Study toward antioxidant activity of Clematis flammula extracts: Purification and identification of two flavonoids-glucoside and trisaccharide

Abstract The objective of this study was to investigate the antioxidant activity of Clematis flammula extracts and its main isolated compounds. The antioxidant tests were evaluated proceeding with DPPH-scavenging, reducing power (FRAP) and TAC-scavenging activity. The best antioxidant powers were given by leaf methanolic and hydro-alcoholic extracts with IC 50 of 120 and 90 μg/mL respectively. The flower extracts IC 50 were 410 and 190 μg/mL for the EtOAc and MeOH respectively. Fractionation of actives extracts led to the isolation of compounds identified to flavonoids glucosides 1 and 2 from MeOH and EtOAc flower residues and trisaccharide 3 from MeOH leaf extract. The present compounds showed antioxidant activities with IC 50 of 20, 80 μg/mL and 70 μg/mL respectively. Results proved that flavonoid 1 exhibited higher antioxidant effects than 2 . The antioxidant effects of main isolated molecules could be responsible of C. flammula antioxidant activity.