Watanabe Takaho, Morisseau Christophe, Newman John W, Hammock Bruce D
Department of Entomology & Cancer Research Center, University of California, Davis, CA 95616, USA.
Drug Metab Dispos. 2003 Jul;31(7):846-53. doi: 10.1124/dmd.31.7.846.
The metabolism of the soluble epoxide hydrolase (sEH) inhibitor, 1-cyclohexyl-3-dodecyl-urea (CDU), was studied in rat and human hepatic microsomes. The microsomal metabolism of CDU enhanced sEH inhibition potency of the reaction mixture and resulted in the formation of several metabolites. During the course of this study, a sensitive and specific high-performance liquid chromatography with tandem mass spectrometry analytical method was developed to investigate simultaneously the production of these metabolites. In both rat and human hepatic microsomes, CDU was ultimately transformed into the corresponding omega-carboxylate; however, the rodent tissue appeared to perform this transformation more rapidly. After a 60-min incubation in rat hepatic microsomes, the percentage of residual CDU, the omega-carboxylate, and the intermediary omega-hydroxyl were about 20%, 20%, and 50%, respectively. Carbon monoxide inhibited the metabolism of CDU by rat hepatic microsomes, suggesting that the initial step is catalyzed by cytochrome P450. Further metabolism was enhanced by the addition of NAD, suggesting that dehydrogenases are associated with intermediate metabolic steps. Regardless, the ultimate product of microsomal metabolism, 12-(3-cyclohexyl-ureido)-dodecanoic acid, is also an excellent sEH inhibitor with several hundred-fold higher solubility, supporting the hypothesis that CDU has prodrug characteristics. These findings will facilitate the rational design and optimization of sEH inhibitors with better physical properties and improved metabolic stability.
在大鼠和人肝微粒体中研究了可溶性环氧化物水解酶（sEH）抑制剂1-环己基-3-十二烷基脲（CDU）的代谢。CDU的微粒体代谢增强了反应混合物的sEH抑制效力，并导致形成几种代谢产物。在本研究过程中，开发了一种灵敏且特异的高效液相色谱-串联质谱分析方法，以同时研究这些代谢产物的产生。在大鼠和人肝微粒体中，CDU最终都转化为相应的ω-羧酸盐；然而，啮齿动物组织似乎能更快地进行这种转化。在大鼠肝微粒体中孵育60分钟后，残留CDU、ω-羧酸盐和中间产物ω-羟基的百分比分别约为20%、20%和50%。一氧化碳抑制大鼠肝微粒体对CDU的代谢，表明初始步骤由细胞色素P450催化。添加NAD可增强进一步的代谢，表明脱氢酶与中间代谢步骤相关。无论如何，微粒体代谢的最终产物12-（3-环己基脲基）-十二烷酸也是一种出色的sEH抑制剂，其溶解度高出数百倍，支持了CDU具有前药特性的假设。这些发现将有助于合理设计和优化具有更好物理性质和更高代谢稳定性的sEH抑制剂。
