Optical inversion of (2R)- to (2S)-isomers of 2-(4-(2-oxocyclopentylmethyl)-phenyl)propionic acid (loxoprofen), a new anti-inflammatory agent, and its monohydroxy metabolites in the rat.
作者:HISOMU NAGASHIMA、YORIHISA TANAKA、HIDETOSHI WATANABE、RYOZO HAYASHI、KATSURO KAWADA
DOI:10.1248/cpb.32.251
日期:——
Enantiomer ratios of 2-[4-(2-oxocyclopentylmethyl) phenyl] propionic acid (loxoprofen) and its monohydroxy metabolites in plasma of rats were determined by high performance liquid chromatography (HPLC) after derivatization with the chiral reagent, (1S)-1-(4-dimethylaminonaphthalen-1-yl) ethylamine. The ratios of (2S)-to (2R)-isomers of the parent acid and 2-[4-(trans-2-hydroxycyclopentylmethyl) phenyl] propionic acid (trans-alcohol) increased rapidly with time after oral administration of racemic and (2R)-loxoprofen, while the (2S)-configuration remained completely intact after dosing with (2S)-isomer. The results clearly indicate the occurrence of irreversible optical inversion of (2R)-to (2S)-loxoprofen in rats. The administration of trans-and cis-alcohols showed that : (1) the optical inversion also occurs in these monohydroxy metabolites, (2) the cis-alcohol is easily converted to the transalcohol through the parent acid, but the latter is not converted to the former.
用手性试剂(1S)-1-(4-二甲基氨基萘-1-基)乙胺衍生后,采用高效液相色谱法测定了大鼠血浆中2-[4-(2-氧代环戊基甲基)苯基]丙酸(loxoprofen)及其单羟基代谢物的对映体比率。口服外消旋和(2R)-洛索洛芬后,母酸和 2-[4-(反式-2-羟基环戊基甲基)苯基]丙酸(反式醇)的(2S)-异构体与(2R)-异构体之比随着时间的推移迅速增加,而(2S)-异构体在服用(2S)-异构体后仍完全保持不变。这些结果清楚地表明,大鼠体内的(2R)-洛索洛芬与(2S)-洛索洛芬发生了不可逆的光学反转。反式醇和顺式醇的给药表明:(1) 这些单羟基代谢物也会发生光学反转;(2) 顺式醇很容易通过母酸转化为反式醇,但后者不会转化为前者。