2-Ketoglutaric acid

Molecular Structure of 2-Ketoglutaric acid (CAS NO.328-50-7):

IUPAC Name: 2-oxopentanedioic acid 
Empirical Formula: C₅H₆O₅
Molecular Weight: 146.0981
H bond acceptors: 5
H bond donors: 2
Freely Rotating Bonds: 4
Polar Surface Area: 69.67 Å²
Index of Refraction: 1.494
Molar Refractivity: 28.37 cm³
Molar Volume: 97.4 cm³
Surface Tension: 67.9 dyne/cm
Density: 1.499 g/cm³
Flash Point: 177 °C
Enthalpy of Vaporization: 64.8 kJ/mol
Boiling Point: 345.6 °C at 760 mmHg
Vapour Pressure: 1.08E-05 mmHg at 25°C
Melting point: 113-115 °C
FEMA: 3891
Storage temp: 2-8°C
Merck: 14,5303
BRN: 1705689
InChI
InChI=1/C5H6O5/c6-3(5(9)10)1-2-4(7)8/h1-2H2,(H,7,8)(H,9,10)
Smiles
C(CCC(=O)O)(C(O)=O)=O
Product Categories: Pharmaceutical Intermediates; Aliphatics; Organic acids; Amino Acids; Food Additives

 The usage of  2-Ketoglutaric acid (CAS NO.328-50-7):

 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.
Krebs cycle: 2-Ketoglutaric acid 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 α-ketoglutarate from transamination of glutamate, or through action of glutamate dehydrogenase on glutamate. Dietary supplement: 2-Ketoglutaric acid is sold as a dietary supplement and to body builders as AKG or a-KG. Some believe it increases stamina.

Nitrogen transporter: Another function is to combine with nitrogen released in the cell, therefore preventing nitrogen overload.
α-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. 2-Ketoglutaric acid 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, α-ketoglutarate helps the reaction by being oxidized together with the main substrate. In fact, one of the α-ketoglutarate-dependent oxygenases is an O₂ sensor, informing the organism the oxygen level in its environment.

The Risk Statements information:
23/24/25:  Toxic by inhalation, in contact with skin and if swallowed 
36/37/38:  Irritating to eyes, respiratory system and skin 
37/38:  Irritating to respiratory system and skin 
The Safety Statements information:
26:  In case of contact with eyes, rinse immediately with plenty of water and seek medical advice 
39:  Wear eye/face protection  
45:  In case of accident or if you feel unwell, seek medical advice immediately (show label where possible) 
36/37/39:  Wear suitable protective clothing, gloves and eye/face protection 
The Hazard Codes of  2-Ketoglutaric acid (CAS NO.328-50-7):   Xi,   T
WGK Germany: 3
HS Code: 29183000