Synthesis and In Vitro Antibacterial Studies of Two New Hydrazone Derivatives

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 the scientific literature as promising candidates for developing new antimicrobial drugs. Two new hydrazones (H3 and H4) incorporating moieties that are known to enhance antimicrobial activity were synthesized. Methods: 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 methods. Results: In-vitro testing demonstrated the compounds’ good activity against the tested organisms, particularly Gram-positive bacteria. At a concentration of 50 mg/mL, H3 produced a zone of inhibition (19 mm) comparable to that of the standard ciprofloxacin (20 mm) at 0.05 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. Conclusions: All the synthesized compounds were proven to possess promising antibacterial activity in vitro against the tested organisms.