Considering the frequent use of netupitant in polytherapy,the elucidation of its oxidative metabolization pattern is of major importance.However,there is a lack of published research on the redox behavior of this nove...Considering the frequent use of netupitant in polytherapy,the elucidation of its oxidative metabolization pattern is of major importance.However,there is a lack of published research on the redox behavior of this novel neurokinin-1 receptor antagonist.Therefore,this study was performed to simulate the intensive hepatic biotransformation of netupitant using an electrochemically driven method.Most of the known enzyme-mediated reactions occurring in the liver(i.e.,N-dealkylation,hydroxylation,and Noxidation)were successfully mimicked by the electrolytic cell using a boron-doped diamond working electrode.The products were separated by reversed-phase high-performance liquid chromatography and identified by high-resolution mass spectrometry.Aside from its ability to pinpoint formerly unknown metabolites that could be responsible for the known side effects of netupitant or connected with any new perspective concerning future therapeutic indications,this electrochemical process also represents a facile alternative for the synthesis of oxidation products for further in vitro and in vivo studies.展开更多
Objective To develop a liquid chromatography technique coupled with tandem mass spectrometry (LC-MS/MS) for simultaneous determination of four active catechins EGCG, ECG, EGC, and EC of tea polyphenols (TP) in rat pla...Objective To develop a liquid chromatography technique coupled with tandem mass spectrometry (LC-MS/MS) for simultaneous determination of four active catechins EGCG, ECG, EGC, and EC of tea polyphenols (TP) in rat plasma in order to further study its multi-component pharmacokinetics. Methods Following a single step liquid-liquid extraction of plasma samples with ethyl acetate, the four catechins were separated on a Hypersil ODS C18 column using an isocratic mobile phase composed of methanol-water (30︰70). The detection using a mass spectrometer was performed under negative ESI in the MRM mode. The analytes were identified by reference to both MRM and tR values and quantified using peak area internal standard method. Results The method was shown to be specific without interference from matrix, metabolites, and impurities present in TP raw material and to be sensitive with LOD and LOQ of 1.5 and 10 ng/mL (EGCG) as well as 0.75 and 5 ng/mL (ECG, EGC, and EC). A good linearity was obtained over a wide range of 10-10 000 ng/mL for EGCG and 5-5000 ng/mL for other three catechins (r > 0.996). The method was validated to be reproducible and reliable, as evidenced by intra-batch and inter-batch precision of less than 10% and 11%, accuracy of 97.13%-106.05% and 99.22%-103.14%, respectively. The recovery of extraction ranged from 72.74% to 89.13%, matrix effect from 88.76% to 105.97% for four catechins. The method was successfully used to study the pharmacokinetics of TP iv administered to rats at a dose of 100 mg/kg. Conclusion This method is shown to completely meet requirements for the multi-component pharmacokinetic study of TP in rats.展开更多
基金The authors gratefully acknowledged the financial support for part of this work by the German Research Foundation(DFG,Grant No.:KA 1093/7-2,Bonn,Germany)as well as Iuliu Hațieganu University(Internal Grant No.:5200/19/01.03.2017)a grant of the Romanian Ministry of Education and Research,CCCDI-UEFISCDI(Project No.:PNe-Ⅲ-P2-2.1-PED-2019-5473)within PNCDIⅢ.
文摘Considering the frequent use of netupitant in polytherapy,the elucidation of its oxidative metabolization pattern is of major importance.However,there is a lack of published research on the redox behavior of this novel neurokinin-1 receptor antagonist.Therefore,this study was performed to simulate the intensive hepatic biotransformation of netupitant using an electrochemically driven method.Most of the known enzyme-mediated reactions occurring in the liver(i.e.,N-dealkylation,hydroxylation,and Noxidation)were successfully mimicked by the electrolytic cell using a boron-doped diamond working electrode.The products were separated by reversed-phase high-performance liquid chromatography and identified by high-resolution mass spectrometry.Aside from its ability to pinpoint formerly unknown metabolites that could be responsible for the known side effects of netupitant or connected with any new perspective concerning future therapeutic indications,this electrochemical process also represents a facile alternative for the synthesis of oxidation products for further in vitro and in vivo studies.
文摘Objective To develop a liquid chromatography technique coupled with tandem mass spectrometry (LC-MS/MS) for simultaneous determination of four active catechins EGCG, ECG, EGC, and EC of tea polyphenols (TP) in rat plasma in order to further study its multi-component pharmacokinetics. Methods Following a single step liquid-liquid extraction of plasma samples with ethyl acetate, the four catechins were separated on a Hypersil ODS C18 column using an isocratic mobile phase composed of methanol-water (30︰70). The detection using a mass spectrometer was performed under negative ESI in the MRM mode. The analytes were identified by reference to both MRM and tR values and quantified using peak area internal standard method. Results The method was shown to be specific without interference from matrix, metabolites, and impurities present in TP raw material and to be sensitive with LOD and LOQ of 1.5 and 10 ng/mL (EGCG) as well as 0.75 and 5 ng/mL (ECG, EGC, and EC). A good linearity was obtained over a wide range of 10-10 000 ng/mL for EGCG and 5-5000 ng/mL for other three catechins (r > 0.996). The method was validated to be reproducible and reliable, as evidenced by intra-batch and inter-batch precision of less than 10% and 11%, accuracy of 97.13%-106.05% and 99.22%-103.14%, respectively. The recovery of extraction ranged from 72.74% to 89.13%, matrix effect from 88.76% to 105.97% for four catechins. The method was successfully used to study the pharmacokinetics of TP iv administered to rats at a dose of 100 mg/kg. Conclusion This method is shown to completely meet requirements for the multi-component pharmacokinetic study of TP in rats.
