The excretion of N-methyl-2-pyridone-5-carboxamide by man following ingestion of several known or potential precursors.

The development of a rapid method for the determination of N-methyl2-pyridone-5-carboxamide (pyridone) in urine (1) has made it practical to attempt to confirm and extend the studies of Holman and de Lange (2) and others (3-5) concerning the excretion of the pyridone following the administration of various known or possible precursors to man. In the conversion of nicotinic acid to the pyridone it must be amidated, N’-methylated, and oxidized in the sixth position. All six possible derivatives of nicotinic acid involving these three modifications in the structure singly (6-hydroxynicotinic acid, nicotinamide, trigonelline) or in pairs (6-hydroxynicotinamide, N1-methylnicotinamide, N-methyl-2-pyridoned-carboxylic acid) have now been administered to human subjects, and the results suggest that these reactions probably occur in the order indicated. In addition, the present studies determined the relationship between the dosages of the tested compounds and the extent to which they may be accounted for by increased excretion of the pyridone in the urine.