Synthesis Characterization and Biological Activity of Pyrazoline Derivatives as Antimicrobial Agents

Abstract

Introduction: Microbial resistance to antimicrobial agents stagnant residues a main newlinecontest in the medicinal chemistry, as many species of bacteria and fungi have advanced newlineresistance to presently existing antimicrobial drugs. There is a need to focus on newlinedeveloping new molecules to treat infectious diseases due to the resistance acquired by newlinethe microbes towards the chemical compounds on prolonging the interaction. Chalcones newlineand its derivatives have attracted the attention of the chemists owing to their many fold newlinepharmacological activities such as antidepressant and anticonvulsant, MAO inhibitors, newlineantitubercular, cannabinoid receptor antagonist, COX-2 inhibitor, antihepatotoxic newlineactivity. newlineMaterials and methods: The synthesis of pyrazoline from chalcone with hydrazine newlinehydrate and chalcone was prepared by the reaction of substituted acetophenone with newlinesubstituted benzaldehyde. All derivatives were characterized by physical property such as newlinesolubility, melting point and Rf value and spectral analysis (IR, NMR, mass spectra).The newlineantimicrobial activity of pyrazoline derivatives were evaluated against four bacteria and newlinetwo fungus at the 6.25, 12.5 and 25 and#956;g/ml conc. newlineResults: Novel 20 pyrazoline derivatives were synthesized from chalcone. All the newlinepyrazoline derivatives were characterized by physical property (solubility, melting point newlineand Rf value) and spectral studies (IR, NMR and mass spectra). newlineAll derivatives soluble in methanol, chloroform, DMSO but insoluble in ether, benzene, newlineacetone and dimethyl formide. All derivatives had melting point between 300-350 oc. All newlinederivatives were analysed by TLC and the Rf value was found to be between 0.45 to 0.71. newlineAll synthesized derivatives were shown appearance of absorption bands at 1240 cm-1 of newlineCO stretching and 2900-50 cm-1 of CH stretching and 1440 cm-1 of N-N bending of newlinepyrazoline ring in FT-IR spectrum clearly indicated, the formation of pyrazoline ring. newlineThis fact was further supported by appearance of a singlet of and#948; 3.83 corresponding to newlineprotons of O-CH3 proton and three triplets at