Oxoglutarate

Oxoglutarate, also known as alpha-ketoglutarate (AKG) or 2-oxoglutarate, is a five-carbon dicarboxylic acid containing a keto group at the second carbon. In metabolic contexts it is usually considered in its deprotonated form, 2-oxoglutarate, and it plays a central role in cellular energy metabolism.

In the citric acid cycle, alpha-ketoglutarate is formed from isocitrate by isocitrate dehydrogenase and is subsequently converted to succinyl-CoA by alpha-ketoglutarate dehydrogenase, generating NADH and releasing carbon dioxide. Beyond its role in energy production, AKG serves as an amino group acceptor in transamination reactions, forming glutamate. This links carbon and nitrogen metabolism and provides a key node for the biosynthesis of other amino acids and nucleotides.

Oxoglutarate is produced endogenously in most organisms and can also be obtained from dietary sources. It is marketed as a dietary supplement in the form of calcium alpha-ketoglutarate or magnesium alpha-ketoglutarate salts. These supplements are used in various contexts with proposed benefits related to energy metabolism, protein synthesis, and recovery, though the clinical evidence is varied and often inconclusive.

Safety and regulatory considerations apply to AKG supplementation. Typical doses are generally well tolerated, but possible gastrointestinal upset and mineral chelation can occur, and individuals with kidney disease or those taking certain medications should consult a healthcare professional before use. As a metabolic intermediate, oxoglutarate remains a focus of research for its roles in energy production and nitrogen metabolism.