title: A new quantitation method of protodioscin by HPLC-ESI-MS/MS in rat plasma and its application to the pharmacokinetic study.
abstract: A specific high performance liquid chromatography tandem mass spectrometry (HPLC-MS/MS method) was established for determining the concentration of protodioscin (PG) in rat plasma after intragastric administration of its standard form. Ginsenoside Rb1 was selected as the internal standard (IS). The plasma sample was prepared using one-step deproteinization procedure by adding three parts of acetonitrile to precipitate proteins. The chromatographic separation was accomplished on an Inersil ODS-3 C18 column (250 × 4.6 mm, 5 μm) with a mobile phase composed with acetonitrile and water containing 0.1% formic acid under a gradient elution mode at a flow rate of 1 mL min(-1). A 3:1 portion of the eluent after a microsplit was detected on a triple quadrupole tandem mass spectrometer coupled with electrospray ionization (ESI) in positive ion and multiple reaction monitoring (MRM) scanning modes. The mass transitions were selected as 888.1 → 1050.2 for PG and 948.2 → 1110.3 for IS, respectively. After careful validation, the plasma samples were always stable under different storage conditions. These analytical results rendered sensitive, selective, and reliable values by this established method which displayed high accuracy, adequate extracted recoveries, and almost negligible matrix effects. This method was applied to the pharmacokinetic studies on PG level in the rat plasma and its pharmacokinetic effect. The results of our studies suggest that the present method may be a useful tool for further clinical study of PG.
authors.affiliation: College of Pharmacy, Xi'an Jiaotong Univeristy, Xi'an 710061, China.
authors.forename: Xinxin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: College of Pharmacy, Xi'an Jiaotong Univeristy, Xi'an 710061, China.
authors.forename: Zengjun
authors.initials: Z
authors.lastname: Guo
authors.affiliation: Biomedicine Key Laboratory of Shaanxi Province, Northwest University, Xi'an 710069, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: Laboratory of Bioseparation Technology, Biochemistry and Biophysics Center, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, Maryland, USA. Electronic address: itoy@nhlbi.nih.gov.
authors.forename: Yoichiro
authors.initials: Y
authors.lastname: Ito
authors.affiliation: Biomedicine Key Laboratory of Shaanxi Province, Northwest University, Xi'an 710069, China. Electronic address: swj@nwu.edu.cn.
authors.forename: Wenji
authors.initials: W
authors.lastname: Sun
mesh_terms: D000284:Administration, Oral; D000818:Animals; D001774:Blood Chemical Analysis / Q000379:methods*; D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D004144:Diosgenin / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000097:blood / Q000302:isolation & purification / Q000493:pharmacokinetics; D057230:Limit of Detection; D008297:Male; D051381:Rats; D012503:Saponins / Q000008:administration & dosage / Q000097:blood* / Q000302:isolation & purification / Q000493:pharmacokinetics*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013997:Time Factors
chemical_list: D012503:Saponins; C459619:protodioscin; D004144:Diosgenin
keywords: Ginsenoside Rb(1); HPLC–MS/MS; Pharmacokinetics; Protodioscin; Rat plasma