Acetoacetate, also known as acetoacetic acid, belongs to the class of organic compounds known as short-chain keto acids and derivatives. These are keto acids with an alkyl chain the contains less than 6 carbon atoms. A 3-oxo monocarboxylic acid anion that is the conjugate base of acetoacetic acid, arising from deprotonation of the carboxy group. Acetoacetate is an extremely weak basic (essentially neutral) compound (based on its pKa). In humans, acetoacetate is involved in phenylalanine and tyrosine metabolism. Outside of the human body, acetoacetate has been detected, but not quantified in, several different foods, such as cascade huckleberries, hazelnuts, cherimoya, adzuki beans, and broccoli. Experimental spectrum in Natural Products Magnetic Resonance Database: [NP0044224](https://np-mrd.org/natural_products/452/submission_spectrum_view?spectrum_id=275&spectrum_type=real)