Methylmalonic acid-d₃is intended for use as an internal standard for the quantification of methylmalonic acid by GC- or LC-MS. Methylmalonic acid is a dicarboxylic acid and byproduct of propionate catabolism.¹It impairs mitochondrial respiration, increases glucose consumption, and downregulates the transcription of the mature neuronal markers neuron-specific enolase (ENO2) and synaptophysin (SYP) in neuronally differentiated SH-SY5Y cells. Intrastriatal administration of methylmalonic acid (100 mg/ml) induces neuronal loss in rats.²Methylmalonic acid accumulates in the tissues and body fluids of patients with methylmalonic acidemia, an inborn error of metabolism characterized by a deficiency in the activity of L-methylmaolnyl-CoA mutase or its cofactor 5-deoxyadenosylcobalamin and leads to seizures, intellectual disabilities, psychomotor abnormalities, and coma.¹

1.da Costa, R.T., Dos Santos, M.B., Silva, I.C.S., et al.Methylmalonic acid compromises respiration and reduces the expression of differentiation markers of SH-SY5Y human neuroblastoma cellsACS Chem. Neurosci.12(14)2608-2618(2021) 2.Narasimhan, P., Sklar, R., Murrell, M., et al.Methylmalonyl-CoA mutase induction by cerebral ischemia and neurotoxicity of the mitochondrial toxin methylmalonic acidJ. Neurosci.16(22)7336-7346(1996)