[{"from": "human", "value": "Describe this molecule. [C][C][C][Branch1][C][C][C][=Branch1][C][=O][C][=Branch1][C][=O][O]"}, {"from": "gpt", "value": "The molecule is a metabolite of isoleucine in man, animals and bacteria. It is the alpha-keto acid analogue of isoleucine. 3-Methyl-2-oxovaleric acid is produced from isoleucine by cytosolic branched chain aminotransferase 1 (EC:2.6.1.42), whereupon it is further degraded by branched chain keto acid dehydrogenase E1 to 2-Methyl-1-hydroxybutyl-ThPP. It is used as a clinical marker for maple syrup urine disease (MSUD). MSUD is caused by a deficiency of the branched-chain -keto acid dehydrogenase compex resulting in an accumulation of branched-chain amino acids and the corresponding -keto-and -hydroxy acids in blood, urine and cerebrospinal fluid causing neurological damage and mental retardation."}]