Antioxidant activity-guided isolation of flavonoids from Silene gallica aerial parts

A bio-guided fractionation of the 80% aqueous ethanolic extract aerial parts Silene gallica L. (Caryophyllaceae), growing in North-Eastern Algeria, was performed to evaluate its antioxidant activity using DPPH, hydroxyl radical scavenging and CUPRAC assays. Successive chromatographic separations most n-BuOH soluble fraction yielded four acylated flavone C-glycosides, vitexin 2''-O-?-d-(4''',6'''-di-acetyl)-glucopyranoside (1), orientin-2''-O-?-d-(4''',6'''-di-acetyl)-glucopyranoside (2), orientin-2''-O-?-d-(6'''-feruloyl)-glucopyranoside (3), orientin-2''-O-?-d-(6'''-sinapoyl)-glucopyranoside (4), as well six known compounds including flavonoids (5-8), a phenylpropanoid glycerolglucoside (regaloside A) (9), phytoecdysteroide (20-hydroxyecdysone) (10). Their structures were established by UV, 1D, 2D NMR, HR-ESI-MS spectral data, addition comparison with literature data. The crude extracts, fractions 1-8 evaluated. Two orientin glycosides (3 4) displayed strongest activity.