THE USE OF MASS SPECTROSCOPY AND ‘3C AND ‘H NUCLEAR MAGNETIC RESONANCE IN THE CHARACTERIZATION OF

The metabolism of a recently developed anticonvulsant drug. 1-methyl-(2. 6-xylyloxy)ethyla-mine (KO 1173). was investigated by a combination of gas chromatography, chemical ionization and high-resolution electron impact mass spectrometry. and proton and ‘3C nuclear magnetic resonance spectrometry. Two unknown metabolites in the urine of a patient taking the drug were trapped in milligram amounts by preparative gas chromatography. In conjunction with chemical ionization, high-resolution electron impact mass spectrometry gave unequivocal empirical formulae for the two peaks: each metabolite had the same empirical formula as the drug plus one oxygen atom. Proton and ‘3C nuclear magnetic resonance spectrometry showed that one metabolite was the free base having a hydroxyl group para to the ether linkage, and the other metabolite was the free base having one of the methyl groups replaced by a CH2OH group. The four spectroscopic techniques employed provide a powerful tool for the identification of drug metabolites. The new experimental techniques of chemical ionization mass spectrometry and Fourier trans