The flavonoid glycosides: patuletin 7-O-b-glucopyranoside 3, hispidulin 7-O-b-glucopyranoside 2 together with hispidulin 1, were isolated from the n-butanol soluble part of the aqueous-MeOH extract of the flowering aerial parts of C. acaulis L. (Asteraceae), an endemic species of Algeria and Tunisia. The structures were established by chemical and spectral analysis, mainly HR-ESIMS, UV and NMR experiments (COSY, NOESY, HSQC and HMBC). Patuletin 7-O-b-glucopyranoside showed a high antioxidant effect, especially scavenging of DPPH (IC50 = 4.83 μg/ml) anions and inhibition of lipid peroxidation (51.93%.). Those various antioxidant activities were compared to vitamin C (standard antioxidant).
