Design, Synthesis and Evaluation of Antibacterial Activity of Novel Indazole Derivatives

A series of novel indazole derivatives have been designed and synthesized by a novel method and evaluated for their antibacterial activity. The compounds were designed to study their interactions as inhibitor of DNA gyrase B. Salicylaldehyde and hydrazine hydrate have been refluxed along with polyethylene glycol and catalytic amount of ptoluenesulfonic acid to yield desired compounds. All the synthesized compounds were subjected to in vitro anti-bacterial activity studies against B. Subtilis, S. aureus, E. coli, P. Aeruiginosa and S. typhi. Substituted compounds I5, I9 and I13 exhibited significant inhibition of bacterial growth. The MIC value of these 3 compounds was found to be 50µg/mL. Compounds substituted at 5th and 6th position of indazole were found to show better hydrogen bond interactions with DNA gyrase B and appreciable potential for anti-bacterial activity. They can be used as potential molecule in bacterial resistance cases. The present studies will be useful for designing selective compounds for inhibition of DNA gyrase B. Keywords: Hydrazine hydrate, minimum inhibitory concentration, polyethylene glycol, p-toluenesulfonic acid, salicylaldehyde.