Synthesis and antiepileptic activity of some novel semicarbazones containing 1,3,4-thiadiazole and quinazoline ring.

The incomplete seizure control with frequent adverse effects of current anticonvulsant drugs and the importance of semicarbazones, quinazolines and 2,5-disubstituted 1,3,4-thiadiazoles as anticonvulsant pharmacophore prompted us to carry out synthesis of three novel series of semicarbazones containing 1,3,4-thiadiazole and quinazoline ring. The chemical structures of these compounds were elucidated by elemental and spectral (IR, 1H NMR, 13C NMR and MS) analysis. The anticonvulsant activities of the compounds were investigated using maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) models. The rotorod test was conducted to evaluate neurotoxicity. The majority of the compounds were found active in the biological screening. The outcome of the present investigations proved that the four binding sites pharmacophore model is decisive for antiepileptic activity. An attempt has also been performed to establish structure-activity relationships among synthesized compounds.