Diethyl oxalpropionate also known as methyloxalacetic acid diethyl ester or diethyl methyloxalacetate is a member of the class of compounds known as beta-keto acids and derivatives. These compounds are organic compounds containing an aldehyde substituted with a keto group on the C3 carbon atom.

beta-aminoisobutyric acid is the product from the conversion of N-carbamyl-beta-aminoisobutyric acid by the enzyme Beta-ureidopropionase (EC 3.5.1.6) the last step in pyrimidine degradation. Beta-ureidopropionase deficiency is an inborn error of pyrimidine degradation associated with neurological abnormalities.

Dimethylmalonic acid（2,2-Dimethylmalonic acid） is a short-chain dicarboxylic acid found in human serum that can be used to prevent or retard denaturation of fish actinomyosin in freezing buffer solution (pH 7).