Isolation of the antiulcer compound in essential oil from the leaves of Cryptomeria japonica.

Essential oil from the leaves of Tateyamasugi (Cryptomeria japonica) exhibited strong inhibitory activity on ulceration induced by HCl/ethanol, HCl/aspirin, water-immersion stress and pylorus-ligation. We separated the antiulcer compounds from cedar essential oil by use of distillation and chromatography. As a result, terpinen-4-ol, a monoterpene, and elemol, a sesquiterpene, were isolated as active compounds. The antiulcer activity of the former was more potent than that of the latter. Terpinen-4-ol was a mixture of optical isomers and each possessed potent antiulcer activity. Secretion of gastric juice and output of acid and pepsin activity were lowered by terpinen-4-ol. These results suggest that terpinen-4-ol isolated from cedar essential oil could be a valuable antiulcer agent.