Uric acid (Molecule of the Month for June 2007)
Uric acid is a small organic compound which is produced by the breakdown of protein during digestion, is excreted by reptiles and birds. Xanthine oxidase oxidizes oxypurines such as xanthine and hypoxanthine to uric acid. In humans and higher primates, uric acid is the final oxidation product of purine catabolism. In most other mammals, the enzyme uricase further oxidizes uric acid to allantoin. Uric acid is also the end product of nitrogen catabolism in birds and reptiles. In such species, it is excreted in feces as a dry mass.
Humans produce only small quantities of uric acid, it is a strong reducing substance (electron donors) and potent antioxidant. In humans, about half the antioxidant capacity of plasma comes from uric acid.
Excess serum accumulation of uric acid can lead to a type of arthritis known as gout. Hyperuricemia, from the elevated level of serum uric acid can result from high intake of purine-rich foods, high fructose intake and/or impaired excretion by the kidneys. Saturation levels of uric acid in blood may result in one form of kidney stones when the urate crystallizes in the kidney. Some patients with gout eventually get uric kidney stones.
Formal Chemical Name (IUPAC)
Update by Karl Harrison
(Molecule of the Month for June 2007 )