Use of high-field nulear magnetic resonance spectroscopy for the analysis of stereoselective metabolites of ibuprofen (R) -enantiomer in rat urine
Yang, C.; He, W.Y.; Kong, M.; Xu, R.M.; Zhang, S.R.; Si, Y.K.
Yao Xue Xue Bao 35(11): 843-846
2000
ISSN/ISBN: 0513-4870 PMID: 11218863 Document Number: 520117
To study the metabolic chiral inversion and chiral metabolites of R-(-)-ibuprofen. Following administration of R-(-)-ibuprofen (250 mg.kg-1), analysis was performed on rat urine purified extracts obtained by solid phase extraction onto C-18 bonded silica gel, then the metabolites of ibuprofen were detected and identified by 1HNMR spectroscopy. Except for a little ibuprofen, there were 2'-hydroxy-ibuprofen and its glucuronide, 1'-carboxy-ibuprofen glucuronide and ibuprofen glucuronide in rat urine. 2'-hydroxy-ibuprofen is the main metabolite. 1'-carboxy-ibuprofen glucuronide and ibuprofen glucuronide were diastereoisomers. There was the phenomenon of metabolic chiral inversion, whereby the R-enantiomer is transformed in vivo to its active S-antipode via an unusual process.