Potent and selective GluK1 (formally GluR5)-subunit containing kainate receptor antagonist (apparent KD = 402 nM); active enantiomer of UBP 296 (Cat. No. 2078). Displays ~ 260-fold selectivity over AMPA receptors, ~ 90-fold selectivity over recombinant human GluK2 (formally GluR6) and GluK5 (formally KA2)-containing kainate receptors and has little or no action at NMDA or group I mGlu receptors. Selectively blocks kainate receptor-mediated LTP induction in rat hippocampal mossy fibers. Also protects against soman-induced seizures and neuronal degeneration for up to 30 days when administered one hour after soman exposure. Please refer to IUPHAR Guide to Pharmacology for the most recent naming conventions. Purity 98%. MW (observed): 333.3