瑞香素在大鼠肝S9中体外代谢研究  

In vitro metabolism of daphnetin in rat liver S9 fractions

作　　者：梁思成[1,2] 葛广波[1] 夏杨柳[1] 齐晓怡[3] 王傲雪[3] 涂彩霞[3] 杨凌[1] 

机构地区：[1]中国科学院大连化学物理研究所药用资源开发研究组,辽宁大连116023 [2]大连医科大学附属第二医院,辽宁大连116027 [3]中国科学院大学,北京100049

出　　处：《药学学报》2017年第2期291-295,共5页Acta Pharmaceutica Sinica

基　　金：国家基础研究计划资助项目(2013CB531805);国家自然科学基金资助项目(81273590;81473181;81402822)

摘　　要：瑞香素给药后在大鼠体内快速代谢消除,但机制仍不清楚。本研究开展瑞香素体外代谢特征分析,鉴定了瑞香素在大鼠肝S9(RLS9)中的代谢产物结构,测定了不同代谢路径的动力学参数。HPLC-DAD-MS检测发现,瑞香素在RLS9中转化为6个代谢产物,包括7-或8-葡糖醛酸和硫酸酯代谢物、8-甲基代谢物及7-硫酸酯-8-甲基代谢物。动力学分析表明,瑞香素在RLS9的葡糖醛酸化和甲基化反应符合米氏动力学,7-O-磺酸化反应和8-O-磺酸化反应分别符合双位点和底物抑制动力学。3条代谢路径中,清除率最大的为磺酸化反应,其次为甲基化和葡糖醛酸化反应。借助体外代谢动力学数据和体外-体内关联方法,预测获得的瑞香素在大鼠体内肝清除率(54.9 m L·min^(-1)·kg^(-1))与文献报道的大鼠体内总清除率(58.5 m L·min^(-1)·kg^(-1))接近。结果表明,肝脏是瑞香素在大鼠体内主要代谢位点。磺酸化、甲基化和葡糖醛酸化反应是瑞香素在大鼠肝脏中主要清除路径。Daphnetin is quickly eliminated in rats after dosing,but the mechanism remains unclear. This study was aimed to investigate the in vitro metabolism of daphnetin using rat liver S9 fractions（RLS9）. The metabolites formed in RLS9 were identified and the kinetic parameters for different metabolic pathways were determined. HPLC-DAD-MS analysis showed that daphnetin was biotransformed to six metabolites,which were identified as 7 or 8 mono-glucuronide and mono-sulfate,8-methylate,and 7-suflo-8-methylate. Methylation and glucuronidation of daphnetin exhibited the Michaelis-Menten kinetic characteristics,whereas the substrate inhibition kinetic and the two-site kinetic were observed for 8-sulfate and 7-sulfate formations. Of the 3 conjugation pathways,the intrinsic clearance rate for sulfation was highest,followed by methylation and glucuronidation. By in vitro-in vivo extrapolation of the kinetic data measured in RLS9,the hepatic clearance were estimated to be 54.9 m L·min^-1·kg^-1 which is comparable to the system clearance（58.5 m L·min^-1·kg^-1） observed in rats. In conclusions,the liver might be the main site for daphnetin metabolism in rats. Sulfation,methylation and glucuronidation are important pathways of the hepatic metabolism of daphnetin in rats.

关 键 词：瑞香素 II相代谢酶 酶动力学 肝清除率 

分 类 号：R917[医药卫生—药物分析学]