乙酰甲喹在斑马鱼中的代谢研究

Metabolism Investigation of Mequindox in Zebrafish

为了阐明乙酰甲喹在水产动物中的代谢过程,本试验采用超高效液相色谱串联四级杆/飞行时间质谱(UPLC-Q/TOF-MS)技术及代谢软件MetabolynxXS自动分析采集功能,研究其在斑马鱼中的主要代谢产物。斑马鱼经药浴摄入乙酰甲喹后,分别采用乙酸乙酯和乙腈提取组织中的乙酰甲喹及代谢物,过0.22μm滤膜后经UPLC-Q/TOF-MS分析,通过比较试验组和对照组的色谱图新增色谱峰,确定代谢产物的数量;通过比较乙酰甲喹标准品及代谢产物的精准MS/MS质谱图,确定代谢产物的化学结构,并推测其可能的代谢途径。结果显示,乙酰甲喹在斑马鱼中的代谢产物较少,主要是脱氧代谢物,包括单脱氧代谢物N1-脱氧乙酰甲喹(1-DMEQ)、N4-脱氧乙酰甲喹(4-DMEQ)及双脱氧代谢物N1,N4-双脱氧乙酰甲喹(1,4-BDMEQ),代谢途径主要为N→O基团还原。残留消除规律研究发现,乙酰甲喹消除较快,4h降至初始浓度一半以下,并呈现逐渐降低的趋势;其3种代谢产物浓度均呈现先增高后降低的趋势,其中2种单脱氧代谢物在给药后2h浓度达到最高,8h降至最高浓度一半以下,双脱氧代谢物在给药后4h药物浓度达到最高,12h降至最高浓度一半以下,结果表明,乙酰甲喹在斑马鱼中代谢消除速率较快。上述研究结果可为乙酰甲喹在其他水产食品动物中的代谢研究提供参考,并为水产动物源性食品安全的监控及药代动力学研究提供技术支持。

This study was aimed to illustrate the metabolic pathway of mequindox(MEQ)in aquatic animal.Ultra-high performance liquid chromatography tandem time-of-flight mass spectrum(UPLC-Q/TOF-MS)and metabolism analysis software Metabolynx XS were adopted in this research,and zebrafish was adopted as aquatic model animal for MEQ metabolism investigation.After dipping with MEQ,zebrafish tissues were collected and MEQ metabolites were extracted with ethyl acetate and acetonitrile in turn.Then samples were filter through 0.22μm filter membrane for further UPLC-Q/TOF-MS analysis.The number of metabolites could be confirmed according to the newly increased chromatographic peak by comparing the experimental group and the control.The chemical structure of metabolites could be confirmed according to the accurate mass spectrum by comparing the metabolites and the MEQ standard.The results showed that the major metabolic pathway of MEQ in zebrafish was N→O group reduction.Only three metabolites were identified,including N1-deoxymequindox(1-DMEQ),N4-deoxymequindox(4-DMEQ)and N1,N4-bisdeoxymequindox(1,4-BDMEQ).The depletion rule of MEQ and major metabolites in zebrafish was investigated.It was found that the concentration of MEQ reduced after administration,and it was less than the half of the highest concentration after 4 h.As to the three metabolites,the concentration first increased and then decreased.The highest concentration of 1-DMEQ and 4-DMEQ was at 2 h after administration,and then it was less than the half of the highest concentration after 8 h.For another metabolite 1,4-BDMEQ,the highest concentration was at 4 h after administration,and it was less than the half of the highest concentration after 12 h.This study would contribute to further control of aquatic animal derived food safety.In addition,the results would be benefit for the metabolism and pharmacokinetic investigation of MEQ in other aquatic food animal.