Chemical Properties
Uric acid, (C5H4O3N4) is a white solid, insoluble in cold water, alcohol or ether, sparingly soluble in hot water. Uric acid is a weak dibasic acid thus forming two series of salts, most of which are very slightly soluble in water (lithium urate soluble).
Occurrence
Uric acid is found in the urine, blood, and muscle juices of carnivorous animals (herbivorous animals secrete hippuric acid), in the excrement of birds, serpents and insects, and is an oxidation product of the complex nitrogenous compounds of the animal organism.
Uses
Uric Acid is a heterocyclcic compound that is created when purine nucleotides are broken down of by the human body. High blood concetration of Uric Acid is known as hyperuricemia and is often associated with a wide range of disorders and medical conditions such as gout, diabetes and metabolic syndrome. Uric acid may be a marker of oxidative stress and may have a potential therapeutic role as an antioxidant.
Definition
A nitrogen compound
produced from purines. In certain animals
(e.g. birds and reptiles), it is the main excretory product resulting from breakdown
of amino acids. In humans, uric acid crystals in the joints are the cause of gout.
Definition
uric acid: The end product of purinebreakdown in most primates, birds,terrestrial reptiles, and insects andalso (except in primates) the majorform in which metabolic nitrogen isexcreted. Being fairly insoluble, uricacid can be expelled in solid form,which conserves valuable water inarid environments. The accumulationof uric acid in the synovial ?uidof joints causes gout.
Biochem/physiol Actions
Uric acid is an insoluble catabolite produced by adenine and guanine metabolism. Accumulation of uric acid leads to gout, hyperuricemia, arthritis and renal failure. Elevated uric acid levels contributes to hypertension and pathogenesis of cardiovascular disease. Low uric acid levels associated with Parkinson′s disease and multiple sclerosis, may elicit protective functionality. High levels of uric acid in patients with chronic obstructive pulmonary disease (COPD) may serve as potential marker for diagnosis.
Purification Methods
Crystallise uric acid from hot distilled H2O (the solubility in H2O is 1part/39,000parts at 18o and 1part/2,000parts at 100o). It is best purified by dissolving in an alkaline solution and acidifying with dilute HCl and drying it at 100o in a vacuum. [Bergmann & Dikstein J Am Chem Soc 77 691 1955, Lister Purines Part II, Fused Pyrimidines Brown Ed, Wiley-Interscience pp256-257 1971, ISBN 0-471-38205-1, Beilstein 26 H 513, 26 I 151, 26 II 293, 26 III/IV 2619.]
