This study aimed to synthesize, characterize, and evaluate the antimicrobial activity and cytotoxicity of various acylhydrazones derived from 2-, 3-, or 4-iodobenzoic acid.

Two synthesis methods were employed to produce nicotinamides from nicotinic acid and various mono-thiocarbohydrazones, yielding several compounds with characterized chemical properties.

The synthesis utilized both standard solution methods and mechanochemical techniques, demonstrating effective solvent-free preparation of compounds.

The study aimed to chemically characterize newly synthesized nicotinamides and evaluate their antimicrobial activity against WHO-prioritized resistant strains.

The outcome of microbiological tests showed varying antimicrobial effects among the synthesized compounds, with some demonstrating significant activity against Gram-positive bacteria and yeasts.

Compounds 12 and 14 showed the broadest antimicrobial effects against Gram-positive bacteria, while compound 20 displayed activity against both Gram-positive and Gram-negative bacteria.

The synthesized nicotinamides exhibited varying degrees of antimicrobial activity, and results were statistically analyzed for significance in comparison to control antibiotics.

Overall, the study highlights the potential of acylhydrazones as promising antimicrobial agents, though further research is necessary to optimize their efficacy and reduce toxicity.

Research is underway to explore alternative antimicrobial strategies, including the use of plant extracts, metal ions, and nanoparticles that may help combat drug-resistant pathogens.

Antimicrobial resistance (AMR) is responsible for an estimated five million deaths annually worldwide, posing a significant global public health threat.

Resistance to all antimicrobials used in human medicine has been reported, with a concerning rise in carbapenem-resistant bacteria and vancomycin-resistant Enterococcus in Europe from 2017 to 2021.

Emerging antifungal resistance exacerbates the challenge of invasive fungal diseases (IFD), particularly among new at-risk groups identified during the COVID-19 pandemic.