title: [Studies on flavonoids and their antioxidant activities of Artemisia annua].
abstract: OBJECTIVE
  To study the flavonoids and their antioxidant activities of Artemisia annua.
  
  
  METHODS
  Isolation and purification were carried out by silica gel and Sephadex LH-20 column chromatographies. Compounds were identified by physicochemical properties and spectral analysis, then their antioxidant activities were evaluated by ORAC assay.
  
  
  RESULTS
  Five flavonoids were isolated from the plant. Their structures were identified as 5-hydroxy-3,7,4'-trimethoxyflavone(1), 5-hydroxy-6,7,3',4'-tetramethoxyflavonol(2), blumeatin(3), 5, 4'-dihydroxy-3,7,3'-trimethoxyflavone(4) and quercetin(5), respectively. Compounds 1-5 could slow up the attenuation rate of the fluorescence induced by AAPH.
  
  
  CONCLUSIONS
  Compounds 1-3 are isolated from the plant for the first time. Compounds 1-5 all possess the potential antioxidant activities.
authors.affiliation: Department of Phytochemistry, China Pharmaceutical University, Nanjing 210038, China. 200203684@sina.com.cn
authors.forename: Guo-en
authors.initials: GE
authors.lastname: Yang
authors.forename: Li
authors.initials: L
authors.lastname: Bao
authors.forename: Xiao-qi
authors.initials: XQ
authors.lastname: Zhang
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Qian
authors.initials: Q
authors.lastname: Li
authors.forename: Wei-ku
authors.initials: WK
authors.lastname: Zhang
authors.forename: Wen-cai
authors.initials: WC
authors.lastname: Ye
mesh_terms: D000975:Antioxidants / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D031172:Artemisia annua / Q000737:chemistry*; D047309:Flavones / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology; D005419:Flavonoids / Q000737:chemistry / Q000302:isolation & purification* / Q000494:pharmacology*; D015394:Molecular Structure; D010946:Plants, Medicinal / Q000737:chemistry*; D011794:Quercetin / Q000031:analogs & derivatives / Q000737:chemistry / Q000302:isolation & purification / Q000494:pharmacology
chemical_list: C501183:3',5,6-trihydroxy-3,4',7-trimethoxyflavone; D000975:Antioxidants; D047309:Flavones; D005419:Flavonoids; C084491:blumeatin; C008751:pachypodol; D011794:Quercetin