Lignans and sesquiterpene lactones from Artemisia sieversiana and Inula racemosa.

The aerial parts of Artemisia sieversiana afforded, in addition to beta-sitosterol, stigmasterol and daucosterol, two novel lignans as well as one known and three new guaianolides. The roots of Inula racemosa gave beta-sitosterol, daucosterol and isoalantolactone. The structures were determined by a combination of spectral methods (IR, EIMS, 1H and 13C NMR, DEPT, COSY, NOESY and HETCOR). All isolates were subjected to antifungal tests. Isoalantolactone, a major sesquiterpene lactone of I. racemosa, was found to be active against the human pathogenic fungi. Aspergillus flavus, A. niger, Geotrichum candidum, Candida tropicalis and C. albicans at concentrations of 50, 50, 25, 25 and 25 micrograms/ml, respectively. The taxonomic significance of the characterized constituents is discussed briefly.