采用差速离心法制备鲫鱼肝微粒体,选择已经建立的肝微粒体系统进行体外孵育,研究有机磷杀虫剂辛硫磷在鲫鱼肝微粒体中的代谢。产物经乙酸乙酯萃取2次,取出有机相于40℃下旋转蒸发至近干,加1 mL甲醇,经高效液相色谱(HPLC)分离测定,液相色谱-电喷雾质谱联用(LC-ESI/MS)鉴定其分子结构,发现了3种代谢产物(M1:二乙基硫代磷酸;M2:四乙基二硫代焦磷酸;M3:辛氧磷),据此推断辛硫磷在鲫鱼肝微粒体(细胞色素P450酶系)的作用下进行了脱硫氧化、水解反应。从而可推断辛硫磷在鲫鱼肝微粒体中的代谢途径和代谢特点,为进一步研究其体内代谢和代谢酶奠定基础。
The liver microsomes were prepared by differential ultracentrifugation for the investigation of in vitro metabolism of phoxim.The metabolites were extracted twice from the reaction solution with ethyl acetate,remove the organic phase to rotary evaporator by near dryness at 40 ℃,then constant volume by 1mL methanol,separated and determined by HPLC,and then identified by HPLC-MS(ESI).Three major metabolites(M1: O,O,O’,O’-tetraethyldithiopyrophosphate,M2: diethylthiophosphate and M3: phoxom) indicated that phoxim underwent desulfur-oxidation and hydrolysis in crucian carp liver microsomes.Therefore,this study deduced the metabolic pathway and metabolic characteristic of phoxim in liver microsomes of crucian carp and laid a solid foundation for further study of its metabolism and metabolic enzymes.