Alpha-ketoglutaric acid

Alpha-ketoglutaric acid

ImageFile = Alpha-ketoglutaric_acid.png ImageSize = 150px
IUPACName = 2-Oxopentanedioic acid
OtherNames = 2-Ketoglutaric acid
alpha-Ketoglutaric acid
2-Oxoglutaric acid
Oxoglutaric acid
Section1 = Chembox Identifiers
CASNo = 328-50-7
PubChem = 51
MeSHName = alpha-ketoglutaric+acid

Section2 = Chembox Properties
Formula = C5H6O5
MolarMass = {mol_mass|146.11} g/mol
Appearance =
Density =
MeltingPt = 113.5
BoilingPt =

Section3 = Chembox Hazards
Solubility =
MainHazards =
FlashPt =
Autoignition =

Alpha-ketoglutaric acid is one of two ketone derivatives of glutaric acid. (The term "ketoglutaric acid," when not further qualified, almost always refers to the alpha variant. Beta-ketoglutaric acid varies only by the position of the ketone functional group, and is much less common.)

Its anion, Alpha-ketoglutarate (also called oxo-glutarate) is an important biological compound. It is the keto acid produced by de-amination of glutamate, and is an intermediate in the Krebs cycle.


Krebs cycle

It is a key intermediate in the Krebs cycle, coming after isocitrate and before succinyl CoA. Anaplerotic reactions can replenish the cycle at this juncture by synthesizing alpha-ketoglutarate from transamination of glutamate, or through action of glutamate dehydrogenase on glutamate.

Formation of amino acids

Glutamine is synthesized from glutamate by glutamine synthase, which utilizes an ATP to form glutamyl phosphate; this intermediate is attacked by ammonia as a nucleophile giving glutamine and inorganic phosphate.

Nitrogen transporter

Another function is to combine with nitrogen released in the cell, therefore preventing nitrogen overload.

Alpha-ketoglutarate is one of the most important nitrogen transporter in metabolic pathways. The amino groups of amino acids are attached to it by transamination and carried to the liver where the urea cycle takes place.

Alpha-ketoglutarate is transaminated, along with glutamine, to form the excitatory neurotransmitter glutamate. Glutamate can then be decarboxylated (requiring vitamin B6) into the inhibitory neurotransmitter GABA.

It is reported that high ammonia and/or high nitrogen levels may occur with high protein intake, excessive aluminum exposure, Reye's syndrome, cirrhosis, and urea cycle disorder.

Relationship to molecular oxygen

Acting as a co-substrate, it also plays important function in oxidation reactions involving molecular oxygen.

Molecular oxygen (O2) directly oxidizes many compounds to produce useful products in an organism, such as antibiotics, etc., in reactions catalyzed by oxygenases. In many oxygenases, alpha-ketoglutarate helps the reaction by being oxidized together with the main substrate. In fact, one of the alpha-ketoglutarate-dependent oxygenases is an O2 sensor, informing the organism the oxygen level in its environment.

Dietary supplement

Alpha-ketoglutaric acid is sold as a dietary supplement and to body builders as AKG or a-KG. Some believe it increases stamina.


Alpha-ketoglutarate can be produced by:
* Oxidative decarboxylation of isocitrate by isocitrate dehydrogenase;
* Oxidative deamination of glutamate by glutamate dehydrogenase.

Alpha-ketoglutarate can be used to produce:
*Creatine-alpha ketoglutarate


"Merck Index", 13th Edition, 5320.

External links

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Look at other dictionaries:

  • alpha-ketoglutaric acid — al·pha ke·to·glu·tar·ic acid or à ketoglutaric acid .kēt ō glü .tar ik n the alpha keto isomer of ketoglutaric acid formed in various metabolic processes (as the Krebs cycle) …   Medical dictionary

  • alpha-ketoglutaric acid — ¦ ̷ ̷  ̷ ̷ ¦ ̷ ̷  ̷ ̷  ̷ ̷ ¦ ̷ ̷  ̷ ̷ noun : the alpha keto isomer of ketoglutaric acid formed in various metabolic processes (as the Krebs cycle) * * * /al feuh kee toh glooh tar ik, al feuh kee /, Biochem. a dibasic keto acid, C5H6O5, that… …   Useful english dictionary

  • alpha-ketoglutaric acid — /al feuh kee toh glooh tar ik, al feuh kee /, Biochem. a dibasic keto acid, C5H6O5, that occurs as an intermediate in the Krebs cycle and in protein metabolism. [1905 10; KETO + glutaric (acid), prob. b. GLUTEN (as in GLUTAMIC ACID) and… …   Universalium

  • alpha-ketoglutaric acid — /ælfə ˌkitoʊgluˌtærɪk ˈæsəd/ (say alfuh .keetohglooh.tarik asuhd) noun a dibasic acid, HOOCCH2.CH2.COCOOH, formed from glutamic acid, and one of the intermediates in the citric acid cycle …  

  • ketoglutaric acid — ke·to·glu·tar·ic acid glü .tar ik n either of two crystalline keto derivatives C5H6O5 of glutaric acid esp ALPHA KETOGLUTARIC ACID …   Medical dictionary

  • ketoglutaric acid — |kēd.ō+(ˌ) ̷ ̷| ̷ ̷ ̷ ̷... noun Etymology: International Scientific Vocabulary ket + glutaric : either of two crystalline keto derivatives of glutaric acid; especially : the alpha keto isomer HOOCCH2CH2COCOOH formed in various metabolic processes …   Useful english dictionary

  • ketoglutaric acid — noun Date: 1908 either of two crystalline keto derivatives C5H6O5 of glutaric acid; especially the alpha keto isomer formed in various metabolic processes (as the Krebs cycle) …   New Collegiate Dictionary

  • alpha-ketoglutarate — al·pha ke·to·glu·ta·rate or à ketoglutarate .al fə .kēt ō glü tä .rāt, glüt ə .rāt n a ketoglutarate of alpha ketoglutaric acid à ketoglutarate, à ketoglutaric acid var of ALPHA KETOGLUTARATE, ALPHA KETOGLUTARIC ACID …   Medical dictionary

  • Complexe alpha-cétoglutarate déshydrogénase — Le complexe alpha cétoglutarate déshydrogénase, également appelé complexe oxoglutarate déshydrogénase (OGDC), est l association de trois enzymes une décarboxylase, une acyltransférase et une oxydo réductase agissant séquentiellement dans cet… …   Wikipédia en Français

  • Creatine-alpha ketoglutarate — is a salt formed from alpha ketoglutaric acid (AKG) and creatine. It is sold as a fitness supplement; however, its effects are experimentally unproven.[1] References ^ Incledon, T; Kreider, RB (2000). Creatine alpha ketoglutarate is… …   Wikipedia

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