Xanthine

Xanthine is a purine base formed during purine breakdown and oxidized by xanthine oxidoreductase to uric acid.

Purine catabolism: The biochemical breakdown of purine nucleotides into smaller molecules, including uric acid in humans. Xanthine is an intermediate in the pathway that degrades purines.
Purine: A nitrogen-containing bicyclic aromatic compound that forms the structural basis of purine nucleobases. Xanthine is a substituted member of the purine chemical family.
Xanthinuria: A rare metabolic disorder in which impaired xanthine oxidoreductase activity causes excess xanthine and low uric acid. This disorder reveals the consequences of failing to oxidize xanthine.
Reactive oxygen species: Chemically reactive oxygen-containing molecules produced in cells and during metabolic reactions. Xanthine oxidoreductase can generate reactive oxygen species while oxidizing xanthine.
Hypoxanthine: A purine base formed during nucleotide breakdown and oxidized to xanthine by xanthine oxidoreductase. Its oxidation is the step immediately before xanthine formation.
Purine nucleoside phosphorylase: An enzyme that cleaves purine nucleosides into a base and ribose-1-phosphate. Its reactions help generate bases that feed into xanthine-producing pathways.
Gout: An inflammatory arthritis caused by deposition of monosodium urate crystals in joints and tissues. Treatments that alter xanthine oxidation can lower uric acid and reduce gout risk.
Xanthine dehydrogenase: A form of xanthine oxidoreductase that primarily transfers electrons to NAD+ rather than oxygen. Its electron acceptor differs from the oxidase form, changing reactive oxygen production.
Xanthine oxidoreductase: An enzyme system that oxidizes hypoxanthine to xanthine and xanthine to uric acid. It catalyzes both reactions involving xanthine in purine degradation.
Nucleotide: A molecule composed of a nitrogenous base, a sugar, and one or more phosphate groups. Nucleotide breakdown supplies the purine bases from which xanthine forms.

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