液相色谱-串联电喷雾离子阱质谱法鉴定大鼠尿液中药根碱代谢物

目的研究药根碱在大鼠体内的主要代谢产物。方法健康大鼠尾静脉注射12 mg·kg^-1药根碱，收集0～72 h的尿样，尿样经C₁₈小柱固相萃取分离纯化后，经液相色谱-串联电喷雾离子阱质谱(LC-ESI/ITMSⁿ)分析鉴定其中的代谢物。代谢物的结构鉴定主要依据各代谢物与原药的一级质谱电离规律和二级或三级质谱裂解规律间的关联性。结果在大鼠尿样中检测到7种I相代谢产物(如原药的脱氢、脱甲基、羟基化代谢物)及11种II相代谢产物(如甲基化轭合物和葡糖醛酸轭合物)。结论本方法用于大鼠尿样中药根碱的代谢物研究不仅操作简单、快速，而且灵敏度高、专属性强。

Liquid chromatography-tandem electrospray ionization ion trap mass spectrometric assay for the metabolites of jatrorrhizine in rat urine

AIM: To identify the main metabolites of jatrorrhizine in rat urine. METHODS: The rat urine samples were collected 0 - 72 h after ig 12 mg x kg(-1) jatrorrhizine, then the samples were purified through C18 solid-phase extraction cartridge. The purified samples were analyzed by combining liquid chromatography and tandem electrospray ionization ion trap mass spectrometry (LC-ESI/ITMS(n)). Identification and structural elucidation of the metabolites were performed by comparing the changes in molecular masses, retention-times and full scan MS(n) spectra with those of the parent drug. RESULTS: At least seven phase I metabolites (such as de-methyl, de-hydrogen and hydroxyl metabolites) and eleven phase II metabolites (such as glucuronide conjugates and methyl-conjugates) were identified in rat urine. CONCLUSION: The developed LC-ESI/ITMS(n) method is not only simple and rapid but also sensitive and specific for the identification of metabolites of jatrorrhizine in rat urine.