Design and synthesis of pyrazolyl thiosemicarbazones as new anticonvulsants

Abstract

A series of pyrazolyl thiosemicarbazone derivatives were synthesized and evaluated for their anticonvulsant activity using the maximal electroshock (MES) method. Interestingly, all compounds prepared showed long duration of protection effect in the MES screens. Among them, compound 5b was considered as the most promising one with an ED50 value of 47.3 mg/kg, and a PI value of 4.8, which was superior to phenobarbital and valproate in the aspect of safety. Furthermore, compound 5b showed protection against seizures induced by pentylenetetrazole suggesting that compound 5b may exert anticonvulsant activity through GABA-mediated mechanisms.