LC-MS/MS method for the determination of a new puerarin derivative and its application in pharmacokinetic studies in rats.

To establish a sensitive and rapid liquid chromatographic-tandem mass spectrometry (LC-MS/MS) method for the quantitative analysis of dehydrated puerarin in rat plasma, and its application for pharmacokinetic studies. A plasma sample was pretreated by one-step protein precipitation by the addition of five volumes of methanol. The chromatographic separation was achieved on a Zorbax SB-C18 column (4.6 mm × 150 mm I.D. 5.0 μm, Agilent, USA) at 40 °C at a flow rate of 0.6 mL·min(-1) by an isocratic elution consisting of 10 mmol·L(-1) ammonium acetate in methanol and water containing 0.1% formic acid in a ratio of 20 : 80 (V/V). Detection was performed on a triple quadrupole mass spectrometer in multiple-reaction monitoring (MRM) mode. An atmospheric pressure chemical ionization (APCI) interface in positive ionization mode was used by monitoring the transitions from m/z 399.1→281.0 (dehydrated puerarin) and m/z 271.0→215.0 (internal standard, IS). Calibration curves were linear in the concentration range from 1.50 to 5400 ng·mL(-1), and the lower limit of quantification (LLOQ) was 1.50 ng·mL(-1) in rat plasma. The accuracy and precision values, which were calculated from three different sets of quality control samples analyzed in sextuplicate on three different days, ranged from 95.73% to 103.18%, and from 4.33% to 7.86%, respectively. The method was successfully applied to assess the pharmacokinetics of dehydrated puerarin after oral administration in rats.

Liu AC ，Zhao LX ，Xing J ，Gao J ，Lou HX ... -  《-》

Simultaneous determination of acetylpuerarin and puerarin in rat plasma by liquid chromatography-tandem mass spectrometry: Application to a pharmacokinetic study following intravenous and oral administration.

A rapid and sensitive liquid chromatography-tandem mass spectrometric (LC-MS/MS) method was developed and validated for the simultaneous determination of acetylpuerarin (AP) and its major metabolite puerarin (PUE) in rat plasma using genistein as the internal standard (IS). Plasma samples were pretreated by protein precipitation with a mixture of methanol and acetonitrile. Chromatographic separation was performed on a CAPCELL PAK C18 MGШ column with a mixture of 0.1% formic acid in water and methanol (35:65, v/v) as the mobile phase. The analytes were detected using a tandem mass spectrometer in the positive ionization and multiple-reaction monitoring mode. The ion transition of m/z 669.4→627.3, 417.5→297.6 and 271.3→153.0 was utilized to quantify AP, PUE and the IS, respectively. The calibration curves showed good linearity over the plasma concentration range of 1-2000ng/mL for AP and 2.5-5000ng/mL for PUE. The intra- and inter-day precisions (RSD %) for each analyte were less than 6.91%, and the accuracies ranged from -2.17% to 2.93%. The validated LC-MS/MS method was further successfully applied to a pharmacokinetic study of AP and PUE in rats following intravenous and oral administration.

Sun D ，Xue A ，Wu J ，Zhang B ，Yu J ，Li Q ，Sun C ... -  《-》

HPLC-APCI-MS/MS method for the determination of catalpol in rat plasma and cerebrospinal fluid: application to an in vivo pharmacokinetic study.

Catalpol is a Chinese herb ingredient with potential for the treatment of neurodegenerative disorders. A high-performance liquid chromatography-atmospheric pressure chemical ionization-tandem mass spectrometry (HPLC-APCI-MS/MS) method was developed and validated to investigate the pharmacokinetics and biodistribution of catalpol in both the plasma and cerebrospinal fluid (CSF) of rats. Methanol was used to precipitate the protein from the biosamples, and the supernatant was collected for the assay. A Diamonsil C18 column (150 mm × 4.6 mm, 5 μm) with a mobile phase of methanol-ammonium acetate (20 mM) (50:50, v/v), a 0.6 mL/min flow rate and a total run time of 3 min was used to separate catalpol and aucubin (internal standard, IS). A triple-quadrupole tandem mass spectrometer with an atmospheric pressure chemical ionization (APCI) source in the positive ion mode was operated in the multiple reaction-monitoring (MRM) mode to determine the concentration of catalpol at m/z 380.0-165.0 and that of IS at m/z 364.0-148.9. The linear range was 10-50000 ng/mL for plasma samples and 20-5000 ng/mL for CSF samples. At both the lower limit of quantification (LLOQ) and three levels QC (quality control) concentrations, the RSD was less than 12.9%, and the bias was -10.0% to 7.1%. The extraction recoveries for catalpol ranged from 72.9% to 109.5% from both rat plasma and CSF. The catalpol was administered to rats in 6 mg/kg doses via intravenous (i.v.) injection, and the pharmacokinetics and biodistribution studies were performed in both plasma and CSF. The results demonstrated that catalpol could be transported into the CSF via the AUC(CSF)/AUC(plasma) of 5.8% with a half-life (t(1/2)) of 1.5 h. Overall, the established HPLC-APCI-MS/MS method is rapid and sensitive, and has been successfully used to quantify catalpol in both plasma and CSF.

Wang Q ，Xing M ，Chen W ，Zhang J ，Qi H ，Xu X ... -  《-》

Determination of xanthatin by ultra high performance liquid chromatography coupled with triple quadrupole mass spectrometry: application to pharmacokinetic study of xanthatin in rat plasma.

A sensitive, specific and rapid ultra high performance liquid chromatography tandem mass spectrometry (UHPLC-MS/MS) method has been established to study pharmacokinetic properties of xanthatin. Xanthatin, a compound which belongs to sesquiterpene lactone group, was determined in rat plasma with psoralen as internal standard. Chromatographic separation was performed on an Agilent Zorbax Eclipse plus C18 column (50 mm × 2.1 mm, 3.5 μm) with gradient elution system at a flow rate of 0.3 mL/min. The mobile phase was composed of methanol and 0.1% formic acid water solution. Analysis was performed under a triple-quadruple tandem mass-spectrometer with an electrospray ionization (ESI) source via the multiple reaction monitoring (MRM) mode to determine xanthatin at [M+H](+)m/z 247.3→m/z 205.2 and that of IS at [M+H](+)m/z 187.1→m/z 143.0 within 5 min. The assay method exhibited good separation of xanthatin from the interference of endogenous substances. The lower limit of quantification (LLOQ) was 1 ng/mL, with a good linearity within the concentration range of 1-5000 ng/mL (r=0.9990). Intra-day and inter-day precision RSD was less than 9.27%; intra-day and inter-day accuracy was 88.48% and 102.25% respectively. The extraction recoveries of xanthatin range from 82.12% to 89.55%, and the extraction RSD was less than 9.01%. The established LC-ESI-MS/MS method is rapid and sensitive, which has been successfully applied to quantify xanthatin in rat plasma for the first time.

Yan C ，Li H ，Wu Y ，Xie D ，Weng Z ，Cai B ，Liu X ，Li W ，Chen Z ... -  《-》

Determination of isotoosendanin in rat plasma by liquid chromatography-tandem mass spectrometry: application to pharmacokinetics study.

Deng Z ，Zhong H ，Liu S ，Cui S ，Xie Y ，Yao Q ... -  《-》