Flavones and sesquiterpene lactones from Achillea atrata subsp multifida: Antimicrobial activity

Four flavones (1-4) and nine sesquiterpene lactones (5-13), one of them (5) a new compound, were isolated from the aerial parts of Achillea atrata L. subsp. multifida. Although the crude extract demonstrated in vitro inhibito ry activity against Candida albicans and Bacillus subtilis, all isolated fl avones were active against B. subtilis. Flavones 1, 2, and 3 were also acti ve against C. albicans, while 1 and 3 exhibited activity against E. coli, a s well. None of the tested lactones (7, 9, 12, and 13) showed any antimicro bial activity.