Time dependent inhibition of xanthine oxidase in irradiated solutions of folic acid, aminopterin and methotrexate

Journal Article · Mon Jan 01 00:00:00 EST 1990 · Physiological Chemistry and Physics and Medical NMR; (United States)

OSTI ID:5459806

Robinson, K; Pilot, T F; Meany, J E ^[1]

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1. Department of Chemistry, Seattle University, WA (USA)

The xanthine oxidase catalyzed oxidation of hypoxanthine was followed by monitoring the formation of uric acid at 290 nm. Inhibition of xanthine oxidase occurs in aqueous solutions of folic acid methotrexate and aminopterin. These compounds are known to dissociate upon exposure to ultraviolet light resulting in the formation of their respective 6-formylpteridine derivatives. The relative rates of dissociation were monitored spectrophotometrically by determining the absorbance of their 2,4-dinitrophenylhydrazine derivatives at 500 nm. When aqueous solutions of folic acid, aminopterin and methotrexate were exposed to uv light, a direct correlation was observed between the concentrations of the 6-formylpteridine derivatives existing in solution and the ability of these solutions to inhibit xanthine oxidase. The relative potency of the respective photolysis products were estimated.

• OSTI ID: 5459806
• Journal Information: Physiological Chemistry and Physics and Medical NMR; (United States), Vol. 22:2; ISSN 0748-6642
• Country of Publication: United States
• Language: English

Related Subjects

63 RADIATION, THERMAL, AND OTHER ENVIRON. POLLUTANT EFFECTS ON LIVING ORGS. AND BIOL. MAT.
HYPOXANTHINE
METABOLISM
OXIDOREDUCTASES
CHEMICAL RADIATION EFFECTS
AMINOPTERIN
FOLIC ACID
METHOTREXATE
PHOTOLYSIS
SPECTROPHOTOMETRY
ULTRAVIOLET RADIATION
AMINES
AMINO ACIDS
ANTIMETABOLITES
AROMATICS
AZAARENES
CARBOXYLIC ACIDS
CHEMICAL REACTIONS
DECOMPOSITION
DRUGS
ELECTROMAGNETIC RADIATION
ENZYMES
HEMATINICS
HEMATOLOGIC AGENTS
HETEROCYCLIC COMPOUNDS
HYDROXY COMPOUNDS
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
PHOTOCHEMICAL REACTIONS
PTERIDINES
PURINES
RADIATION EFFECTS
RADIATIONS
VITAMIN B GROUP
VITAMINS
560120* - Radiation Effects on Biochemicals
Cells
& Tissue Culture