Design, synthesis, and pharmacological evaluation of aryl oxadiazole linked 1,2,4-triazine derivatives as anticonvulsant agents

A series of new clubbed aryl oxadiazole-1,2,4-triazine derivatives (6a-l) were designed and synthesized using appropriate chemical routes. The structures were designed to have the required structural elements for any compounds to be potential anticonvulsant. Preliminary screening of anticonvulsant activity was performed using maximal electroshock seizure (MES), subcutaneous pentylenetetrazole-induced seizure (scPTZ) and behavioral activity were assessed by motor impairment test and actophotometer test. The derivatives 6-((5-(4-methoxyphenyl)-1,3,4-oxadiazol-2-yl)amino)-1,2,4-triazine-3(2H)-thione (6f) and 6-((5-(4-hydroxyphenyl)-1,3,4-oxadiazol-2-yl)amino)-1,2,4-triazine-3(2H)-thione (6g) revealed significant activity against both MES and scPTZ indicating that the compounds are effective against both generalized tonic-clonic and absence seizure. The lead compound (6g) was further evaluated for quantitative evaluation and emerged as the most effective anticonvulsant with median effective dose of 28.5 mg/kg (MES ED50), 76.6 mg/kg (scPTZ) and toxic dose (TD50) was found to be >500 mg/kg. In the GABA estimation study results showed significantly increased GABA concentration.