylone (Impecylone A) was isolated from the leaves of Patrinia villosa Juss, and its structures were established using 1D, 2D-NMR spectra and HR-ESI-MS. Impecylone A could selectivity inhibit HepG2 and A549 cell lines. The compound could induce apoptosis of A549 and arrest the cell cycle at G2/M phase in a dose-dependent manner. Conclusion: Impecylone A is a novel compound from Patrinia villosa Juss and could be a potential antitumor agent especially in the cell lines of A549.