Terpenoids from Artemisia annua and constituents of its essential oil (original) (raw)

The hexane extract of the aerial part of Artemisia annua yielded three new cadinanes along with several known compounds of which five have been isolated for the first time from this plant. The essential oil of its aerial part afforded artemisia ketone, cineole and camphor as major components together with several minor components. Structures were elucidated by spectroscopic and chemical transformation methods. INTRODUmION We have recently reported the crystal structure of artemisinic acid (1) [l] and the structure of novel bisnorcadinanes (2,3) [2] from the hexane extract of the aerial part of Artemisia annua. We now describe the identification of other compounds from this plant together with the detailed chemical investigation of the essential oil. CIMAP approval number 93-675. *Author to whom correspondence should be addressed. RESULTS AND DISCUSSION Column chromatographic separations of the hexane extract of the aerial part of A. annua yielded l-6, aamyrenone, a-amyrin, fl-amyrin, taraxasterone, oleanolic acid, stigmasterol, sitosterol, and baurenol. a-Amyrenone, /3-amyrin, baurenol, taraxasterone and oleanolic acid are reported for the first time from A. annua. Compounds 4-6 were new cadinanes and their structure elucidation was carried out mainly by spectroscopic methods. The IR spectrum of 4 showed bands at 3500 and 17OOcm-' for hydroxyl and carbonyl groups, respect-4, R=COCHM% 5 R'=H