Uric acid
General
Systematic name	7,9-dihydro-1H-purine- 2,6,8(3H)-trione
Other names	2,6,8 Trioxypurine
Molecular formula	C5H4N4O3
SMILES	C12NC(=O)NC(=O)C=2NC(=O)N1
Molar mass	168g/mol
Appearance	White Crystals
CAS number	69-93-2
Properties
Density and phase	1.87
Solubility in water	Slightly
Melting point	decomposes on heating
Boiling point	N/A
Acidity (pKa)	3.89
Structure
Molecular shape	?
Coordination geometry	?
Crystal structure	?
Dipole moment	?
Hazards
MSDS	?
Main hazards	?
Flash point	? °C
R/S statement	R: ? S: ?
RTECS number	?
Supplementary data page
Structure & properties	?
Thermodynamic data	Phase behaviour Solid, liquid, gas
Spectral data	UV, IR, NMR, MS
Related compounds
Related compounds	hypoxanthine, xanthine, purine, urea, urate, ammonia
Except where noted otherwise, data are given for materials in their standard state (at 25°C, 100 kPa) Infobox disclaimer and references

Uric acid (or urate) is an organic compound of carbon, nitrogen, oxygen and hydrogen with the formula C₅H₄N₄O₃. Image File history File links File links The following pages link to this file: Uric acid ... Image File history File links File links The following pages link to this file: Uric acid ... IUPAC nomenclature is a system of naming chemical compounds and of describing the science of chemistry in general. ... This article or section does not cite any references or sources. ... The simplified molecular input line entry specification or SMILES is a specification for unambiguously describing the structure of chemical molecules using short ASCII strings. ... Molar mass is the mass of one mole of a chemical element or chemical compound. ... CAS registry numbers are unique numerical identifiers for chemical compounds, polymers, biological sequences, mixtures and alloys. ... In physics, density is mass m per unit volume V. For the common case of a homogeneous substance, it is expressed as: where, in SI units: ρ (rho) is the density of the substance, measured in kg·m-3 m is the mass of the substance, measured in kg V is... In the physical sciences, a phase is a set of states of a macroscopic physical system that have relatively uniform chemical composition and physical properties (i. ... It has been suggested that this article or section be merged with Solution. ... This article describes water from a scientific and technical perspective. ... The melting point of a crystalline solid is the temperature at which it changes state from solid to liquid. ... The boiling point of a substance is the temperature at which it can change its state from a liquid to a gas throughout the bulk of the liquid at a given pressure. ... The acid dissociation constant (Ka), also known as the acidity constant or the acid-ionization constant, is a specific equilibrium constant for the reaction of an acid with its conjugate base in aqueous solution [1]. // When an acid dissolves in water, it partly dissociates forming hydronium ions and its conjugate... four sp³ orbitals three sp² orbitals In chemistry, hybridisation or hybridization (see also spelling differences) is the concept of mixing atomic orbitals to form new hybrid orbitals suitable for the qualitative description of atomic bonding properties. ... The coordination geometry of an atom is the geometrical pattern formed by its neighbors in a molecule or a crystal. ... Enargite crystals In mineralogy and crystallography, a crystal structure is a unique arrangement of atoms in a crystal. ... The