title: Studies on drug metabolism by use of isotopes. XXIX--Studies of the differences in biological fates of ephedrine isomers by use of a pseudo-racemic mixture.
abstract: The differences in metabolic fates of the optical isomers of ephedrine were investigated by use of a pseudo-racemic mixture technique. In rats, the (-)-isomer was more easily p-hydroxylated than the (+)-isomer. A stereoselective reaction in the formation of the glucuronides of ephedrine, norephedrine and p-hydroxyephedrine was observed. The (-)-isomers were more easily subjected to glucuronide formation than the (+)-isomers. In human subjects, N-demethylation proved to be a stereoselective reaction. It is also suspected that oxidative dealkylation of norephedrine is a stereoselective reaction.
mesh_terms: D000818:Animals; D001711:Biotransformation; D003640:Dealkylation; D003903:Deuterium; D004809:Ephedrine / Q000031:analogs & derivatives / Q000032:analysis* / Q000378:metabolism / Q000652:urine; D006626:Hippurates / Q000652:urine; D007202:Indicators and Reagents; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D013237:Stereoisomerism
chemical_list: D006626:Hippurates; D007202:Indicators and Reagents; D003903:Deuterium; C026055:oxilofrine; D004809:Ephedrine; C030514:hippuric acid