Drug Design Strategies for the Discovery of Novel Anticonvulsants Concerned with Four Site Binding Pharmacophoric Model Studies

Anticonvulsant refers to a group of pharmaceuticals used in the treatment of epileptic seizures. The use of current antiepileptic drugs has been questioned due to the non selectivity of the drugs and the undesirable side effects produced by them. This led to the search for antiepileptic compounds with more selectivity and lower toxicity. Semicarbazones have been developed as versatile anticonvulsant pharmacophore. It has displayed potent anticonvulsant effect in a wide variety of preclinical anticonvulsant models. Till date various semicarbazone derivatives containing 1,3,4-oxadiazole, 1,3,4- thiadiazole, pyrimidine, benzothiazole and substituted phenyl/aryl ring have been synthesized and evaluated for anticonvulsant activity. The semicarbazone based pharmacophore model with four binding sites is essential for anticonvulsant activity. This model comprises of an aryl hydrophobic binding site, hydrogen bonding domain, an electron donor group and another hydrophobic-hydrophilic site regulating the pharmacokinetic properties of the anticonvulsant. Extensive structure-activity relationship has demonstrated that compound with OH, CH3O, NO2, Cl, F, Br substituents in the arylhydrophobic pocket, nitro, hydroxy group on distant phenyl ring and a hydrogen bonding domain possess anticonvulsant activity. In this review, advances made in the application of semicarbazones as a versatile pharmacophore model for the design of new anticonvulsant drugs are being updated and suggested for future drug design and development of novel anticonvulsants.