Earths magnetic field, which is approximately a dipole. ... An example MSDS in a US format provides guidance for handling a hazardous substance and information on its composition and properties. ... The examples and perspective in this article or section may not represent a worldwide view. ... The flash point of a flammable liquid is the lowest temperature at which it can form an ignitable mixture with air. ... Risk and Safety Statements, also known as R/S statements, R/S numbers, R/S phrases, and R/S sentences, is a system of hazard codes and phrases for labeling dangerous chemicals and compounds. ... RTECS, also known as Registry of Toxic Effects of Chemical Substances, is a database of toxicity information compiled from the open scientific literature that is available for charge. ... Ultraviolet-Visible Spectroscopy or Ultraviolet-Visible Spectrophotometry (UV/ VIS) involves the spectroscopy of photons (spectrophotometry). ... Infrared spectroscopy (IR Spectroscopy) is the subset of spectroscopy that deals with the IR region of the EM spectrum. ... It has been suggested that NMR Data Processing be merged into this article or section. ... Mass spectrometry (also known as mass spectroscopy (deprecated)[1] or informally, mass-spec and MS) is an analytical technique used to measure the mass-to-charge ratio of ions. ... Hypoxanthine is a naturally occurring purine derivative, and one of the products of the action of xanthine oxidase on xanthine, though more normally in purine degradation, hypoxanthine is oxidized by xanthine oxidase to form xanthine. ... Xanthines are a group of alkaloids that are commonly used for their effects as mild stimulants and as bronchodilators, notably in treating the symptoms of asthma. ... Purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. ... Urea is an organic compound of carbon, nitrogen, oxygen and hydrogen, with the formula CON2H4 or (NH2)2CO. Urea is also known as carbamide, especially in the recommended International Nonproprietary Names (rINN) in use in Europe. ... Uric Acid Uric acid is an organic compound of carbon, nitrogen, oxygen and hydrogen, with the formula C5H4N4O3 It is a minor end-product of nitrogen metabolism in the human body (the main product being urea), and is found in small amounts in urine. ... Ammonia is a compound with the formula NH3. ... In chemistry, the standard state of a material is its state at 1 bar (100 kilopascals) and 25 degrees Celsius (298. ... Benzene is the simplest of the arenes, a family of organic compounds An organic compound is any member of a large class of chemical compounds whose molecules contain carbon and hydrogen; therefore, carbides, carbonates, carbon oxides and elementary carbon are not organic (see below for more on the definition controversy... General Name, Symbol, Number carbon, C, 6 Chemical series nonmetals Group, Period, Block 14, 2, p Appearance black (graphite) colorless (diamond) Standard atomic weight 12. ... General Name, Symbol, Number nitrogen, N, 7 Chemical series nonmetals Group, Period, Block 15, 2, p Appearance colorless gas Standard atomic weight 14. ... General Name, Symbol, Number oxygen, O, 8 Chemical series nonmetals, chalcogens Group, Period, Block 16, 2, p Appearance colorless (gas) very pale blue (liquid) Standard atomic weight 15. ... General Name, Symbol, Number hydrogen, H, 1 Chemical series nonmetals Group, Period, Block 1, 1, s Appearance colorless Atomic mass 1. ...

