Pharmacological Characterization of Some Selected 4,5-Dihydro-4-oxo-1,2,4-triazolo[1,5-a]quinoxaline-2-carboxylates and 3-Hydroxyquinazoline-2,4-diones as (S)-2-Amino-3-(3-hydroxy-5-methylisoxazol-4-yl)-propionic Acid Receptor Antagonists

Abstract

In the present study, some selected, previously reported 4,5-dihydro-4-oxo-1,2,4-triazolo[1,5-a]quinoxaline-2-carboxylates (TQXs) and 3-hydroxy-quinazoline-2,4-diones (QZs), were evaluated for their affinity at the (S)-2-amino-3-(3-hydroxy-5-methylisoxazol-4-yl)-propionic acid (AMPA) receptor in the [³H]-6-cyano-7-nitroquinoxaline-2,3-dione ([³H]-CNQX) binding assay. Electrophysiological experiments were performed in oocytes expressing rat homomeric GluR3 subunits in order to assess the pharmacological profile of the tested compounds. The binding data, together with those regarding the functional activity, confirmed that most of the TQXs and QZs reported herein are potent AMPA receptor antagonists. When tested for their ability to prevent sound-induced seizures in DBA/2 mice, some of these derivatives showed anticonvulsant properties.