title: [Structures of leucogen and its related substances in solution state].
abstract: OBJECTIVE
  To study the four diastereomers of leucogen and structure of the related substances.
  
  
  METHODS
  LC-DAD, LC-MS/MS and LC- 1H NMR were used. LC was carried out with a Phenomnex Luna C18 (250 mm x 4.60 mm ID, 5 microm) column and a mobile phase of water-acetonitrile-glacial acetic acid (58:42: 0.3).
  
  
  RESULTS
  The structures of leucogen and its related substances were identified. Leucogen and the related substances were found to have four diastereomers in solution state separately. The stability and transformation of the four diastereomers were analyzed and 3R4S5R was found to be more stable than the others according to quantum calculations.
  
  
  CONCLUSIONS
  Leucogen have four diastereomers in solution state and it can transform from one diastereomer to the others, and the 3R4S5R is more stable than the others.
authors.affiliation: Department of Pharmaceutical Analysis, China Pharmaceutical University, Nanjing 210009, China.
authors.forename: Xiu-wen
authors.initials: XW
authors.lastname: Zheng
authors.forename: Wen
authors.initials: W
authors.lastname: Qian
authors.forename: Tai-jun
authors.initials: TJ
authors.lastname: Hang
authors.forename: Hai-bo
authors.initials: HB
authors.lastname: Ma
authors.forename: Zheng-xing
authors.initials: ZX
authors.lastname: Zhang
mesh_terms: D002853:Chromatography, Liquid; D009682:Magnetic Resonance Spectroscopy; D015394:Molecular Structure; D011789:Quantum Theory; D012996:Solutions; D021241:Spectrometry, Mass, Electrospray Ionization; D013237:Stereoisomerism; D053778:Thiazolidines / Q000032:analysis / Q000737:chemistry*
chemical_list: D012996:Solutions; D053778:Thiazolidines; C001176:Leyk