Antitumor components isolated from the Chinese herbal medicine Coix lachryma-jobi.

The seeds of the gramineous plant Coix lachryma-jobi L. var. ma-yuen Stapf are a traditional Chinese medicine possessing antitumor activity. An acetone extract of the seeds was fractionated by the aqueous alkali method and by silica gel column chromatography in order to identify the antitumor components. Antitumor activity, as assayed by an in vivo growth inhibition test on a transplantable mouse tumor, was attributed to an acidic fraction. Infrared spectroscopy and gas-liquid chromatography showed that this acidic fraction was composed of four free fatty acids: palmitic, stearic, oleic, and linoleic acids.