title: Phenolic compounds in field horsetail (Equisetum arvense L.) as natural antioxidants.
abstract: In this paper, the study of antioxidant activity and phenolic composition of three different extracts (EtOAc, n-BuOH and H(2)O) of field horsetail (Equisetum arvense L.) is presented. The antioxidant activity has been evaluated measuring the total reducing power (expressed by Ascorbate Equivalent Antioxidant Capacity - AEAC), inhibition of lipid peroxidation, and free radical scavenging capacity (RSC) towards 2,2-diphenyl-1-picrylhydrazyl (DPPH radical) and nitric oxide (NO), respectively. In addition, the total flavonoid content (TFC) and phenolic constituents of each extract have been determined. The results obtained show that the highest RSC regarding both DPPH and NO radicals is expressed by EtOAc extract (EC(50)=2.37 microg/mL and EC(50)=90.07 microg/mL, respectively), and the lowest by H(2)O extract (EC(50)=37.2 microg/mL and EC(50)>333.33 microg/mL, respectively). n-BuOH extract showed the highest total reducing power (AEAC=13.40 microg/mL). Differences in the phenolic composition of examined extracts are found comparing the HPLC chemical profiles. Although, isoquercitrin is the main flavonoid in both EtOAc and n-BuOH extracts, a considerable amount of di-E-caffeoyl-meso-tartaric acid was presented in the n-BuOH extract. In H(2)O extract high content of phenolic acids and low percentage of flavonoids were detected.
authors: Department of Chemistry, Faculty of Sciences, Trg D. Obradovica 3, University of Novi Sad, 21000 Novi Sad, Serbia. mimica@ih.ns.ac.yu
authors: Neda
authors: N
authors: Mimica-Dukic
authors: Natasa
authors: N
authors: Simin
authors: Jelena
authors: J
authors: Cvejic
authors: Emilija
authors: E
authors: Jovin
authors: Dejan
authors: D
authors: Orcic
authors: Biljana
authors: B
authors: Bozin
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D020829:Equisetum / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry; D008081:Liposomes / Q000737:chemistry; D009569:Nitric Oxide / Q000737:chemistry; D010636:Phenols / Q000737:chemistry*; D010936:Plant Extracts / Q000737:chemistry; D013056:Spectrophotometry, Ultraviolet
chemical_list: D000975:Antioxidants; D005419:Flavonoids; D008081:Liposomes; D010636:Phenols; D010936:Plant Extracts; D009569:Nitric Oxide