Synthesis, Analgesic, Anti-inflammatory and Antimicrobial Activities of Some Novel Pyrazoline Derivatives

SK Sahu,C Behera,MA Azam,M Banerjee,A Samantray

doi:10.4314/tjpr.v7i2.14664

Abstract

Purpose: Microbial infections often produce pain and inflammation. Chemotherapeutic, analgesic and anti-inflammatory drugs are prescribed simultaneously in normal practice. The compound possessing all three activities is not common.The purpose of the present study was to examine whether molecular modification might result in detection of new potential antirheumatic drugs having antimicrobial activities. Method: A series of novel 4-(5 �-substituted aryl-4�, 5 �-dihydropyrazole-3�-yl-amino) phenols 2a-f have been synthesized by treating substituted aryl-N-chalconyl amino phenols 1a-f with hydrazine hydrate. The starting materials were synthesized from p-aminoacetophenone. Their structures were confirmed by IR, 1 H NMR spectral data. The synthesized compounds were investigated for analgesic, antinflammatory and antimicrobial activities. Result: The data reported in Tables 2, 3 & 4 shows that effect of variation in chemical structure on activity was rather unpredictable. Seldom did a particular structural modification lead to uniform alteration in activity in all tests. The substitution which appeared to be most important for high order of activity in the greatest number of test was the p-choloroaryl group. The introduction of p-nitro and phydroxy group in aryl moiety of the pyrazole analogs 2c and 2e produce compounds with potent analgesic, anti-inflamatory and, in a few cases, antimicrobial properties. Conclusion: The observed increase in analgesic, anti-inflammatory and antimicrobial activities are attributed to the presence of 4-NO 2, 2-OH and 4-Cl in phenyl ring at 5-position of pyrazoline ring of synthesized compounds. In some cases their activities are equal or more potent than the standard drugs.

Highlights

Pyrazole derivatives have a long history of application in agrochemicals and pharmaceutical industry as herbicides and active pharmaceuticals
It has been reported that pyrazoline possess analgesic, anti-inflammatory[1,2,3] and antimicrobial[4,5,6] activities
The general pattern of pharmacological activity encountered in this synthesized compounds was seen mainly in their effect on pain perception and local inflamation.there was a small, well defined antimicrobial activity range associated with many of these compounds

Summary

Introduction

Pyrazole derivatives have a long history of application in agrochemicals and pharmaceutical industry as herbicides and active pharmaceuticals. The recent success of pyrazole COX-2 inhibitor has further highlighted the importance of these heterocycles in medicinal chemistry. A systematic investigation of this class of heterocyclic lead revealed that pyrazole containing pharmacoactive agents play important role in medicinal chemistry. It has been reported that pyrazoline possess analgesic, anti-inflammatory[1,2,3] and antimicrobial[4,5,6] activities. In view of these above, an attempt has been undertaken for the synthesis of the some novel 4-(5′substituted aryl-4′, 5′-dihydropyrazole-3′-ylamino) phenols possessing potent biological activities. The synthesized compounds were tested for their possible analgesic, antiinflammatory and anti-microbial activities

Objectives

Methods

Results

Conclusion