Potent and competitive kynurenine 3-monooxygenase (kynurenine 3-hydroxylase; KMO) inhibitor (Ki = 4.8 nM, IC50 = 37 nM). Increases kynurenic acid levels to concentrations that antagonize the glycine site of NMDA receptors. Brain penetrant and exhibits antidystonic, anticonvulsant and neuroprotective activities. Purity 99%. MW (observed): 421.45