What is "acetoacetic acid"

n. (context organic compound English) The ketonic carboxylic acid CH₃-CO-CH₂-COOH, that is present in the urine of people suffering from starvation or some forms of diabetes

n. unstable acid found in abnormal amounts in the blood and urine n some cases of impaired metabolism (as diabetes mellitus or starvation)

Acetoacetic acid (also diacetic acid) is the organic compound with the formula CHCOCHCOOH. It is the simplest beta- keto acid group, and like other members of this class it is unstable. The methyl and ethyl esters, which are quite stable, are produced on a large scale industrially as precursors to dyes.

Acetoacetic acid is a weak acid. It is of biochemical importance in various animals, including humans, as one of the endogenous ketone bodies produced by the liver when it breaks down fatty acids into Acetyl-CoA and TCA cycle intermediates are depleted (particularly oxaloacetate, which is formed from pyruvate derived from glycolysis). It can be viewed as the product of joining two acetic acid molecules via a condensation reaction that ejects a water molecule in the process, although that is only one of the ways of forming the acetoacetate molecule. In the human body, a large portion of acetoacetate is converted to beta-hydroxybutyrate, a rich energy source for the brain, which cannot run directly on fatty acids themselves due to their poor ability to cross the blood-brain barrier.