title: Stereoselective inversion of (R)-(-)-benoxaprofen to the (S)-(+)-enantiomer in humans.
abstract: The enantiomeric composition of benoxaprofen [(RS)-2-(P-chlorophenyl)-alpha-methyl-5-benzoxazoleacetic acid] in plasma and urine was determined after oral administration of both the racemic mixture and the (R)-(-)-enantiomer to normal human volunteers. Resolution of the diastereomeric amides, formed by the reaction of the enantiomers with (S)-(-)-apha-methylbenzylamine, was accomplished by gas chromatography. The (R)-(-1)-enantiomer of the parent drug was stereoselectively inverted to its (S)-(+) isomer in humans.
mesh_terms: D000328:Adult; D000893:Anti-Inflammatory Agents / Q000097:blood / Q000378:metabolism* / Q000652:urine; D001583:Benzoxazoles / Q000097:blood / Q000378:metabolism* / Q000652:urine; D001711:Biotransformation; D006801:Humans; D008297:Male; D008875:Middle Aged; D011422:Propionates; D013237:Stereoisomerism; D013997:Time Factors
chemical_list: D000893:Anti-Inflammatory Agents; D001583:Benzoxazoles; D011422:Propionates; C011677:benoxaprofen