Abstract
Alkaloids and sesquiterpene lactone fractions have been isolated from different Iraqi plants which belong to different families. The antimicrobial activity of these fractions has been studied. Anti-Gram (+) bacterial activity have been detected, and only Ammi visnaga and Prosopis farcta exhibited activity against Candida species. In general no significant differences were observed between the activity of sesquiterpene lactones and alkaloids in the studied plants.