手性衍生化-反相高效液相色谱法测定大鼠肝微粒体中盐酸普罗帕酮对映体及其在代谢研究中的应用

目的　建立鼠肝微粒体中盐酸普罗帕酮消旋体(R/S-PPF)的手性拆分法，以研究大鼠肝微粒体中R/S-PPF体外代谢的立体选择性。方法　用GITC柱前手性衍生化、反相高效液相色谱法拆分R/S-PPF;外标法定量;体外微粒体孵育试验。结果　基线拆分了盐酸普罗帕酮两对映体，容量因子分别为7.9和9.5，分离系数α为1.2，分离度R为1.9，线性范围0.5～320 μg.mL^-1，检测限100 ng.mL^-1，定量限5 μg.mL^-1(RSD<15%)。平均绝对回收率S-PPF为77.1%，R-PPF为76.0%。平均日内、日间精密度均<10%。在DEX和BNF诱导鼠肝微粒体中，PPF的代谢呈显著的立体选择性，在空白对照微粒体中的代谢未呈立体选择性。结论　此法简便、经济，可用于鼠肝微粒体中R/S-PPF代谢的立体选择性研究。

CHIRAL RP-HPLC ASSAY FOR PROPAFENONE ENANTIOMERS IN RAT LIVER MICROSOMAL INCUBATES AND ITS APPLICATION IN VITRO METABOLISM

AIM　To separate propafenone enantiomers in rat liver microsomal incubates and investigate probable stereoselectivity in their N-dealkylation. METHODS　The concentration of each enantiomer in rat liver microsomal incubates was determined through precolumn derivatization with 2,3,4,6-tetra-O-acetyl-β-glucopyranosyl isothiocyanate (GITC), followed by RP-HPLC assay. RESULTS　A baseline separation of propafenone enantiomers was achieved on C₁₈-ODS column, with methanol — water — glacial acetic acid (67∶33∶0.05) as mobile phase. The assay was linear from 0.5 to 320 μg*mL^-1 for each enantiomer, and the limit of detection was 100 ng*mL^-1. The method affords the average recoveries of 77.1% for R-propafenone and 76.0% for S-propafenone. Stereoselectivity was observed for the phase I metabolism of racemic propafenone in dexamethasone, β-naphthoflavone induced rat liver microsomal incubates,but not in controls. CONCLUSION　The method is simple, cheap and can be applied to study the metabolism of R- and S-propafenone in vitro. Stereoselectivity exists in their N-dealkylation.