skip to main content

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

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.
Authors:
; ;  [1]
  1. (Department of Chemistry, Seattle University, WA (USA))
Publication Date:
OSTI Identifier:
5459806
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physiological Chemistry and Physics and Medical NMR; (United States); Journal Volume: 22:2
Country of Publication:
United States
Language:
English
Subject:
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