title: Transformation of astragalosides from radix astragali under acidic, neutral, and alkaline extraction conditions monitored by LC-ESI-TOF/MS.
abstract: OBJECTIVE
  To reveal the profile of astragalosides for better quality evaluation of Radix Astragali, this study was aimed to investigate the transformation of astragalosides under different conditions.
  
  
  METHODS
  Seven major astragalosides were selected for evaluation under acidic, neutral and alkaline conditions. The transformation in real plant samples was also examined and the products were characterized by LC-ESI-TOF/MS.
  
  
  RESULTS
  In weak acidic solution, all of the astragalosides are stable. In addition, the transformation ratios of the astragalosides under neutral and alkaline conditions were also obtained.
  
  
  CONCLUSIONS
  In neutral solution, malonylastragaloside I was transformed to astragaloside I; and in alkaline solution, substituent group(s) in the xylose moiety of all the astragalosides were eliminated. Since astragalosdie IV is the basic skeleton structure of the astrgalosides, it is a common transformation product of other astragalosides.
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Chu
authors.initials: C
authors.lastname: Chu
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: E-Hu
authors.initials: EH
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China. Electronic address: fleude@126.com.
authors.forename: Lian-Wen
authors.initials: LW
authors.lastname: Qi
authors.affiliation: State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, China. Electronic address: liping2004@126.com.
authors.forename: Ping
authors.initials: P
authors.lastname: Li
mesh_terms: D027883:Astragalus Plant / Q000737:chemistry*; D002851:Chromatography, High Pressure Liquid; D004365:Drugs, Chinese Herbal / Q000737:chemistry* / Q000302:isolation & purification; D006863:Hydrogen-Ion Concentration; D015394:Molecular Structure; D018517:Plant Roots / Q000737:chemistry*; D053719:Tandem Mass Spectrometry; D014315:Triterpenes / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D004365:Drugs, Chinese Herbal; D014315:Triterpenes
keywords: Astragalosides; LC-TOF/MS; Radix Astragali; Transformation