Abstract

Coix lacryma-jobi L. is a traditional Chinese medicine, and has been investigated to treat inflammatory diseases and rheumatism. An antitumor active compound was isolated from the stems and leaves of Coix lacryma-jobi L. The molecular weight of this compound was 410 using mass spectrum analysis . The structural identification of the purified compound was determined using ultraviolet spectroscopy , Fourier transform infrared spectroscopy and nuclear magnetic resonance spectra, which showed that the compound was (20R)-22E-24-ethylcholesta-4,22-dien-3-one. HeLa, HepG2 and SGC-7901 cells for survival had a minimum IC 50 values with this compound of 23.8, 67.6 and 25.5 μg/mL, respectively. The compound had pro-apoptotic effects on three types of tumor cells, and had an inhibitory effect on DNA topoisomerase I. The effect was concentration dependent, but the compound did not cleave the DNA. The structure-activity relationship and action mechanism were explored, to provide a specific basis for the synthesis and development of antitumor drugs.