Metabolic processes

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.^[1] The loss of uricase in higher primates parallels the similar loss of the ability to synthesize ascorbic acid.^[2] This may be because in higher primates uric acid (urate) partially replaces ascorbic acid.^[3] Both urate and ascorbate are strong reducing substances (electron donors) and potent antioxidants. In humans, about half the antioxidant capacity of plasma comes from uric acid. Xanthine Oxidase The enzyme xanthine oxidase, or XO, (bovine milk enzyme is PDB 1FIQ, EC 1. ... Xanthines are a group of alkaloids that are commonly used for their effects as mild stimulants and as bronchodilators, notably in treating the symptoms of asthma. ... Hypoxanthine is a naturally occurring purine derivative, and one of the products of the action of xanthine oxidase on xanthine, though more normally in purine degradation, hypoxanthine is oxidized by xanthine oxidase to form xanthine. ... Many organisms have metabolic pathways to synthesise and break down purines. ... The enzyme urate oxidase, or UO, (Aspergillus flavus enzyme PDB 1R4U, EC 1. ... Allantoin is a botanical extract of the comfrey plant and is used for its healing, soothing, and anti-irritating properties. ... For other uses, see Vitamin C (disambiguation). ... Space-filling model of the antioxidant metabolite glutathione. ...

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. While this compound is produced through a complex and energetically costly metabolic pathway (in comparison to other nitrogenated wastes such as urea or ammonia), its elimination minimizes water loss. It is therefore commonly found in the excretions of animals that live in very dry environments like the kangaroo rat. The Dalmatian dog has a defect in uric acid metabolism resulting in decreased conversion to allantoin so this breed excretes uric acid, and not allantoin, in the urine. Anabolism is the aspect of metabolism that contributes to growth. ... “Aves” redirects here. ... Subclasses Anapsida Diapsida Synonyms Reptilia Laurenti, 1768 Reptiles are tetrapods and amniotes, animals whose embryos are surrounded by an amniotic membrane, and members of the class Sauropsida. ... Feces, faeces, or fæces (see spelling differences) In humans, defecation may occur (depending on the individual and the circumstances) from once every two or three days to several times a day. ... In biochemistry, a metabolic pathway is a series of chemical reactions occurring within a cell. ... Urea is an organic compound of carbon, nitrogen, oxygen and hydrogen, with the formula CON2H4 or (NH2)2CO. Urea is also known as carbamide, especially in the recommended International Nonproprietary Names (rINN) in use in Europe. ... Ammonia is a compound with the formula NH3. ... Impact from a water drop causes an upward rebound jet surrounded by circular capillary waves. ... Allantoin is a botanical extract of the comfrey plant and is used for its healing, soothing, and anti-irritating properties. ...

Medical issues

Humans produce only small quantities of uric acid. In human blood, uric acid concentrations between 3.6 mg/dL (~214µmol/L) and 8.3 mg/dL (~494µmol/L) (1mg/dL=59.48 µmol/L)^[4] are considered normal by the American Medical Association, although significantly lower levels are common in vegetarians due to a decreased intake of purine-rich meat.^[5] Human blood smear: a - erythrocytes; b - neutrophil; c - eosinophil; d - lymphocyte. ... The American Medical Association (AMA) is the largest association of medical doctors in the United States. ... For animals adapted to eat primarily plants, sometimes referred to as vegetarian animals, see Herbivore. ... Purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. ...

High Uric Acid

Gout

Excess serum accumulation of uric acid can lead to a type of arthritis known as gout.^[6] Arthritis (from Greek arthro-, joint + -itis, inflammation; plural: arthritides) is a group of conditions where there is damage caused to the joints of the body. ...

Elevated (serum uric acid) level (hyperuricemia) can result from high intake of purine-rich foods, high fructose intake (regardless of fructose's low Glycemic Index (GI) value) 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. Hyperuricemia is the presence of high levels of uric acid in the blood. ... Fructose (or levulose) is a simple sugar (monosaccharide) found in many foods and is one of the three most important blood sugars along with glucose and galactose. ... Kidney stones, or Renal calculi, are solid concretions (crystal aggregations) of dissolved minerals in urine; calculi typically form inside the kidneys or ureters. ... Kidney stones are solid accretions (crystals) of dissolved minerals in urine found inside the kidneys or ureters. ...

Gout can occur where serum uric acid levels are as low as 6 mg/dL (~357µmol/L), but an individual can have serum values as high as 9.5 mg/dL (~565µmol/L) and not have gout^[7] (no abstract available; levels reported at^[8]).

Lesch-Nyhan syndrome

Lesch-Nyhan syndrome is also associated with very high serum uric acid levels.^[9]-1...

Spasticity, involuntary movement and cognitive retardation as well as manifestations of gout are seen in cases of this syndrome.^[10]

Cardiovascular disease

Although uric acid can act as an antioxidant, excess serum accumulation is implicated in cardiovascular disease^[11] Cardiovascular disease refers to the class of diseases that involve the heart and/or blood vessels (arteries and veins). ...

Low Uric Acid

Multiple sclerosis

Lower serum values of uric acid have been associated with Multiple Sclerosis.^[12] Multiple sclerosis (MS) patients have been found to have serum levels ~194µmol/L, with patients in relapse averaging ~160µmol/L and patients in remission averaging ~230µmol/L. Serum uric acid in healthy controls was ~290µmol/L.^[13] (1mg/dL=59.48 µmol/L)^[14]

A 1998 study completed a statistical analysis of 20 million patient records, comparing serum uric acid values in patients with gout and patients with multiple sclerosis. Almost no overlap between the groups was found.^[15]

Uric acid has been successfully used in the treatment and prevention of the animal (murine) model of MS. A 2006 study found that elevation of serum uric acid values in multiple sclerosis patients, by oral supplementation with inosine, resulted in lower relapse rates, and no adverse effects.^[16] Inosine is a molecule (known as a nucleoside) that is formed when hypoxanthine is attached to a ribose ring (also known as a ribofuranose) via a β-N9-glycosidic bond. ...

