Central Nervous System Agents in Medicinal Chemistry (Formerly Current Medicinal Chemistry - Central Nervous System Agents) - Volume 13, Issue 3, 2013

A series of 12, N-(2-benzoylbenzofuran-3-yl)-3-(substituted)-propanamide analogs was designed and synthesized to meet the pharmacophore requirement essential for anticonvulsant activity. All the compounds were characterized by IR, 1H NMR and mass spectral data followed by their anticonvulsant evaluation according to the Antiepileptic Drug Development Program (ADD) protocol. The present study has proved the hypothesis concerning the pharmacophore model with essential binding sites. N-(2-benzoylbenzofuran-3-yl)-3-(4-(2-fluorophenyl)piperazin-1-yl) propanamide, 6h was found to be the most active compound in both maximal electroshock seizure (MES) and subcutaneous metrazol (scMET) seizure test at 30 and100 mg/kg respectively at 0.5 and 4.0 h.

Catechol-O-methyltransferase (COMT) is the enzyme which catalyzes the transfer of a methyl group from S-adenosylmethionine to catechols and catecholamines, like the neurotransmitters dopamine, epinephrine and norepinephrine. COMT has implications in many neurological and psychiatric disorders like schizophrenia, Parkinson’s disease (PD), bipolar disorders, etc. and therefore, it serves as an important drug target. Since its characterization in 1957, many inhibitors were designed where the first generation inhibitors were found to be highly toxic, short acting and had poor bioavailability. Currently, two of the second generation inhibitors, tolcapone and entacapone have been used for treatment of PD but are associated with various dopaminergic and gastro-intestinal side-effects. There have been several approaches for the design of novel COMT inhibitors with a good and safe therapeutic profile. The focus of this article is to review the current knowledge on COMT and the role of COMT inhibitors in the treatment of neurological disorders. The inhibitors have been classified into six different classes based on the structural framework. A historical overview of the discovery and development of COMT inhibitors is presented with a special emphasis on new generation of inhibitors till date.

In the five membered nitrogen containing heterocyclic family, pyrazoline could be recognized as a promising scaffold for the inhibition of Monoamine oxidase. Substitution at 1, 3 and 5-position of the pyrazoline nucleus displayed a significant activity towards MAO in the past 15 years. Our study identified the detailed structure activity relationship, the structural requirement for enzyme interaction and the effect of chirality on the pyrazoline nucleus towards MAO-A and MAO-B. We propose that the selectivity of pyrazoline nucleus towards MAO isoenzyme depends up on the bulkiness of the ring in the 1 and 3 position of the scaffold. The current review revealed that the derivatives of pyrazolines have proven to be versatile pharmacophores for the inhibition of MAO on the basis of existing literatures between (1998-2013).

A series of 1-(1H-benzimidazol-2-yl)-3-substituted phenylprop-2-en-1-ylidene] amino}-1,3,4-thiadiazole-2- thiols (6a-6f) were synthesized by the acid catalyzed nucleophilic addition reaction between 1-(1H-benzimidazol-2-yl)-3- phenylprop-2-en-1-ones (4a-4f) and 5-amino-1,3,4-thiadiazole-2-thiol. All the synthesized compounds were characterised by IR, 1HNMR, 13CNMR, Mass and elemental analyses. A transition state calculation obtained from DFT study to explore the molecular mechanism of action of the synthetic route. The mechanism of synthesis revealed that the imidazole system can make an increase in the electrophilic character of carbonyl carbon in the benzimidazole chalcones. So the electron deficient carbonyl carbon could be efficiently attacked on the amino group of 1,3,4-thiadiazole ring to forms an imine linkage between the two heterocyclic systems. All the titled derivatives at a dose level of 10mg/kg body weight potentiate the hypnotic action of Phenobarbitone (at a dose of 10mg/kg body weight i.p.). The compounds such as 6b, 6a, and 6c showed a significant percentage increase in sleeping time relative to the control experiment 423.8, 387.6 and 329.5 respectively. The preclinical evaluation of the compounds was ascertained by blood-brain barrier, human oral absorption prediction and in silico toxicity assessment.