title: Qualitative and quantitative analysis of flavonoids in Sophora tonkinensis by LC/MS and HPLC.
abstract: OBJECTIVE
  To develop analytical methods for the identification and determination of the flavonoids in Sophora tonkinensis for comprehensive quality evaluation.
  
  
  METHODS
  An HPLC-DAD-ESI-MS method was used for the separation and characterization of the flavonoids in S. tonkinensis, and a liquid chromatographic method was employed to simultaneously determine five major active flavonoids in this crude drug.
  
  
  RESULTS
  Seventeen flavonoids were identified, among which, seven were unambiguously identified as trifolirhizin, quercetin, formononetin, macckiain, kurarinone, sophoranone, and sophoranochromene by comparing their retention times, and UV and MS spectra with those of the authentic compounds, and the other ten flavonoids were tentatively identified by comparing their UV and MS/MS spectra with those of literature data. Furthermore, five major active flavonoids, including trifolirhizin, quercetin, maackiain, sophoranone, and sophoranochromene were determined in S. tonkinensis. All calibration curves expressed good linearity (r > 0.999 8) within the test ranges, and the recovery from this method was 96.40%-104.43%. The developed HPLC method was successfully applied to quantitatively determine the five flavonoids in seventeen samples of S. tonkinensis.
  
  
  CONCLUSIONS
  The developed method rapidly characterized the bioactive flavonoids of S. tonkinensis, and could be readily utilized to enhance the quality assurance approaches for this traditional Chinese medicine.
authors.affiliation: Department of Pharmacognosy, School of Pharmacy, Fudan University, Shanghai 201203, China.
authors.forename: Chang-Ming
authors.initials: CM
authors.lastname: He
authors.affiliation: Department of Pharmacognosy, School of Pharmacy, Fudan University, Shanghai 201203, China.
authors.forename: Zhi-Hong
authors.initials: ZH
authors.lastname: Cheng
authors.affiliation: Department of Pharmacognosy, School of Pharmacy, Fudan University, Shanghai 201203, China. Electronic address: dfchen@shmu.edu.cn.
authors.forename: Dao-Feng
authors.initials: DF
authors.lastname: Chen
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D005419:Flavonoids / Q000737:chemistry*; D015394:Molecular Structure; D010936:Plant Extracts / Q000737:chemistry*; D029909:Sophora / Q000737:chemistry*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D005419:Flavonoids; D010936:Plant Extracts
keywords: Flavonoids; HPLC; Identification; LC/MS; Quantification; Sophora tonkinensis