What Is Uric Acid?
Uric acid is an organic compound with the chemical formula C5H4N4O3, having a molecular weight of 168.11. Also known as 2,6,8-trihydroxypurine, it appears as a white to slightly light brown powder and is insoluble in water. It is excreted as a nitrogen metabolism end product in birds, reptiles, and insects, and to a lesser extent in human urine as a nucleic acid metabolism product. Initially discovered in bladder stones, uric acid’s CAS number is 69-93-2 and is not classified as hazardous according to GHS criteria.
Uses of Uric Acid
Uric acid has applications in research and pharmaceutical fields. The blood uric acid level serves as an indicator of hyperuricemia, a condition arising from the body’s difficulty in excreting uric acid or overproduction. High purine intake can also elevate this risk. Hyperuricemia is diagnosed when uric acid levels exceed 7.0 mg/dL, while levels below 2 mg/dL indicate hypouricemia, a condition of excessive uric acid excretion or underproduction.
Properties of Uric Acid
Uric acid’s melting point exceeds 300°C. It is soluble in sodium hydroxide solutions but insoluble in ethanol and ether. The murexide reaction, turning an aqueous uric acid solution reddish-purple upon adding nitric acid and ammonia, confirms its presence. Excessive accumulation leads to urate crystal formation, triggering gout attacks. While uric acid acts as an antioxidant, it can promote oxidation under certain conditions.
Types of Uric Acid
Commercially, uric acid is available in various amounts, including 10 g, 25 g, 100 g, 500 g, and 1 kg options.
Other Information About Uric Acid
1. Production Pathway in the Body
Uric acid biosynthesis involves xanthine dehydrogenase, starting from ribose-5-phosphate to xanthine. The body’s production pathways are split into exogenous (dietary purines) and endogenous (cellular metabolism of nucleic acids and ATP), contributing to approximately 20-30% and 70-80% of produced uric acid, respectively. Daily human uric acid production is about 0.6 grams.
2. Relationship to Gout
Gout, characterized by uric acid crystal deposition in joints, leads to recurrent arthritis. It commonly affects the toes, insteps, knees, and elbows, among other joints. Gouty nodules, resulting from uric acid deposits, frequently occur on fingers, hands, feet, and elbows, and can also affect kidneys and the skin beneath the ears, potentially causing urinary tract stones in patients.
3. Association With Atherosclerosis
Epidemiological studies suggest a link between high uric acid levels and increased arteriosclerosis risk. Since 2020, uric acid salt deposition in arterial walls has been documented, potentially damaging vessel cells and contributing to atherosclerosis.