title: [Antioxidant activity constituents from root of Rubus crataegifolius].
abstract: OBJECTIVE
  To study the antioxidant constituents from the root of Rubus crataegifolius.
  
  
  METHODS
  The constituents isolation and purification from the root of R. crataegifolius was carried by reported column chromatography including silica gel, toyopearl, and their structures were elucidated on the basis of spectral compounds. DPPH method was used to evaluate the free radical scavenging activity of the isolated compounds.
  
  
  RESULTS
  Nine compounds were isolated from the root of R. crataegifolius, and their structures were identified as follow: euscaphic acid (1), kaempferol-3-O-beta-D-galactopyranoside (2), tormentic acid (3), 2alpha, 19alpha, 24-trihydroxyurs-12-ene-3-oxo-28-acid (4) , 2alpha-hydroxy-oleanolic acid (5), ursolic acid (6), daucosterol (7), beta-sitosterol (8) and polydatin (9). By experiment of antioxidant activity, the result showed compounds 2 and 9 revealed DPPH free radical scavenging rates were 95.60% and 75.23% at the concentration of 50 mg x L(-1).
  
  
  CONCLUSIONS
  Compounds 1-8 were isolated from this plant for the first time, and compounds 2 and 9 showed the significant antioxidant activity.
authors.affiliation: Jilin Modern Medical and Biopharmaceutical Base Office, Changchun 130041, China. jlszyb@163.com
authors.forename: Zhong-Bao
authors.initials: ZB
authors.lastname: Wei
authors.forename: Jia-Ming
authors.initials: JM
authors.lastname: Sun
authors.forename: Peng-Fei
authors.initials: PF
authors.lastname: Li
authors.forename: Shuai
authors.initials: S
authors.lastname: Wang
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Zhe
authors.initials: Z
authors.lastname: Lin
mesh_terms: D000975:Antioxidants / Q000737:chemistry* / Q000302:isolation & purification; D004365:Drugs, Chinese Herbal / Q000737:chemistry* / Q000302:isolation & purification; D018517:Plant Roots / Q000737:chemistry; D027824:Rosaceae / Q000737:chemistry*
chemical_list: D000975:Antioxidants; D004365:Drugs, Chinese Herbal