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Updated: Aug 12, 2026

Biochemical Measurement of Neonatal Hypoxia
Published on: August 24, 2011
Pteridines as inhibitors of xanthine oxidase: structural requirements
1Medical Chemical Institute and Pregl Laboratory, Karl-Franzens-University Graz, Harrachgasse 21/II, A-8010, Graz, Austria.karl.oettl@kfunigraz.ac.at
Abstract:
Different pteridine derivatives were investigated for their inhibitory action on xanthine oxidase. From 27 investigated compounds, 13 showed concentration-dependent inhibition of the enzyme. Concentrations necessary for 50% inhibition ranged from <0.1 up to >100 microM. Different types of inhibition were found concerning xanthine and pterin as substrates: competitive, noncompetitive and mixed type. Out of 18 aromatic compounds tested, 12 were inhibitors. Only one out of nine reduced derivatives served as inhibitor. A simple regression model was used to specify the structural requirements for a pteridine to be an inhibitor. The most characteristic features of an inhibitor are aromaticity and no substitution at position 7 of the pteridine ring.
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