title: Metabolism of minocycline in humans.
abstract: Metabolites of tetracycline antibiotics have not previously been isolated from human excreta. It is now demonstrated that minocycline is the first tetracycline to be metabolized in man. A two-step liquid chromatographic procedure was used to isolate three metabolites from human urine. The principal metabolite was tentatively identified as 9-hydroxyminocycline by mass spectral and spectrophotometric analysis and comparison with a synthetic compound. The latter was prepared by incubation of minocycline in a modified Udenfriend system, simulating an enzymatic oxygenase. Two other major metabolites are probably mono-N-demethylated derivatives. Substantial amounts of 4-epiminocycline, which probably resulted from minocycline epimerization rather than biotransformation, were also present.
mesh_terms: D000900:Anti-Bacterial Agents / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D005470:Fluorometry; D006801:Humans; D006868:Hydrolysis; D006900:Hydroxylation; D007536:Isomerism; D013058:Mass Spectrometry; D008911:Minocycline / Q000031:analogs & derivatives / Q000378:metabolism*; D013056:Spectrophotometry, Ultraviolet; D013754:Tetracyclines / Q000378:metabolism*
chemical_list: D000900:Anti-Bacterial Agents; D013754:Tetracyclines; D008911:Minocycline