2,3-Dihydroxyisovaleric acid

2,3-Dihydroxyisovaleric acid (2,3-Dihydroxy-3-methylbutanoic acid) is a natural metabolite of the branched-chain amino acid leucine that has been found present in the urine of a patient with 2-hydroxyglutaric aciduria ^[1].

References:
[1]. F B Armstrong, et al. Stereoselectivity and stereospecificity of the alpha,beta-dihydroxyacid dehydratase from Salmonella typhimurium. Biochim Biophys Acta. 1977 Jul 21;498(1):282-93.