The Pharmacokinetic Study Of Alkaloids Of Zanthoxylum Nitidum(Roxb.)DC.in Rats

Objective Zanthoxylum nitidum(Roxb.)DC(Rutaceae),called “Liangmianzhen” in china,is used traditionally for several medicinal purposes.Its pharmacological effect has been primarily attributed to the presence of a number of alkaloids.However,due to lack of metabolism research,its main bioactive alkaloids in vivo are still unknown.The aim of this study was the qualitative and quantitative analysis of bioactive alkaloids in Zanthoxylum nitidum in vivo and in vitro systematically and comprehensively.Methods 1.Characterization of main alkaloids of Zanthoxylum nitidum decoction by UPLC-Q-TOF-MSA systematic method based on ultra-performance liquid chromatography /quadrupole-time-of-flight mass spectrometry(UPLC-Q-TOF-MS)technique combined with Peak View software was developed to speculate the main alkaloids in Zanthoxylum nitidum decoction.2.Metabolic profile of magnoflorine??-allocryptopine and skimmianine in rats determined by UPLC-Q-TOF-MSA UPLC-Q-TOF-MS/MS was utilized to investigate the in vivo metabolic profile of magnoflorine ? ?-allocryptopine and skimmianine in rats,repectivly.The metabolites were predicted using Metabolite PilotTM software.These predicted metabolites were further analyzed by MS2 spectra,and compared with the detailed fragmentation pathway of the standard and literature data.3.Characterization of main alkaloids and their metabolites of Zanthoxylum nitidum decoction in rat by UPLC-Q-TOF-MSA UPLC-Q-TOF-MS/MS was utilized to investigate the in vivo metabolic profile of Zanthoxylum nitidum decoction in rat plasma,urine and feces,repectivly.The prototype were identified by comparing with the components in Zanthoxylum nitidum decoction.The metabolites were predicted using Metabolite PilotTM software.These predicted metabolites were further compared with that of single compounds.4.Pharmacokinetics study of magnoflorine? ?-allocryptopine and skimmianine after oral administration of the Zanthoxylum nitidum decoctionA HPLC–MS/MS method was developed for analysis of magnoflorine??-allocryptopine and skimmianine in rat plasma.The test was performed by using positive ion electrospray ionization.The method was applied in a PK study of magnoflorine??-allocryptopine and skimmianine after oral administration of Zanthoxylum nitidum decoction.Results1.Characterization of main alkaloids of Zanthoxylum nitidum decoction by UPLC-Q-TOF-MSA total of 47 alkaloid components were tentatively detected in Zanthoxylum nitidum decoction,and 16 alkloids were reported for the first time.All components were identified including 8 aporphine alkloids,4 protopine alkloids,6 benzyl isoquinoline,2 four hydrogen protoberberine alkaloids,4 protoberberine alkaloids,12 benzo alkaloids,9 quinoline alkaloids and 2 other alkaloids.2.Metabolic profile of magnoflorine??-allocryptopine and skimmianine in rats determined by UPLC-Q-TOF-MSA total of 8 metabolites were identified in rat plasma,urine and fece samples after oral administration of magnoflorine.The phase ? metabolic pathways consist of O-demethylation,didemethylation,hydroxylation,dehydrogenation and ketonigation.The phase ? metabolic pathways consist of methylation.A total of 25 metabolites were identified in rat plasma,urine and fece samplesafter oral administration of?-allocryptopine.The metabolic pathways consist of O-demethylation,didemethylation,hydroxylation,demethylenation,sulfate conjugationand glucuronide conjugation.The methylenedioxy group and the vicinal methoxyl group were main metabolic soft.A total of 16 metabolites were identified for the first time in rat plasma,urine and fece samples after oral administration of skimmianine.The metabolic pathways consist of O-demethylation,didemethylation,hydroxylation,epoxidation of olefin on its furan ringand followed by the hydrolysis of epoxide ring,sulfate conjugation and glucuronide conjugation.Among these metabolites,the major metabolite was formed through epoxidation of 2,3-olefinic followed by the hydrolysis of its epoxide ring.The next one was C7-O-demethylation products of skimmianine.3.Characterization of main alkaloids and their metabolites of Zanthoxylum nitidum decoction in rat by UPLC-Q-TOF-MSA total of 84 metabolites were identified for the first time in rat plasma,urine and fece samplesafter oral administration of Zanthoxylum nitidum decoction,including 46 prototypes and 38 metabolites.42,63,61 compounds were observed in the rats plasma,urine and feces.4.Pharmacokinetics study of magnoflorine??-allocryptopine and skimmianine after oral administration of the Zanthoxylum nitidum decoctionGood linearities obseverd were as follows: the concentration range from 2 to 200 ng/ml for magnoflorine and ?-allocryptopine,0.5 to 50 ng/ml for skimmianine.The precisions and the accuracy were satisfied.The PK results shows magnoflorine??-allocryptopine and skimmianine were absorbed rapidly,?-allocryptopine and skimmianine were eliminated quickly.ConclusionIn this paper,a method based on ultra-performance liquid chromatography/quadrupole time-of-flight mass spectrometry(UPLC-QTOF-MS)technique combined with Peak View and Metabolite PilotTM software was developed,the method was successful applied to ivestigate the main alkaloids in Zanthoxylum nitidum decoction in vitro and in vivo systematicly and comprdhensively;and a LC-MS/MS method was developed for the quantification of 3 alkloids in rats plasma,the PK properties was obtained for the first time of Zanthoxylum nitidum in rats.The results are important for clarifying efficacy material basis of Zanthoxylum nitidum decoction,and provide a basis for the further study of Zanthoxylum nitidum.