Bioassay-guided fractionation of the chloroform extract of Centaurea jacea L. afforded the isolation of cirsiliol, apigenin, hispidulin, eupatorin, isokaempferide, axillarin, centaureidin, 6-methoxykaempferol 3-methyl ether, trachelogenin, cnicin, 4'-acetylcnicin and three aliphatic glucose