2-Hydroxy-3-(1-methylethyl)-butanedioic acid is an organic compound that is a metabolite of the amino acid methionine. It is formed by the oxidation of the methyl group on the 2 position in methionine. The protein subunits are expressed in liver cells and it has been shown to have antioxidant properties. The analytical methods used for this compound include LC-MS/MS, which separates it into its individual isomers. This method can be used to determine the purity of 2-hydroxy-3-(1-methylethyl)-butanedioic acid. The carbonyl group in this molecule makes it susceptible to steric interactions with other molecules, which may lead to it being oxidized or reduced. It has been found that 2-hydroxy-3-(1-methylethyl)-butanedioic acid shows thermophilic and enterocolitic properties.