Α-Ketobutyric acid

α-Ketobutyric acid
Names


Preferred IUPAC name 2-Oxobutanoic acid
Identifiers
CAS Number	600-18-0^Y
3D model (JSmol)	Interactive image
ChEBI	CHEBI:30831^Y
ChEMBL	ChEMBL171246^Y
ChemSpider	57^Y
DrugBank	DB04553^Y
ECHA InfoCard	100.009.080
EC Number	209-986-9
KEGG	C00109^Y
MeSH	Alpha-ketobutyric+acid
PubChem CID	58
UNII	B92RB6HY1A^Y
CompTox Dashboard (EPA)	DTXSID9060524
InChI InChI=1S/C4H6O3/c1-2-3(5)4(6)7/h2H2,1H3,(H,6,7)^Y Key: TYEYBOSBBBHJIV-UHFFFAOYSA-N^Y InChI=1/C4H6O3/c1-2-3(5)4(6)7/h2H2,1H3,(H,6,7) Key: TYEYBOSBBBHJIV-UHFFFAOYAT
SMILES O=C(C(=O)O)CC
Properties
Chemical formula	C₄H₆O₃
Molar mass	102.089 g/mol
Appearance	colorless solid
Melting point	33 °C (91 °F; 306 K)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Y verify (what is ^YN ?) Infobox references

Chemical compound

α-Ketobutyric acid is an organic compound with the formula CH₃CH₂C(O)CO₂H. It is a colorless solid that melts just above room temperature. Its conjugate base α-ketobutyrate is the predominant form found in nature (near neutral pH). It results from the lysis of cystathionine. It is also one of the degradation products of threonine, produced by the catabolism of the amino acid by threonine dehydratase. It is also produced by the degradation of homocysteine and the metabolism of methionine.

α-Ketobutyrate is transported into the mitochondrial matrix, where it is converted to propionyl-CoA by branched-chain alpha-keto acid dehydrogenase complex. Further mitochondrial reactions produce succinyl-CoA. This is first through the enzyme mitochondria propionyl-CoA carboxylase with biotin as a cofactor to produce (S)-methylmalonyl-CoA. This is subsequently converted to (R)-methylmalonyl-CoA by mitochondrial methylmalonyl-CoA epimerase. Finally, mitochondrial methylmalonyl-CoA mutase with cofactor adenosylcobalamin produces succinyl-CoA which enters the citric acid cycle.^[1]

Conversion in sotolon in French vin jaune

Vin jaune is marked by the formation of sotolon from alpha-ketobutyric acid.^[2]^[3]

References

^ http://smpdb.ca/ ^{[not specific enough to verify]}
^ Pham TT, Guichard E, Schlich P, Charpentier C (1995). "Optimal Conditions for the Formation of Sotolon from α-Ketobutyric Acid in the French 'Vin Jaune'". Journal of Agricultural and Food Chemistry. 43 (10): 2616–2619. doi:10.1021/jf00058a012.
^ Guichard E, Pham TT, Etievant P (1993). "Quantitative Determination of Sotolon in Wines by High-Performance Liquid Chromatography". Chromatographia. 37 (9–10): 539–542. doi:10.1007/BF02275793. S2CID 95494741.

Amino acid metabolism metabolic intermediates

K→acetyl-CoA

lysine→	Saccharopine Allysine α-Aminoadipic acid 2-Oxoadipic acid Glutaryl-CoA Glutaconyl-CoA Crotonyl-CoA β-Hydroxybutyryl-CoA
leucine→	β-Hydroxy β-methylbutyric acid β-Hydroxy β-methylbutyryl-CoA Isovaleryl-CoA α-Ketoisocaproic acid β-Ketoisocaproic acid β-Ketoisocaproyl-CoA β-Leucine β-Methylcrotonyl-CoA β-Methylglutaconyl-CoA β-Hydroxy β-methylglutaryl-CoA
tryptophan→alanine→	N′-Formylkynurenine Kynurenine Anthranilic acid 3-Hydroxykynurenine 3-Hydroxyanthranilic acid 2-Amino-3-carboxymuconic semialdehyde 2-Aminomuconic semialdehyde 2-Aminomuconic acid Glutaryl-CoA

G→pyruvate→
citrate

glycine→ serine→	3-Phosphoglyceric acid glycine→creatine: Glycocyamine Phosphocreatine Creatinine

G→glutamate→
α-ketoglutarate

histidine→	Urocanic acid Imidazol-4-one-5-propionic acid Formiminoglutamic acid Glutamate-1-semialdehyde
proline→	1-Pyrroline-5-carboxylic acid
arginine→	Agmatine Ornithine Citrulline Cadaverine Putrescine
other	cysteine+glutamate→glutathione: γ-Glutamylcysteine

G→propionyl-CoA→
succinyl-CoA

valine→	α-Ketoisovaleric acid Isobutyryl-CoA Methacrylyl-CoA 3-Hydroxyisobutyryl-CoA 3-Hydroxyisobutyric acid 2-Methyl-3-oxopropanoic acid
isoleucine→	2,3-Dihydroxy-3-methylpentanoic acid 2-Methylbutyryl-CoA Tiglyl-CoA 2-Methylacetoacetyl-CoA
methionine→	generation of homocysteine: S-Adenosyl methionine S-Adenosyl-L-homocysteine Homocysteine conversion to cysteine: Cystathionine α-Ketobutyric acid + Cysteine
threonine→	α-Ketobutyric acid
propionyl-CoA→	Methylmalonyl-CoA