Conversion of monomethyl-l-tryptophan to niacin and N1-methylnicotinamide by the rat.

Gordon and Jackson (1) found that synthetic monomethyltryptophan was capable of stimulating growth in rats subsisting on a diet deficient in tryptophan. Chin (2) isolated kynurenine and kynurenic acid from the urine of rabbits after the parenteral administration of monomethylL-tryptophan (MMT). On the other hand, recent studies have shown that the albino rat, pig, horse, cotton-rat, and man can convert dietary tryptophan to niacin or its methylated derivative, W-methyhricotinamide (W-Me) (3). In the present paper the urinary excretion of niacin and W-Me by rats after the ingestion of MMT was studied.