title: Studies of chemical constituents and their antioxidant activities from Astragalus mongholicus Bunge.
abstract: OBJECTIVE
  To evaluate the antioxidant activities of different chemical constituents from Astragalus mongholicus Bunge and their protection against xanthine (XA)/xanthine oxidase (XO)-induced toxicity in PC12 cells.
  
  
  METHODS
  The compounds of Astragalus mongholicus Bunge were isolated by chromatography and the structures were elucidated on the basis of spectral data interpretation. Their antioxidant activities were detected by 1, 1-diphenyl-2-picrylhydrazyl (DPPH) radical scavenging activities in a cell-free system. Meanwhile, the effects against XA/XO-induced toxicity were assessed using MTT assay in PC12 cells.
  
  
  RESULTS
  Ten principal constituents were isolated and identified as formononetin (I), ononin (II), calycosin (III), calycosin-7-O-beta-D-glucoside (IV), 9,10-dimethoxypterocarpan-3-O-beta-D-glucoside (V), adenosine (VI), pinitol (VII), daucosterol (VIII), beta-sitoster (IX) and saccharose (X) from Astragalus mongholicus Bunge. The compounds I, III, and IV scavenged DPPH free radicals in vitro. Formononetin and calycosin were found to inhibit XA/XO-induced cell injury significantly, with an estimated EC50 of 50 ng/mL.
  
  
  CONCLUSIONS
  Compound II, VI, and VII are first reported in this plant. Calycosin exhibits the most potent antioxidant activity both in the cell-free system and in the cell system.
authors.affiliation: Department of Environment and Biology, Dalian University of Technology, Dalian 116024, Liaoning, China.
authors.forename: De-Hong
authors.initials: DH
authors.lastname: Yu
authors.forename: Yong-Ming
authors.initials: YM
authors.lastname: Bao
authors.forename: Chao-Liang
authors.initials: CL
authors.lastname: Wei
authors.forename: Li-Jia
authors.initials: LJ
authors.lastname: An
mesh_terms: D000818:Animals; D027883:Astragalus Plant / Q000737:chemistry; D027885:Astragalus propinquus; D004365:Drugs, Chinese Herbal / Q000737:chemistry* / Q000494:pharmacology*; D016166:Free Radical Scavengers / Q000737:chemistry* / Q000494:pharmacology*; D005609:Free Radicals / Q000378:metabolism; D007529:Isoflavones / Q000737:chemistry / Q000494:pharmacology; D016716:PC12 Cells; D051381:Rats; D019820:Xanthine / Q000633:toxicity; D014969:Xanthine Oxidase / Q000633:toxicity
chemical_list: D004365:Drugs, Chinese Herbal; D016166:Free Radical Scavengers; D005609:Free Radicals; D007529:Isoflavones; D019820:Xanthine; C027492:Huang Qi; D014969:Xanthine Oxidase