Pantoic acid

Pantoic acid is the alpha hydroxy acid with the formula HOCH₂C₂CHCO₂H. The compound is almost always encountered in a biological context, as an aqueous solution of its conjugate base pantoate HOCH₂C₂CHCO₂-. The amide of pantoic acid with β-alanine is pantothenic acid, a component of coenzyme A.

Biosynthesis

Its biosynthesis proceeds from ketoisovalerate by hydroxymethylation:
This conversion is catalyzed by ketopantoate hydroxymethyltransferase, which gives ketopantoic acid. This compound is reduced by ketopantoate reductase to -pantoic acid, using NADPH as the hydride source.
The amide derived from pantoic acid and GABA is the pharmaceutical drug hopantenic acid.