metabolism of n-methylformamide to urinary methylamine , urinary n-acetyl-s- ( n-methylcarbamoyl ) -cysteine and biliary s- ( n-methylcarbamoyl ) glutathione was found to be subject to large intermolecular primary kinetic isotope effects when hydrogen was replaced by deuterium in the formyl group ( kh/kd = 5.5 +/- 0.2 , 4.5 +/- 1.0 and 7 +/- 2 , respectively ) , as shown by mass spectrometry of derivatives of these metabolites .
C0020275
hydrogen
C0011744
deuterium