High affinity and selective negative modulator of AMPA receptors containing TARP-γ8 (Ki = 26 nM). Exhibits <50% binding against a panel of 52 receptors, ion channels and transporters (except 5HT2B and melatonin receptors 78% and 57%, respectively). Also displays minimal activity against other TARP-less AMPARs and AMPARs coexpressed with other TARPs or CNIH2. Orally bioavailable and brain penetrant. Anticonvulsant. Purity 98%. MW (observed): 328.67