ABSTRACT
Two new series of N4-(2, 5-disubstitutedphenyl) semicarbazones were synthesized and evaluated for the anticonvulsant activity in various animal models of seizures. Quantum mechanical modeling was carried out on these compounds to understand the structural features essential for activity. The higher the difference in HOMO and LUMO energy levels the greater was the activity profile. Substitution with fluoro group on the ortho position of the aryl ring was found to decrease the reactivity and hence the activity profile of aryl semicarbazones, which has been justified with the molecular orbital surface analysis of the synthesized compounds.
Subject(s)
Anticonvulsants/chemistry , Models, Molecular , Quantum Theory , Seizures/drug therapy , Semicarbazones/chemistry , Semicarbazones/pharmacology , Animals , Anticonvulsants/chemical synthesis , Anticonvulsants/pharmacology , Disease Models, Animal , Electrons , Semicarbazones/chemical synthesis , Structure-Activity RelationshipABSTRACT
Seven series of various substituted aryl semicarbazones were synthesized and evaluated for anticonvulsant activity in the maximal electroshock seizure (MES) and subcutaneous pentylenetetrazole (scPTZ) induced seizure threshold tests. A comprehensive structure-activity relationship was derived comparing the substituents on the aryl ring and in the carbimino terminal. Generally the order of activity was 4-F > 2-Br = 3-Br = 4-Cl > 4-CH(3) > 4-Br > 3-Cl > 3-CH(3) with respect to the primary aryl group. Most of the compounds exhibited activity both in the MES and scPTZ screens. The 4-fluorophenyl substituted semicarbazones (5a-5y) emerged as the most potent compounds exhibiting anticonvulsant activity in mouse intraperitoneal (i.p.) and rat per oral (p.o.) MES, scPTZ and psychomotor seizure (6 Hz) screens.
