High-voltage electrophoretic separation of tryptophan metabolites of the kynurenine pathway.
An analytical separation method for tryptophan and its seven metabolites of the kynurenine pathway by high-voltage paper electrophoresis is presented. Anthranilic acid, 3-hydroxyanthranilic acid, kynurenic acid, kynurenine, nicotinic acid, quinolinic acid, xanthurenic acid and unmetabolized tryptophan are measured in urine. Using radioactive labelling and scintillation counting as a quantification method, the relative standard deviation varied from 3.5% to 14.4%, corresponding to kynurenine and nicotinic acid, respectively. The recovery of labelled tryptophan added to urine was 95%. An advantage of the electrophoretic method is the minor tailing of spots and, hence, a good resolution of the components. For the monovalent anions of the kynurenine pathway metabolites, a linear correlation (r = 0.9996) was found between the experimental relative electrophoretic mobility and the quantity M-2/3, where M is the molecular mass of the anion.
Department of Pharmacology and Toxicology, University of Kuopio, Finland.
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Sainio
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Hynninen
D000818:Animals; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004586:Electrophoresis; D007737:Kynurenine / Q000378:metabolism*; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains; D012997:Solvents; D013056:Spectrophotometry, Ultraviolet; D014364:Tryptophan / Q000302:isolation & purification* / Q000652:urine
D012997:Solvents; D007737:Kynurenine; D014364:Tryptophan