Synthesis and In-vitro antibacterial studies of new hydrazone derivatives

Abstract: Throughout history to the present day, infectious diseases have been a persistent global threat, causing significant harm to public health and economic stability. To address these challenges, the development of novel antimicrobial drugs is crucial. Hydrazones have gained significant attention in scientific literature as promising candidates for developing new antimicrobial drugs. Two new hydrazone (H3 and H4) incorporating moieties that are known to enhance the antimicrobial activity were synthesized. Method: The hydrazone derivatives were synthesized through a condensation reaction of substituted acetophenone and nitro phenyl hydrazine. The compounds were characterized by their melting points and spectral analyses, including FT-IR, ¹H NMR, ¹³C NMR, and 2D NMR. Their antibacterial effects on Escherichia coli and Staphylococcus aureus, were assessed in-vitro using the agar diffusion and broth dilution method. Result: In-vitro testing demonstrated good activity against tested organisms, particularly gram-positive bacteria. At a concentration of 50 mg/ml, H3 produces zone of inhibition (19 mm) comparable to the standard ciprofloxacin (20 mm) at 0.05 mg/ml. P5 produces less inhibition in comparison to H3 and H4 producing minimum inhibition (12 mm) at highest concentration of 50 mg/ml. Only H3 was able to kill both Staphylococcus aureus and Escherichia coli at a concentration of 50 mg/ml. In all cases, H3 was found to be the most effective with optimum bactericidal and bacteriostatic activity against staphylococcus aureus and Escherichia coli. Conclusion: All the synthesized compounds were proven to possess a promising antibacterial activity in-vitro against tested organism.