pantoic acid
{{Chembox
| ImageFile = D-pantoic acid.svg
| ImageSize = 200px
| PIN = (2R)-2,4-Dihydroxy-3,3-dimethylbutanoic acid
| OtherNames = D-Pantoic acid; D-Pantoate; B(R)-2,4-dihydroxy-3,3-dimethylbutanoic acid
|Section1={{Chembox Identifiers
| CASNo = 1112-33-0
| CASNo_Ref = {{cascite|correct|}}
| UNII_Ref = {{fdacite|correct|FDA}}
| UNII = 0J1TL6G6J9
| PubChem = 439251
| ChemSpiderID = 388387
| SMILES = O=C(O)[C@H](O)C(C)(C)CO
| StdInChI = 1S/C6H12O4/c1-6(2,3-7)4(8)5(9)10/h4,7-8H,3H2,1-2H3,(H,9,10)/t4-/m0/s1
| StdInChIKey = OTOIIPJYVQJATP-BYPYZUCNSA-N
}}
|Section2={{Chembox Properties
| C=6 | H=12 | O=4
| Appearance =
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| MeltingPt =
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|Section3={{Chembox Hazards
| MainHazards =
| FlashPt =
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Pantoic acid is the alpha hydroxy acid with the formula HOCH2C(CH3)2CH(OH)CO2H. The compound is almost always encountered in a biological context, as an aqueous solution of its conjugate base pantoate HOCH2C(CH3)2CH(OH)CO2-. The amide of pantoic acid with β-alanine is pantothenic acid (vitamin B5),[http://www.merriam-webster.com/medical/pantoic%20acid Pantoic acid], Merriam Webster Medical Dictionary a component of coenzyme A.
Biosynthesis
Its biosynthesis proceeds from ketoisovalerate by hydroxymethylation:
:(CH3)2CHC(O)CO2− + CH2O → HOCH2(CH3)2CC(O)CO2−
This conversion is catalyzed by ketopantoate hydroxymethyltransferase, which gives ketopantoate. Ketopantoate is reduced by ketopantoate reductase to pantoate, using NADH as the hydride source.{{cite book |doi=10.1016/S0083-6729(01)61005-7|chapter=The Biosynthesis of Coenzyme a in Bacteria|title=Cofactor Biosynthesis|series=Vitamins & Hormones|year=2001|last1=Begley|first1=Tadhg P.|last2=Kinsland|first2=Cynthia|last3=Strauss|first3=Erick|volume=61|pages=157–171|pmid=11153265|isbn=9780127098616}}
The amide derived from pantoic acid and GABA is the pharmaceutical drug hopantenic acid.
References
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