title: Qualitative and quantitative analyses of flavonoids in Spirodela polyrrhiza by high-performance liquid chromatography coupled with mass spectrometry.
abstract: BACKGROUND
  Spirodela polyrrhiza (L.) Schleid. is a traditional Chinese herbal medicine for the treatment of influenza. Despite its wide use in Chinese medicine, no report on quality control of this herb is available so far.
  
  
  OBJECTIVE
  To establish qualitative and quantitative analytical methods by high-performance liquid chromatography (HPLC) coupled with mass spectrometry (MS) for the quality control of S. polyrrhiza.
  
  
  METHODS
  The methanol extract of S. polyrrhiza was analysed by HPLC/ESI-MS(n). Flavonoids were identified by comparing with reference standards or according to their MS(n) (n = 2-4) fragmentation behaviours. Based on LC/MS data, a standardised HPLC fingerprint was established by analysing 15 batches of commercial herbal samples. Furthermore, quantitative analysis was conducted by determining five major flavonoids, namely luteolin 8-C-glucoside, apigenin 8-C-glucoside, luteolin 7-O-glucoside, apigenin 7-O-glucoside and luteolin.
  
  
  RESULTS
  A total of 18 flavonoids were identified by LC/MS, and 14 of them were reported from this herb for the first time. The HPLC fingerprints contained 10 common peaks, and could differentiate good quality batches from counterfeits. The total contents of five major flavonoids in S. polyrrhiza varied significantly from 4.28 to 19.87 mg/g.
  
  
  CONCLUSIONS
  Qualitative LC/MS and quantitative HPLC analytical methods were established for the comprehensive quality control of S. polyrrhiza.
authors.affiliation: The State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, 38 Xueyuan Road, Beijing 100191, China.
authors.forename: Xue
authors.initials: X
authors.lastname: Qiao
authors.forename: Wen-ni
authors.initials: WN
authors.lastname: He
authors.forename: Cheng
authors.initials: C
authors.lastname: Xiang
authors.forename: Jian
authors.initials: J
authors.lastname: Han
authors.forename: Li-jun
authors.initials: LJ
authors.lastname: Wu
authors.forename: De-an
authors.initials: DA
authors.lastname: Guo
authors.forename: Min
authors.initials: M
authors.lastname: Ye
mesh_terms: D047310:Apigenin / Q000032:analysis / Q000737:chemistry; D029064:Araceae / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid / Q000379:methods / Q000592:standards; D004365:Drugs, Chinese Herbal / Q000032:analysis / Q000737:chemistry; D047309:Flavones / Q000032:analysis / Q000737:chemistry; D005419:Flavonoids / Q000032:analysis* / Q000737:chemistry; D005960:Glucosides / Q000032:analysis / Q000737:chemistry; D015394:Molecular Structure; D011786:Quality Control; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods* / Q000592:standards; D047311:Luteolin
chemical_list: D047310:Apigenin; D004365:Drugs, Chinese Herbal; D047309:Flavones; D005419:Flavonoids; D005960:Glucosides; C066408:luteolin-7-glucoside; D047311:Luteolin; C032731:vitexin