Sesquiterpene lactones from plant species Centaurea solstitialis L.

The identification of nine known guaianolides, i.e., solstitialin A, its 13-acetate, linichlorin B, cynaropicrin, centaurepensin (chlorohyssopifolin A), 17-epi-centaurepensin, 19-desoxychlorojanerin, 11ß,13-dihydrodesacylcynaropicrin and 8-desacylcentaurepensin-8-O-(4-hydroxy)tiglate in the aerial parts of Centaurea solstitialis is reported. The last four lactones were isolated for the first time from this species. Other compounds detected in this extract, not found before in C. solstitialis, were syringaresinol (lirioresinol B) and arctigenin (the known lignans)