Centaurea species: Potentially source of sesquiterpene lacton cnicin

Sesquiterpene lactones constitute one of the biggest group of natural products. Up to now, the structures of ca. 5.000 sesquiterpene lactones of natural origin plus hundreds of synthetic ones have been reported. The sesquiterpene lactone cnicin have most potentially importance. Chemotaxonomic importance, together with various biological activities (antitumor, allergenic, phytotoxic, antimicrobial, insecticidal, etc) are the major reasons for the continuing interests in this compound. Cnicin was for the first time reported from Cnicus benedictus (0.2-0.7%). In the genus Centaurea the most of species contain sesquiterpene lactone cnicin i.e. C. diffusa (0.81%), C. squarrosa (0.8%), C. affinis (0.46%), C. stoebe (0.45%) C. derventana (0.2%), C. nicaeensis (0.19%), C. brugerrina (0.16%), C. calcitrapa L. (0.06%). The fact that amount of sesquiterpene lactone cnicine in Centaurea species is most higer than in Cnicus benedictus, suggest conclusion that the species from this genus are most potentially source of sesquiterpene lactone cnicine possessing various biological activities.