Synthesis of N⁴-(2,4-dimethylphenyl) semicarbazones as 4-aminobutyrate aminotransferase inhibitors

Several 2,4-dimethylphenyl substituted semicarbazones were synthesized in three steps involving aryl urea and aryl semicarbazide formation. The structures were confirmed by spectral and elemental analyses. All the compounds were evaluated for anticonvulsant activity by using a series of test models, including maximal electroshock seizure, subcutaneous pentylenetetrazole and subcutaneous strychnine seizure threshold tests. The compounds were also evaluated for behavioural impairement and depression activity. In the neurochemical investigation, potent compounds were evaluated for their effects on rat brain γ-aminobutyric acid (GABA) levels and in vitro γ-aminobutyrate transaminase (Pseudomonas fluorescens) activity. Preliminary studies suggest that these compounds exhibit anticonvulsant activity via a GABA-mediated mechanism.