Isolation and Identification of Morphine N-Oxide α- and β-Dihydromorphines, β- or γ-Isomorphine, and Hydroxylated Morphine as Morphine Metabolites in Several Mammalian Species

Abstract

New morphine metabolites in the urine of guinea pigs, rats, rabbits, cats, monkeys, and humans were isolated with column chromatography, solvent extraction, and TLC and identified with TLC, GLC, and GLC–mass spectrometry. In addition to the known morphine metabolites, morphine N-oxide was isolated from the urine of guinea pigs, and α- and β-dihydromorphines were isolated or detected in the urine of guinea pigs, rats, and rabbits. Monohydroxymorphine was identified tentatively in the urine of guinea pigs, rats, rabbits, and cats. Dihy- droxymorphine was identified tentatively in the urine of guinea pigs, rats, and, possibly, rabbits. Finally, β- or γ-isomorphine was identified tentatively in the urine of guinea pigs. The newly described morphine metabolites may be involved in some long lasting pharmacological effects of morphine.