Four bisabolane sesquiterpenoids, α-curcumene, ar-turmerone, β-atlantone and xanthorrhizol, were isolated as major antitumor constituents (against Sarcoma 180 ascites in mice) from the rhizomes of Curcuma xanthorrhiza. Their structures were deduced from spectroscopic evidence. The antitumor effectivenes was rated (+ + +) for α-curcumene, (+ +) for ar-turmerone and (+ +) for xanthorrhizol at 50 mg/kg in the total packed cell volume method.
