99% 2-Ketoglutaric acid CAS 328-50-7

What is 2-Ketoglutaric Acid? How does it work?

2-Ketoglutaric acid, also known as α-ketoglutaric acid (also called 2-oxoglutaric acid, α-ketoglutaric acid, 2-oxopentanedioic acid, oxoglutaric acid, AKG), has the chemical formula C5H6O5, a molecular weight of 146.10, CAS number 328-50-7, EINECS 206-330-3, UNII 8ID597Z82X, and InChIKey KPGXRSRHYNQIFN-UHFFFAOYSA-N. It is an α-keto dicarboxylic acid containing one ketone group (C=O) and two carboxyl groups (-COOH). It belongs to the keto acid class of organic compounds and is a key intermediate in the tricarboxylic acid (TCA) cycle and a normal metabolite in the human body. It is an important food and nutritional chemical: a white crystalline powder or crystal with a melting point of approximately 115°C (decomposes), readily soluble in water, ethanol, and methanol; its aqueous solution is acidic and hygroscopic. Due to its properties as a TCA cycle intermediate, an amino acid transamination hub, α-keto acid reactivity, and a dicarboxylic acid taste, food-grade α-ketoglutaric acid is widely used in the food and nutrition fields: it is a core ingredient in sports nutrition supplements (CK-AKG, AAKG, OKG), an approved food flavoring and flavoring agent, and is used in functional beverages.

3-Basic identification information : Chemical formula C5H6O5; Molecular weight 146.10; CAS number 328-50-7; EINECS 206-330-3; UNII 8ID597Z82X; InChIKey KPGXRSRHYNQIFN-UHFFFAOYSA-N; IUPAC name 2-oxopentanedioic acid; ChEBI 30915; ChEMBL 1686; INN name Oxoglurate (Oxogluric Acid); Synonyms: α-ketoglutaric acid, 2-oxoglutaric acid, 2-oxoglutaric acid, alpha-ketoglutaric acid, 2-oxoglutaric acid, oxoglutaric acid, AKG, etc.

Structurally , α-ketoglutarate consists of a ketone group attached to the 2 position of the glutarate backbone and a carboxyl group attached to the 1 and 5 positions. The α-ketone group and the adjacent carboxyl group form an α-keto acid structure, which has high reactivity. It is a product of isocitrate oxidation and decarboxylation in the TCA cycle and is also a keto acid acceptor for the transamination of glutamate.

Physically , α-ketoglutaric acid is a white crystalline powder or crystal with a melting point of about 115℃ (which decomposes simultaneously). It is readily soluble in water, ethanol, and methanol, and slightly soluble in ether and benzene. Its aqueous solution is acidic (dicarboxylic acid) and hygroscopic. When heated above its melting point, it decomposes to release gases such as carbon dioxide. It is relatively stable at room temperature, but its aqueous solution may slowly change color if left to stand for a long time.

Chemically , α-ketoglutarate is an α-keto dicarboxylic acid: the α-keto group (carbonyl group) is electrophilic and can undergo reductive amination, transamination, esterification, condensation and other reactions; under the catalysis of transaminases, it interconverts with glutamate (α-ketoglutarate + amino acid ↔ glutamate + α-keto acid), serving as a hub for amino transfer in the body; its carboxyl group can be esterified and formed into salts (such as arginine salt, creatine salt, ornithine salt used in nutritional supplements); it participates in cellular energy metabolism as an intermediate in the TCA cycle; it also has the ability to chelate metal ions and scavenge reactive oxygen species; the two carboxyl groups endow it with a synergistic flavor profile of sourness and umami.

Why does α-ketoglutarate play these roles in the food and nutrition fields? Its mechanism of action mainly includes the following:

Metabolic intermediate mechanism : α-ketoglutarate is a key intermediate in the tricarboxylic acid cycle and participates in cellular energy metabolism. It is also the hub of the glutamate-α-ketoglutarate transamination system, connecting carbon metabolism and nitrogen metabolism. Supplementing with α-ketoglutarate can provide intermediate substrates for energy supply and amino acid synthesis, which is the physiological basis for its role in sports nutrition and dietary supplementation.

