Summary
The structures of six metabolites were elucidated using rat urine after intragastric administration of14C-thymoxamine by means of enzyme incubations, mass spectrometry and synthesis of metabolites: desacetylthymoxamine, N-demethyl-desacetylthymoxamine, the corresponding sulfates and glucuronides. The nature of the conjugates was confirmed by biosynthesis, i.e., co-administration of unlabeled thymoxamine and35S-sulfate or14C-glucose.
The system high performance liquid chromatography-radioactivity detection was used for interspecies comparison. All biotransformation pathways are seen in rat and man. In dog and cat demethylation is a very minor reaction. Glucuronidation is not observed in the cat.
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Vollmer, K.O., von Hodenberg, A. Metabolism of thymoxamine III. Structure elucidation of the metabolites and interspecies comparison. European Journal of Drug Metabolism and Pharmacokinetics 10, 139–145 (1985). https://doi.org/10.1007/BF03189708
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DOI: https://doi.org/10.1007/BF03189708