AbstractTwo new sesquiterpenes petrovin A (1) and petrovin B (2) have been isolated from Chinese herb Saussurea petro-vii and their structures established by spectroscopic methods. Compounds 1 and 2 showed significant antibacterial and antitumour activity.KeywordssesquiterpenesantibacterialantitumorReferences1. Ma Y.-C. , Fu H.-C. , and Chen S. , (eds). Flora Intramongolica, 2nd Ed., Vol. 6, Intramongolia People's Press, Huhhot, 1982, 244.2. Sy L.K. , and Brown G. D. , Phytochemistry, 1998, 48, 1207.3. Li S.L. , Ding J. G. , Jiang B. , and Na B. B. , Phytochemistry, 1998, 49, 2035.4. Ahmed A.A. , El-Seedi H. R. , and Mahmoud A. A. , Phytochemistry, 1998, 49, 2421.5. Price P. , and Mcmillan T. J. , Cancer Res., 1990, 50, 1392.6. Xu S.Y. , and Bian Q. L. , Pharmacology Experimental Methods, People's Health Press, Beijing, 1982, 1340.