Tryptophan metabolites analysis

In the same year paper chromatography was first attempted by Benassi (B4) for the simultaneous analysis of 8 tryptophan metabolites (kyn-urenine, 3-hydroxykynurenine, kynurenic acid, xanthurenic acid, anthra-nilic acid, 3-hydroxyanthranilic acid, 2-aminoacetophenone, and 2-amino-3-hydroxyacetophenone), separated by means of a mixtiue of methanol, n-butanol, benzene, and water and revealed through the fluorescence in ultraviolet light of 3655 A. Each compound elicits a different fluorescent color (cf. Table 1). 

The administration of large doses of pyridoxine (100 mg per day for 30 days) did not change significantly the sum of metabolites excreted by 3 chronie schizophrenic patients after a second load of tryptophan. Only the excretion of 3-hydroxykynurenine is lowered to almost normal levels (B6). Moreover, after a challenging dose of L-tryptophan, chromatographic analysis of the serum of two schizophrenics and one control subject shows that only kynurenine is detectable in blood samples drawn at different intervals of time. 

Paper chromatographic analysis indicated that the abnormal excretion of xanthurenic acid always corresponded with higher amounts of other tryptophan metabolites such as kynurenine, acetylkynurenine, 3-hydroxy-kynurenine, and kynurenic and 3-hydroxyanthranilic acids after the usual load of tryptophan. 

Analysis of nicotinic acid, nicotinamide, and its metabolites in biological materials, i.e., blood, plasma, urine, and tissues, is important in studies on biochemical pathways (Hengen and deVries, 1985). Finder et al. (1971) described several paper and thin-layer chromatographic systems useful for the differentiation of nucleotides in tissues derived from nicotinamide and nicotinic acid. Hengen and deVries (1985) provided a table summarizing the Rp values of nicotinic acid, nicotinamide, and various intermediates of NAD+ and NADP-I- synthesis for both paper and thin-layer chromatography. Haworth and Walmsley (1972) used two-dimensional TLC on silica gel for the identification of tryptophan metabolites in urine and resolved 32 compounds including nicotinic acid and nicotinamide. Kala et al. (1978) used silica gel TLC to examine urine for nicotinic acid and its metabolites after administration of nicotinyl alcohol. They... 

The analysis of amino acids involves chromatographic issues similar to those encountered in analysis of simple amines. Underivatized amino acids have, with a few exceptions, weak UV absorbance and a strong tendency to interact with stationary phases in undesirable ways. Underivatized amino acids are normally separated with ion exchange chromatography, then visualized post-column by reaction with ninhydrin, o-phthaladehyde (OPA), or other agents. Underivatized tryptophan and the metabolites kynurenine, 3-hydroxykynurenine, kynurenic acid, and 3-hydroxyanthranilic acid, were separated on a Partisphere 5-p ODS column with fluorescent detection.121... 

Tryptophan and Zinc Absorption Boses of 4 mg Zn and 2 mg Cu were given in Trutol to subjects consuming a diet in which tryptophan was the limiting amino acid Absorption of Zn and Cu was also measured when they received the same diet plus a picolinic acid supplement Ficolinic acid is a metabolite of tryptophan which is thought to enhance zinc absorption (17) Picolonic acid was not present in the isotope dose The diets contained 0 8-l 2 mg Cu/day and 2 7-3 6 mg Zn/day (by analysis) Total tryptophan content of the diet was approximately 250 mg/day (calculated) Ficolinic acid supplementation was at a level of 10 mg/day ... 

Metabolic modifications in the chain of reactions involved in tryptophan metabolism were studied by Quagliariello et al. (Q2, Q3) and Piazza and Tancredi (P5) by qualitative analysis of urinary metabolites in 24 patients with viral hepatitis in an acute stage and in 34 subjects at least 2 months after recovery in comparison with normal controls. 

As with the other B vitamins that act as coenzymes biochemical assessment of vitamin Bg can, be made by direct chemical analysis of the vitamer or its metabolites, or by functional means. Measurements that have been used are PLP in plasma or red cells, its metabolite 4 PA in urine or plasma, the activity and activation coefficient of the red cell aminotransferases (aspartate and alanine), and the tryptophan load metabolite excretion test. As no single marker adequately reflects status, a combination of these markers olfers the best approach. 

Ions monitored in GC-SIM analysis of endogenous and metabolite trytophan and lAA in metabolic studies using 2O. [ N,] indole and [ HjJ tryptophan [112-115]. Tryptophan analysed as its A -acetyl methyl ester [116J and... 

P7. Price, J. M., Brown, R. R., and Yess, N., Testing the functional capacity of the tryptophan-niadn pathway in man by analysis of urinary metabolites. Advan. Metab. Disord. 2, 159-225 (1965). 

With the rapid advancement of microbore and reverse phase technology m HPLC, the escalating popularity of this analytical technique is not unexpected. Generally, in HPLC no cleanup procedure is necessary for biological samples. Some of the ammo acids can be analyzed directly without prior derivatization, as is the case with tyrosine, tryptophan, and their metabolites. However, the use of fluorogenic derivatization reagents is a common practice. The ammo group is the only one that requires chemical modification prior to analysis... 

H. Yoshida, I. Morita, T. Masujima and H. Imai, Direct Enrichment of Tryptophan and its Metabolites in Plasma onto a Precolumn followed by KPLC Analysis, Chem. Pharm. Bull. 30 3827 (1982). 

Joseph, M. H., Baker, H. F., and Ridley, R. M., 1981, Analysis of CSF amine metabolites and precursors including tryptophan, 5-HIAA and HVA by HPLC using fluorescence and electrochemical detection in primates effect of probenecid, in Central Neurotransmitter Turnover C. Pycockand P. V. Taberner, eds.), pp. 162-167, Groom-Helm, London. 

Gas Chromatographic Analysis of the Metabolites in the Tryptophan-Niacin Cycle. Part I. 

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