title: HPLC and LC-MS analysis of sinomenine and its application in pharmacokinetic studies in rats.
abstract: OBJECTIVE
  To improve and validate analytical methods based on HPLC and liquid chromatography coupled to electrospray ionization tandem mass spectrometry (LC-ESI-MS/MS) for the quantitative measurement of sinomenine in rat plasma and brain tissue.
  
  
  METHODS
  The separation of analytes and the internal standard (IS), chloramphenicol, was performed on an Agilent TC-C18 column (250×4.6 mm, 5 μm). Blood samples were measured with a Surveyor photodiode array (PDA) detector at a wavelength of 263 nm. The LCQ DECA XP(Plus) mass spectrometer was operated in the multiple reactions monitoring mode using positive electrospray ionization, and the transition from the precursor ion (m/z 279) to the product ion (m/z 224) for sinomenine was measured in brain tissue.
  
  
  RESULTS
  Measurements were linear over the concentration range of 0.1-100 μg/mL for sinomenine in plasma and over the range of 0.01-5.00 μg/g for sinomenine in brain tissue. The intra- and inter-day variabilities were less than 10% of the relative standard deviation (RSD), and the extraction and recovery of sinomenine was 72.48%-80.26% from plasma and 73.75%-80.26% from brain tissue. The limit of quantification (LOQ) was 0.1 μg/mL for plasma, and 0.01 μg/g for brain tissue. Identification of sinomenine was reproducible at 0.5, 5, and 50 μg/mL in the plasma and at 0.05, 0.50, and 2.00 μg/g in brain tissue. The concentration of sinomenine measured in brain tissue after a single ip dose had a neuroprotective effect on H₂O₂-induced injury in PC12 cells in vitro.
  
  
  CONCLUSIONS
  Our methods offered a sensitivity within a wide linear concentration range for sinomenine. These methods were successfully applied to evaluate sinomenine pharmacokinetics over time in rat brain tissue after a single ip dose of 30 mg/kg.
authors.affiliation: Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China.
authors.forename: Li-hong
authors.initials: LH
authors.lastname: Long
authors.forename: Peng-fei
authors.initials: PF
authors.lastname: Wu
authors.forename: Xiang-long
authors.initials: XL
authors.lastname: Chen
authors.forename: Zui
authors.initials: Z
authors.lastname: Zhang
authors.forename: Yu
authors.initials: Y
authors.lastname: Chen
authors.forename: Yi-yong
authors.initials: YY
authors.lastname: Li
authors.forename: You
authors.initials: Y
authors.lastname: Jin
authors.forename: Jian-guo
authors.initials: JG
authors.lastname: Chen
authors.forename: Fang
authors.initials: F
authors.lastname: Wang
mesh_terms: D000818:Animals; D001921:Brain / Q000378:metabolism; D002138:Calibration; D018929:Cell Culture Techniques; D002470:Cell Survival / Q000187:drug effects; D002851:Chromatography, High Pressure Liquid; D005260:Female; D006861:Hydrogen Peroxide / Q000633:toxicity; D008297:Male; D009019:Morphinans / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology; D018696:Neuroprotective Agents / Q000032:analysis* / Q000097:blood / Q000493:pharmacokinetics* / Q000494:pharmacology; D016877:Oxidants / Q000633:toxicity; D016716:PC12 Cells; D051381:Rats; D017208:Rats, Wistar; D015203:Reproducibility of Results; D021241:Spectrometry, Mass, Electrospray Ionization; D014018:Tissue Distribution
chemical_list: D009019:Morphinans; D018696:Neuroprotective Agents; D016877:Oxidants; C009271:sinomenine; D006861:Hydrogen Peroxide