Transamination mechanism : Under the catalysis of transaminases, α-ketoglutarate accepts the amino group of amino acids to generate glutamate and transforms itself into the corresponding α-keto acid. This reaction enables the supplemented α-ketoglutarate to participate in the synthesis and reuse of amino acids in the body and maintain the balance of amino acid metabolism. This is an important mechanism for its use in sports nutrition support .

The synergistic mechanism of sourness and flavor : The two carboxyl groups and the α-keto acid structure endow α-ketoglutaric acid with sourness and produce a synergistic effect with umami substances. It can be used as a food flavoring and flavoring ingredient to adjust the sourness and flavor level, which is the basis for its application in food seasoning and beverage.

Chelation and antioxidant mechanism : The α-keto acid structure can chelate with metal ions and scavenge reactive oxygen free radicals, protecting cells from oxidative damage.

All uses of food-grade 2-Ketoglutaric Acid

1. Sports nutrition supplements (sports nutrition industry)

Corresponding products: Creatine alpha-ketoglutarate (CK-AKG), Arginine alpha-ketoglutarate (AAKG), Ornithine alpha-ketoglutarate (OKG), pre-workout supplements, mass gainer formulas, sports recovery powders, strength training nutrition products, fitness nutrition formula ingredients, etc.

Why it can be used for this purpose: α-Ketoglutarate participates in the TCA cycle and amino acid metabolism, provides intermediate substrates for muscle energy metabolism, and after forming salts with creatine, arginine, ornithine, it has the nutritional effects of both components. As a sports nutrition supplement, it supports energy supply, strength training performance and exercise recovery, and is a common raw material in the fields of bodybuilding and sports nutrition.

2. Dietary supplements (health food industry)

Corresponding products: α-ketoglutarate dietary supplements , energy support tablets, oral powders, health food raw materials, etc.

Why it can be used for this purpose: Alpha-ketoglutarate, as an intermediate in the TCA cycle and an endogenous metabolite, is a popular ingredient in health supplements, and its market application continues to grow with increasing research.

3. Food flavorings and ingredients (food seasoning industry)

Corresponding products: food flavoring formulations, flavor-enhancing ingredients, acidity regulators, compound seasoning components, beverage flavoring ingredients, baking flavoring agents, meat flavoring additives, food ingredients, etc.

Why it can be used for this purpose: α-Ketoglutarate is a flavoring and flavoring ingredient approved for use in food. Its synergistic properties of acidity and umami can regulate the acidity of food and enhance the flavor profile. It is used as a food flavoring and flavoring ingredient in beverage, condiment, and processed food formulations.

4. Ingredients for sports and functional beverages (beverage industry)

Corresponding products: sports drinks, energy drinks, electrolyte drinks, ready-to-drink nutritional drinks, recovery drinks, functional beverage formulas, bottled beverage ingredients, etc.

Why it can be used in this way: α-Ketoglutarate is highly water-soluble and its aqueous solution is acidic. It can be compounded with electrolytes, vitamins, etc. into sports and functional beverages to provide metabolic support components for drinkers. At the same time, its acidity can adjust the taste of the beverage, making it a nutritional ingredient in the formulation of sports and functional beverages.

Summarize

α-Ketoglutaric acid (2-Ketoglutaric acid, CAS 328-50-7) is a dicarboxylic acid containing an α-keto group. Its core properties include being a TCA cycle intermediate, an amino acid transamination hub, and exhibiting α-keto acid reactivity and synergistic acidity. It has wide applications in the food and nutrition fields: in sports nutrition, it is a core component of supplements such as creatine, arginine, and ornithine α-ketoglutaric acid; in food flavoring, it is a flavoring and aromatic ingredient; and in the beverage industry, it is a nutritional ingredient in sports and functional drinks. Understanding its α-keto acid structure and metabolic hub role explains why it can support athletic performance and energy metabolism, regulate flavor, and provide amino acid metabolic support for specific populations—this is why it spans the fields of sports nutrition, health foods, medical foods, flavoring, and beverages.