Pterins, Unconjugated

W. Lovenberg and R. A. Levine, Eds. Unconjugated Pterins in Neurobiology Basic and Clinical Aspects , Taylor Francis, London, 1987. 

B-87M1 718-03 H. C. Curtius, N. Blau and R. A. Levine Unconjugated Pterins and Related Biogenic... 

Subsequent studies by the same group (W7) have shown that the increased endogenous fluorescence in patients with chronic renal failure is due to the unconjugated pteridine, xanthopterin (2-amino-4,6-pteridinedione, 179 Da see Table 4 and Figs. 10 and 11) (B23, Dll, L15, Pll). Unlike the conjugated pteridines (folates), the function of many of the unconjugated pteridines (pterins) has yet to be elucidated (U2, Z3). So far only biopterin has been shown to have a defined role, being a cofactor in the hydroxylation of several aromatic amino acids involved in the formation of neuronal hormones such as catecholamines and serotonin. 

Stea, B., Halpem, R. M., Halpern, B. C., and Smith, R. A., Urinary excretion levels in unconjugated pterins in cancer patients and normal individuals. Clin. Chim. Acta 113,231-242 (1981). 

Roethler, F., and Karobath, M. Quantitative Determination of Unconjugated Pterins in Urine by Gas Chromatography/Mass Spectrometry... 

Pterinoid investigations have steadily extended knowledge of (1) transfer of Cx groups (2) biosynthetic and functional connections between folic vitamins and other nitrogenous heterocycles—purines, thymine (or thymidine), riboflavin, vitamins Be and Bi, and unconjugated pterins. 

More knowledge of pterinoids means renewed hope of solving such old clinical problems as the pathogenesis of sprue. Increased interest, too, attaches to the unconjugated pterins in the body Are they increased or diminished in some diseases The effectiveness of antifolics in the palliative treatment of leukemia is halted by toxic symptoms and, eventually, by drug fastness this emphasizes the need to explore pteridine metabolism to find new opportunities for chemotherapy aimed at pterinoid targets. 

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