IDENTIFICATION OF QUININE METABOLITES IN URINE AFTER ORAL DOSING IN HUMANS

A gas chromatographic-mass spectrometric method was used to separate q uinine and its metabolites present in urine after oral dosing of 300 m g quinine in humans. The technique allowed the separation of quinine a nd ten metabolites. Four of these metabolites were definitely identifi ed as 3-hydroxyquinine, 2'-quinone, O-desmethylquinine and 10,11-dihyd roxy-dihydroquinine, by comparing their methane chemical ionization ma ss spectra with those of authentic standards prepared by organic synth esis. Six other metabolites are described for the first time in human urine. From their electron impact and chemical ionization mass spectra , we propose these compounds to be 3-hydroxy-2'-quinone, O-desmethyl-2 '-quinone, O-desmethyl-3-hydroxyquinine, O-desmethyl-3-hydroxy-2'-quin one, 10,11-dihydroxydihydro-2'-quinone and 10,11- dihydroxydihydro-O-d esmethylquinine. These secondary metabolites probably arose from furth er biotransformation of the four primary metabolites. (C) 1998 Elsevie r Science B.V. All rights reserved.