title: Antioxidant activities of extracts and flavonoid compounds from Oxytropis falcate Bunge.
abstract: The antioxidant properties of the various extracts and flavonoids prepared from Oxytropis falcate Bunge were investigated by 1,1-diphenyl-2-picryldydrazyl (DPPH) radical-scavenging assay. In the chloroform, ethyl acetate and n-butanol extracts, the ethyl acetate extract exhibited the highest antioxidant activity (IC(50) = 2.05 mg mL(-1)). Furthermore, rhamnocitrin, kaempferol, rhamnetin, 2',4'-dihydroxychalcone and 2',4', beta-trihydroxy-dihydrochalcone were purified from chloroform and ethyl acetate extracts. The radical-scavenging activities of the five compounds were also measured and the results showed that kaempferol (IC(50) = 0.11 mg mL(-1)), rhamnetin (IC(50) = 0.14 mg mL(-1)) and rhamnocitrin (IC(50) = 0.15 mg mL(-1)) exhibited considerable antioxidant activities, but the antioxidant activities of the two dihydrochalcones were very weak. Although these flavonoids are known, this is the first report of antioxidant activity in this plant.
authors.affiliation: Key Laboratory for Natural Medicine of Gansu Province, Lanzhou Institute of Chemical Physics, Chinese Academy of Sciences, Lanzhou, China. huajiang931@sina.com
authors.forename: H
authors.initials: H
authors.lastname: Jiang
authors.forename: W Q
authors.initials: WQ
authors.lastname: Zhan
authors.forename: X
authors.initials: X
authors.lastname: Liu
authors.forename: S X
authors.initials: SX
authors.lastname: Jiang
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D001713:Biphenyl Compounds; D050150:Chalones / Q000187:drug effects; D004365:Drugs, Chinese Herbal / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D033021:Oxytropis / Q000737:chemistry*; D010851:Picrates / Q000494:pharmacology; D010946:Plants, Medicinal / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D050150:Chalones; D004365:Drugs, Chinese Herbal; D005419:Flavonoids; D016166:Free Radical Scavengers; D010851:Picrates; C004931:1,1-diphenyl-2-picrylhydrazyl