Xanthine OxidaseXanthineXanthine DehydrogenaseXanthinesAllopurinolOxypurinolMolybdenumHypoxanthineHypoxanthinesAldehyde OxidasePteridinesUric AcidKetone OxidoreductasesMolecular StructureMilkFree RadicalsPurinesSuperoxidesStructure-Activity RelationshipTungstenOxidation-ReductionKineticsHydroxidesElectron Spin Resonance SpectroscopySuperoxide DismutaseCattleMagnetic Resonance SpectroscopyCoenzymesTungsten CompoundsHydroxyl RadicalMetalloproteinsFlavin-Adenine DinucleotideChromatography, High Pressure LiquidTheobromineEnzyme InhibitorsChemistryChemical PhenomenaFree Radical ScavengersHydrogen PeroxideReactive Oxygen SpeciesUrate OxidaseOxygenIndicators and ReagentsSpectrophotometry, UltravioletStereoisomerismMolecular Sequence DataDithioniteDose-Response Relationship, DrugLiverNADSpectrophotometryCatalaseBinding SitesHematoporphyrin DerivativeAdenosineEscherichia coliNucleobase Transport ProteinsHydrogen-Ion ConcentrationPterinsAntioxidantsCyclic N-OxidesSubstrate SpecificityGuanine DeaminaseTheophyllineHematoporphyrinsAmino Acid SequenceNitric OxidePentosyltransferasesAldehyde OxidoreductasesReceptors, PurinergicInosineOxidative StressChromatography, Thin LayerMolecular ConformationCells, CulturedBenzaldehydesFlavinsPurine-Pyrimidine Metabolism, Inborn ErrorsModels, ChemicalOxidoreductasesInhibitory Concentration 50Cell LineSulfurModels, MolecularMutationNADPH OxidaseCatalysisRats, Sprague-DawleyAllantoinGuinea PigsBase SequenceXanthopterinRats, WistarRabbitsGuanineProtein BindingSpectrophotometry, InfraredTime FactorsSpectrum AnalysisBiotransformation