Quantitative determination of tryptophan metabolites (via kynurenine) in biologic fluids.

HE POSSIBILITY OF 1)ETERMINING QUANTITATIVF LY some products of tryptophan metabolism (1) has been examined previously by one of the authors. Paper chromatography was used as a tool for the separation of kynurenine, 3-hydroxykynurenine, anthranilic, 3-hydroxyanthranilic, kynurenic, and xanthurenic acids. The purpose of this paper is to report on the quantitative determination of these products of tryptophan metabolism, and on the application of the method to biologic liquids, namely urine, l)lOod and spinal fluid, and of considering additional tryptophan metaholites, such as N2-acetylkynnrenine and xaiithurenic acid 8-methyl ether. Many papers have been published previously oil this subject, since the problem of tryptophan metabolism is of great interest, and hears close relationships with many aspects of human pathologic conditions: hemohiastotic diseases (2) (leukemias), metastatic carcinoid (3), bladder cancer (4, ri), diabetes (6, 7), cataract (8), scleroderma (9), mental (10, ii, 12) and nervous (13) diseases. Consequently, a routine quantitative cletermmation of the metabolites becomes increasingly important. Dalgliesh (14) obtained the separation of the aromatic metaholites of tryptophan by absorbing them from the urine with deactivated charcoal and eluting them with aqueous phenol. The eluate was concentrated and then chromatographed on paper l)y the two-dimensional descending technic. This method made possible the separation