Disodium 2-oxoglutarate dihydrate
[CAS# 1282616-74-3]

Identification

• Classification: Organic raw materials >> Carboxylic compounds and derivatives >> Salt of carboxylic acid ester and its derivatives
• Name: Disodium 2-oxoglutarate dihydrate
• Synonyms: a-Ketoglutaric acid disodium dihydrate
• Molecular Formula: C₅H₈Na₂O₇
• Molecular Weight: 226.09
• CAS Registry Number: 1282616-74-3
• SMILES: C(CC(=O)[O-])C(=O)C(=O)[O-].O.O.[Na+].[Na+]

Safety Data

• Hazard Symbols: GHS07 Warning
• Hazard Statements: H302-H315-H319-H335
• Precautionary Statements: P261-P280-P301+P312-P302+P352-P305+P351+P338

Discovory and Applicatios

Disodium 2-oxoglutarate dihydrate is the hydrated disodium salt of 2-oxoglutaric acid, a central metabolite in biological energy metabolism. The discovery of 2-oxoglutarate is inseparable from the elucidation of the tricarboxylic acid cycle, also known as the citric acid cycle, during the first half of the twentieth century. As biochemists sought to understand how carbohydrates, fats, and proteins are oxidized in living cells, systematic studies of organic acids present in tissues revealed a recurring sequence of reactions linking acetate oxidation to carbon dioxide formation. Within this framework, 2-oxoglutarate was identified as a key intermediate connecting carbon metabolism with amino acid transformations.

The role of 2-oxoglutarate in cellular metabolism was firmly established through the work of Hans Krebs and collaborators, who demonstrated its position between isocitrate and succinyl coenzyme A in the citric acid cycle. This discovery highlighted the compound as a pivotal node in oxidative metabolism. Because 2-oxoglutarate carries both keto and dicarboxylate functionalities, it readily participates in enzymatic reactions that involve decarboxylation, oxidation, and transamination. These properties explain its central importance in both energy production and nitrogen metabolism.

The disodium salt form was developed primarily for practical reasons related to solubility, stability, and ease of handling in aqueous systems. Conversion of the free acid to a sodium salt improves water solubility and buffering properties, making it suitable for biochemical experiments, cell culture media, and pharmaceutical formulations. The dihydrate form reflects the compound’s tendency to crystallize with water molecules incorporated into the crystal lattice, a feature that contributes to its stability under normal storage conditions.

Application of disodium 2-oxoglutarate dihydrate spans several scientific and medical fields. In biochemical research, it is widely used as a substrate or cofactor in enzymatic assays. Numerous enzymes, including 2-oxoglutarate dependent dioxygenases, require this molecule to catalyze hydroxylation and demethylation reactions. These enzymes play essential roles in collagen biosynthesis, hypoxia sensing, and epigenetic regulation through histone and DNA demethylation. The availability of a stable, water soluble salt has been critical for in vitro characterization of these enzyme systems.

In physiology and medicine, 2-oxoglutarate has attracted attention because of its role in amino acid metabolism. It serves as a primary amino group acceptor in transamination reactions, linking carbohydrate metabolism with the synthesis and degradation of amino acids such as glutamate and glutamine. Disodium 2-oxoglutarate has therefore been investigated as a nutritional supplement and as a component of parenteral nutrition formulations, where it may support nitrogen balance under specific clinical conditions. These applications are grounded in well established metabolic pathways rather than speculative mechanisms.

The compound has also found application in cell culture and biotechnology. As an intermediate of central metabolism, it can influence cellular growth and differentiation when supplied exogenously under controlled conditions. In microbial and mammalian cell systems, supplementation with 2-oxoglutarate has been used to probe metabolic regulation and to support specific biosynthetic pathways. The disodium dihydrate form ensures reproducible dosing and compatibility with aqueous media.

Overall, the discovery and application of disodium 2-oxoglutarate dihydrate reflect the broader history of biochemistry, in which identification of key metabolic intermediates led to practical tools for research and medicine. Its continued use is based on decades of experimental evidence defining its chemical properties and biological functions, making it an indispensable reagent in studies of metabolism, enzymology, and cellular regulation.

References

Krebs HA, Johnson WA (1937) Metabolism of ketonic acids in animal tissues. Biochemical Journal 31 4 645–660 DOI: 10.1042/bj0310645

Wu G (2009) Amino acids: metabolism, functions, and nutrition. Amino Acids 37 1 1–17 DOI: 10.1007/s00726-009-0269-0