title: Simultaneous determination of tetrahydropalmatine, protopine, and palmatine in rat plasma by LC-ESI-MS and its application to a pharmacokinetic study.
abstract: A sensitive and specific liquid chromatography-electrospray ionization-mass spectrometry (LC-ESI-MS) method has been developed and validated for the simultaneous quantification of tetrahydropalmatine, protopine and palmatine in rat plasma using phenacetin as the internal standard (IS). Two hundred microliters plasma samples were extracted by dichloromethane under a strong basic condition. The analytes were separated by a C18 column and detected with a single quadrupole mass spectrometer. The used mobile phase was acetonitrile-water (40:60, v/v) containing 5mM ammonium acetate and 0.2% glacial acetic acid. Detection was carried out by positive electrospray ionization in selected ion reaction (SIR) mode at m/z 356.6 for tetrahydropalmatine, 354.6 for protopine, 352.6 for palmatine and 180.4 for the IS, respectively. The method was validated over the concentration range of 1.00-500ngmL(-1) and the lower limit of quantification (LLOQ) was 1.00ngmL(-1) for all three analytes. The intra- and inter-day precision values were less than 9% relative standard deviation (R.S.D.), and the relative error ranged from -7.4 to 4.8%. The extraction recoveries were on average 91.42% for tetrahydropalmatine, 84.75% for protopine, 57.26% for palmatine, and 83.18% for IS. The validated method was successfully applied to a pharmacokinetic study of tetrahydropalmatine, protopine and palmatine in rats after oral administration of Rhizoma Corydalis Decumbentis extract.
authors.affiliation: Department of Pharmacy, Shenyang Northern Hospital, Shenyang 110016, China.
authors.forename: Hongda
authors.initials: H
authors.lastname: Ma
authors.forename: Yongjun
authors.initials: Y
authors.lastname: Wang
authors.forename: Tao
authors.initials: T
authors.lastname: Guo
authors.forename: Zhonggui
authors.initials: Z
authors.lastname: He
authors.forename: Xinyu
authors.initials: X
authors.lastname: Chang
authors.forename: Xiaohui
authors.initials: X
authors.lastname: Pu
mesh_terms: D000042:Absorption; D000818:Animals; D019540:Area Under Curve; D053119:Benzophenanthridines / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D001600:Berberine Alkaloids / Q000097:blood* / Q000737:chemistry / Q000493:pharmacokinetics; D002138:Calibration; D002853:Chromatography, Liquid / Q000295:instrumentation / Q000379:methods; D031311:Corydalis / Q000737:chemistry; D004355:Drug Stability; D004356:Drug Storage; D004365:Drugs, Chinese Herbal / Q000493:pharmacokinetics*; D005615:Freezing; D017408:Guidelines as Topic; D006207:Half-Life; D008297:Male; D013058:Mass Spectrometry / Q000379:methods*; D008516:Medicine, Chinese Traditional; D015394:Molecular Structure; D010602:Pharmacopoeias as Topic; D010936:Plant Extracts / Q000737:chemistry; D018517:Plant Roots / Q000737:chemistry; D011208:Powders; D051381:Rats; D017208:Rats, Wistar; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*
chemical_list: D053119:Benzophenanthridines; D001600:Berberine Alkaloids; D004365:Drugs, Chinese Herbal; D010936:Plant Extracts; D011208:Powders; C014215:tetrahydropalmatine; C005413:palmatine; C009093:protopine