title: Identification of three sulfate-conjugated metabolites of berberine chloride in healthy volunteers' urine after oral administration.
abstract: OBJECTIVE
  To identify the structure of unknown metabolites of berberine (Ber) in human urine after oral administration.
  
  
  METHODS
  Urine samples were obtained from 5 volunteers after they orally took Ber chloride 0.9 g per day for three days. Metabolites in urine samples were isolated and purified by polyporous resin column chromatography. The individual metabolites were identified mainly using electrospray ionization mass spectroscopy (ESI-MS) and proton nuclear magnetic resonance (1H NMR) spectroscopy.
  
  
  RESULTS
  Three unknown metabolites (M1, M2, and M3) were isolated. They were susceptible to arylsufatase. ESI-MS measurements of M1, M2, and M3 produced quasimolecular ions [M+H]+, m/z 17.9, 404.0, and 402.0 respectively. Especially, each of them produced a characteristic protonated ion [M-80+H]+, which can be ascribed as quasimolecular ions lost a SO3 fragment. 1H NMR spectra of the metabolites were also obtained and each of 1H signals was assigned.
  
  
  CONCLUSIONS
  Structures of M1, M2, and M3 were firmly identified as jatrorrhizine-3-sulfate, demethyleneberberine-2-sulfate, and thalifendine-10-sulfate, and the major metabolite was M2.
authors.affiliation: State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031,China.
authors.forename: Jun-Fang
authors.initials: JF
authors.lastname: Pan
authors.forename: Chen
authors.initials: C
authors.lastname: Yu
authors.forename: Da-Yuan
authors.initials: DY
authors.lastname: Zhu
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Jia-Feng
authors.initials: JF
authors.lastname: Zeng
authors.forename: Shan-Hao
authors.initials: SH
authors.lastname: Jiang
authors.forename: Jian-Ying
authors.initials: JY
authors.lastname: Ren
mesh_terms: D000328:Adult; D000930:Antidiarrheals / Q000378:metabolism / Q000652:urine; D001599:Berberine / Q000031:analogs & derivatives / Q000032:analysis* / Q000378:metabolism* / Q000493:pharmacokinetics / Q000652:urine*; D006801:Humans; D009682:Magnetic Resonance Spectroscopy; D008297:Male; D021241:Spectrometry, Mass, Electrospray Ionization; D013431:Sulfates / Q000378:metabolism*
chemical_list: D000930:Antidiarrheals; D013431:Sulfates; C055785:jatrorrhizine; D001599:Berberine; C477156:thalifendine; C477155:demethyleneberberine