title: [Tyrosinase inhibition of Potentilla bifurca].
abstract: OBJECTIVE
  To identify the tyrosinase inhibitory constituent quickly from Potentilla bifurca.
  
  
  METHODS
  The active constituent was found through fraction collecting and tyrosinase inhibitory activity by bioassay-linked HPLC method.
  
  
  RESULTS
  The methanol extracts and BuOH fraction of Potentilla bifurca showed strong tyrosinase inhibitory activities. From BuOH fraction of Potentilla bifurca, the tyrosinase inhibitory constituent was isolated and identified as flavonoid, quercetin-4'-O-beta-D-glucoside. It express stronger tyrosinase inhibition than the known tyrosinase inhibitor, kojic acid (IC50 = 0.28 mmol x L(-1)) with IC50 value of 0.001 9 mmol x L(-1).
  
  
  CONCLUSIONS
  Bioassay-linked HPLC fractionation method was provided for determination the active constituents quickly from herbal medicines.
authors.affiliation: Institute of Chinese Minority Traditional Medicine, Central University for Nationalities, Beijing 100081, China. xlpiao@cun.edu.cn
authors.forename: Xianglan
authors.initials: X
authors.lastname: Piao
authors.forename: Yanze
authors.initials: Y
authors.lastname: Tian
authors.forename: Xiaoyuan
authors.initials: X
authors.lastname: Mi
authors.forename: Jian
authors.initials: J
authors.lastname: Cui
mesh_terms: D004791:Enzyme Inhibitors / Q000737:chemistry* / Q000302:isolation & purification; D007700:Kinetics; D010455:Peptides / Q000737:chemistry* / Q000302:isolation & purification; D010936:Plant Extracts / Q000737:chemistry / Q000302:isolation & purification; D031987:Potentilla / Q000737:chemistry*
chemical_list: D004791:Enzyme Inhibitors; D010455:Peptides; D010936:Plant Extracts