title: Comparative study on the antioxidant activities of extracts of Coreopsis tinctoria flowering tops from Kunlun Mountains, Xinjiang, north-western China.
abstract: Coreopsis tinctoria flowering tops (CTFs) from the Kunlun Mountains in Xinjing (north-western China) have been used for tea production for about a century. This study aims to assess the antioxidant activities and total phenolic, flavonoid and proanthocyanidin contents of various solvent extracts of CTF. CTF was extracted using n-hexane, chloroform, ethyl acetate, n-butanol, 75% aqueous ethanol (AEE) and water. The antioxidant activities of the CTF extracts were investigated through DPPH, ABTS, *OH, *O2(-), total antioxidant capacity and reducing power assays. The results showed that n-butanol extract showed the highest contents of total phenols and flavonoids, with DPPH, ABTS and *OH radical-scavenging activities with IC50 values of 134, 90.72 and 13.8 μg mL(-1), respectively. The AEE demonstrated the strongest DPPH and ABTS radical-scavenging activities, with IC50 values of 103 and 75.16 μg mL(-1), respectively. Given its high antioxidant effect, CTF is a good source of natural antioxidants or functional food materials.
authors.affiliation: a College of Pharmacy, Shihezi University , Shihezi , 832000 Xinjiang , P.R. China.|b Ministry of Education Key Laboratory of Xinjiang Endemic Phytomedicine Resources, Shihezi University , Shihezi , 832000 Xinjiang , P.R. China.
authors.forename: Xincheng
authors.initials: X
authors.lastname: Yao
authors.affiliation: c School of Chemistry and Chemical Engineering, Shihezi University , Shihezi , 832002 Xinjiang , P.R. China.
authors.forename: Chengzhi
authors.initials: C
authors.lastname: Gu
authors.affiliation: a College of Pharmacy, Shihezi University , Shihezi , 832000 Xinjiang , P.R. China.|b Ministry of Education Key Laboratory of Xinjiang Endemic Phytomedicine Resources, Shihezi University , Shihezi , 832000 Xinjiang , P.R. China.
authors.forename: Liping
authors.initials: L
authors.lastname: Tian
authors.affiliation: a College of Pharmacy, Shihezi University , Shihezi , 832000 Xinjiang , P.R. China.|b Ministry of Education Key Laboratory of Xinjiang Endemic Phytomedicine Resources, Shihezi University , Shihezi , 832000 Xinjiang , P.R. China.
authors.forename: Xinbing
authors.initials: X
authors.lastname: Wang
authors.affiliation: a College of Pharmacy, Shihezi University , Shihezi , 832000 Xinjiang , P.R. China.|b Ministry of Education Key Laboratory of Xinjiang Endemic Phytomedicine Resources, Shihezi University , Shihezi , 832000 Xinjiang , P.R. China.
authors.forename: Hui
authors.initials: H
authors.lastname: Tang
mesh_terms: D000975:Antioxidants / Q000302:isolation & purification / Q000494:pharmacology*; D001713:Biphenyl Compounds / Q000737:chemistry; D002681:China; D031945:Coreopsis / Q000737:chemistry*; D005419:Flavonoids / Q000032:analysis; D035263:Flowering Tops / Q000737:chemistry; D016166:Free Radical Scavengers / Q000737:chemistry / Q000494:pharmacology; D017665:Hydroxyl Radical; D010636:Phenols / Q000032:analysis; D010851:Picrates / Q000737:chemistry; D010936:Plant Extracts / Q000494:pharmacology*; D044945:Proanthocyanidins / Q000032:analysis; D012997:Solvents
chemical_list: D000975:Antioxidants; D001713:Biphenyl Compounds; D005419:Flavonoids; D016166:Free Radical Scavengers; D010636:Phenols; D010851:Picrates; D010936:Plant Extracts; D044945:Proanthocyanidins; D012997:Solvents; C013221:proanthocyanidin; D017665:Hydroxyl Radical; C004931:1,1-diphenyl-2-picrylhydrazyl
keywords: Coreopsis tinctoria Nutt; antioxidant activity; radical scavenging activity