title: [Analysis of main flavonoids contents of Scutellaria baicalensis].
abstract: OBJECTIVE
  To develop a HPLC-DAD method for simultaneous determination of six flavonoids in Scutellaria baicalensis, and study the effect of geographic sources, culturation, harvesting time and processing on the contents of flavonoids.
  
  
  METHODS
  The analysis was performed on a Thermo ODS-2 Hypersil column (4.6 mm x 250 mm, 5 microm) at 26 degrees C with a gradient program of acetonitrile-0.1% H3 PO4 aqueous solution-tetrahydrofuran as the mobile phase and a Diode Array Detector as the detector with the detection wavelength at 274 nm. The flow rate was 1.0 mL x min(-1), and the injection value was 20 microL.
  
  
  RESULTS
  Six flavonoids, baicalin (1), oroxylin A-7-O-glucuronide (2), wogonoside (3), baicalein (4), wogonin (5) and oroxylin A (6), were linear over the selected range with R2 > or = 0.999 3. The average recoveries were between 96.6% -103.0%, and RSD were less then 5.0% (n = 9) for flavonoids 1-6. By analyzing the data obtained, the effect of geographic sources, culturation, harvesting time and processing on the contents of flavonoids were discussed.
  
  
  CONCLUSIONS
  This method is simple, sensitive, reliable and reproducible. It can be used for the quality control of S. baicalensis.
authors.affiliation: State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University Health Science Center, Beijing 100191, China.
authors.forename: Xiqin
authors.initials: X
authors.lastname: Zhou
authors.forename: Qingying
authors.initials: Q
authors.lastname: Zhang
authors.forename: Hong
authors.initials: H
authors.lastname: Liang
authors.forename: Yajie
authors.initials: Y
authors.lastname: Jiang
authors.forename: Xuan
authors.initials: X
authors.lastname: Wang
authors.forename: Bin
authors.initials: B
authors.lastname: Wang
authors.forename: Yuying
authors.initials: Y
authors.lastname: Zhao
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000295:instrumentation / Q000379:methods*; D004365:Drugs, Chinese Herbal / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry*; D031364:Scutellaria baicalensis / Q000737:chemistry*
chemical_list: D004365:Drugs, Chinese Herbal; D005419:Flavonoids