Oxidative Stress

Uric acid may be a marker of oxidative stress,^[17] and may have a potential therapeutic role as an antioxidant (PMID 16375736). On the other hand, like other strong reducing substances such as ascorbate, uric acid can also act as a peroxidant,^[18] particularly at elevated levels. Thus, it is unclear whether elevated levels of uric acid in diseases associated with oxidative stress such as stroke and atherosclerosis are a protective response or a primary cause.^[19] Oxidative stress is a medical term for damage to animal or plant cells (and thereby the organs and tissues composed of those cells) caused by reactive oxygen species, which include (but are not limited to) superoxide, singlet oxygen, peroxynitrite or hydrogen peroxide. ... Space-filling model of the antioxidant metabolite glutathione. ... Stroke (or cerebrovascular accident or CVA) is the clinical designation for a rapidly developing loss of brain function due to an interruption in the blood supply to all or part of the brain. ...

For example, some researchers propose that hyperuricemia-induced oxidative stress is a cause of Metabolic syndrome.^[20][21] On the other hand, plasma uric acid levels correlate with longevity in primates and other mammals.^[22] This is presumably a function of urate's antioxidant properties. Metabolic syndrome is a combination of medical disorders that increase ones risk for cardiovascular disease and diabetes. ...

Sources of uric acid

In many instances, people have a high incidence of uric acid for hereditary reasons.

Diet may also be a factor.

Purines are found in high amounts in animal food products, especially internal organs.^[23]

Examples of high purine sources include: sweetbreads, anchovies, sardines, liver, beef kidneys, brains, meat extracts (e.g Oxo, Bovril), herring, mackerel, scallops, game meats, and gravy.

A moderate amount of purine is also contained in beef, pork, poultry, fish and seafood, asparagus, cauliflower, spinach, mushrooms, green peas, lentils, dried peas, beans, oatmeal, wheat bran and wheat germ.^[24]

Moderate intake of purine-containing food is not associated with an increased risk of gout.^[25]

Serum uric acid can be elevated due to high fructose intake, reduced excretion by the kidneys, and or high intake of dietary purine. Fructose (or levulose) is a simple sugar (monosaccharide) found in many foods and is one of the three most important blood sugars along with glucose and galactose. ...

Fructose can be found in processed foods and soda beverages - in some countries, in the form of high fructose corn syrup. High fructose corn syrup (HFCS) refers to a group of corn syrups which have undergone enzymatic processing in order to increase their fructose content and are then mixed with pure corn syrup (100% glucose) to reach their final form. ...

Causes of low uric acid

Aside from avoidance of purine foods, both accumulated copper and low vitamin B2 can exacerbate low uric acid levels, which in turn is hypothesized to lead to myelin degeneration seen in Multiple Sclerosis.^[26]

Other uric acid facts

The high nitrogen content of uric acid makes guano a useful agricultural fertilizer. The Chincha guano islands in Peru. ... Spreading manure, an organic fertilizer Fertilizers (also spelled fertilisers) are compounds given to plants to promote growth; they are usually applied either via the soil, for uptake by plant roots, or by foliar feeding, for uptake through leaves. ...

The crystalline form of uric acid is used as a reflector in certain species of fireflies. Genera Curtos Cyphonocerus Drilaster Ellychnia Hotaria Lampyris Lucidina Lucidota Luciola - Japanese fireflies Phausis Photinus - common eastern firefly Photuris Pristolycus Pyractomena Pyrocoelia Stenocladius many others Wikispecies has information related to: Lampyridae Lampyridae is a family in the beetle order Coleoptera, members of which are commonly called fireflies, lightning bugs, or glow...

See also

• Hyperuricemia

Hyperuricemia is the presence of high levels of uric acid in the blood. ...

External links

• MedlinePlus - Uric Acid Test
• International Kidney Stone Institute
• Purine content in food
• Computational Chemistry Wiki