目的　用固相萃取 核磁共振氢谱法研究大鼠尿液中R (- ) 布洛芬代谢产物及异构体的转化。方法　将服用R (- ) 布洛芬后 0～ 2 4h大鼠尿液经固相萃取柱处理、核磁共振氢谱测定代谢产物的结构。结果　尿液中含有 4个主要代谢产物 :2 ’ 羟基 布洛芬及其葡糖苷酸结合物、1’ 羧基 布洛芬葡糖苷酸和布洛芬葡糖苷酸。后两者为非对映异构体混合物。结论　R (- ) 布洛芬在大鼠体内发生了异构体转化 ,异丁基侧链中末端甲基的氧化代谢具有立体选择性 OBJECTIVE To study the transformation of R (-) ibuprofen metabolites and isomers in rat urine by solid phase extraction (1H-NMR) spectroscopy. Methods The urinary excretion of rats in 0 ~ 24 h after taking R (-) ibuprofen was determined by solid-phase extraction (SPE) column and the structure of metabolites was determined by 1H-NMR. Results Urine contained four major metabolites: 2’-hydroxybuprofen and its glucuronide conjugate, 1’-carboxybutamine glucuronide and ibuprofen glucuronide. The latter two are diastereomer mixtures. CONCLUSIONS: R (-) ibuprofen undergoes isomer transformation in rats, the stereoselectivity of terminal methyl oxidation in the isobutyl side chain