Novel Cyclic Phosphate Prodrug Approach for Cytochrome P450-activated Drugs Containing an Alcohol Functionality
作者:Kristiina M. Huttunen、Niina Mähönen、Jukka Leppänen、Jouko Vepsäläinen、Risto O. Juvonen、Hannu Raunio、Hanna Kumpulainen、Tomi Järvinen、Jarkko Rautio
DOI:10.1007/s11095-006-9187-y
日期:2007.3.12
A cyclic phosphate prodrug of a descriptive molecule containing an alcohol functionality was designed, synthesized and characterized in vitro as a cytochrome P450 (CYP) -selective prodrug. To achieve efficient CYP-oxidation and prodrug bioconversion, 1,3-cyclic propyl ester of phosphate was designed to have a C4-aryl substituent and synthesized using phosphorus(III) chemistry. The two-step bioconversion of the cyclic phosphate prodrug was evaluated in vitro using human liver microsomes and recombinant CYP enzymes. This cyclic phosphate prodrug underwent initial CYP-catalyzed oxidation and was mainly catalyzed by the CYP3A4 form. The hydroxylated product was slowly converted to a ring-opened intermediate, which subsequently transformed by β-elimination reaction to a free phosphate. The free phosphate was further dephosphorylated by microsomal phosphatases, releasing the parent molecule with a free hydroxyl group. The cyclic phosphate was reasonably stable in buffer solutions at the pH range 1.0−9.0. Since CYP enzymes reside predominantly in the liver and secondarily in the small intestine, the results indicate that cyclic phosphate prodrugs represent a very feasible liver- or intestinal-targeted drug delivery strategy for drug molecules containing an alcohol functionality. This may potentially improve the efficacy and the safety profile of the alcoholic parent drugs.
设计、合成了一种含有醇官能团的描述性分子的环磷酸酯原药,并在体外将其表征为一种细胞色素 P450(CYP)选择性原药。为了实现高效的 CYP 氧化和原药生物转化,设计了具有 C4 芳基取代基的 1,3 环磷酸丙酯,并使用磷(III)化学法进行合成。利用人体肝脏微粒体和重组 CYP 酶对环磷酸酯原药的两步生物转化进行了体外评估。这种环磷酸原药经历了最初的 CYP 催化氧化,主要由 CYP3A4 形式催化。羟化产物缓慢转化为开环中间体,随后通过β-消除反应转化为游离磷酸盐。游离磷酸在微粒体磷酸酶的作用下进一步脱磷酸,释放出带有游离羟基的母分子。环状磷酸在 pH 值为 1.0-9.0 的缓冲溶液中相当稳定。由于 CYP 酶主要存在于肝脏,其次才是小肠,研究结果表明,环磷酸原药是一种非常可行的肝脏或肠道靶向给药策略,适用于含有醇官能团的药物分子。这有可能提高酒精母药的疗效和安全性。