Synthesis and Antimicrobial Activity of Chalcone-Derived 1,4-Dihydropyridine Derivatives Using Magnetic Fe2O3@SiO2 as Highly Efficient Nanocatalyst

The growing threat of bacterial resistance, coupled with the increasing costs associated with drug development, poses significant challenges in the discovery of new antibiotics. The present study reports the synthesis and antimicrobial evaluation of 1,4-dihydropyridine (1,4-DHP) derivatives derived from chalcones, using silica-mediated magnetic iron oxide, Fe2O3@SiO2 nanoparticles as a nanocatalyst. The nanoparticles were characterized using FT-IR, SEM-EDS, XRD, Zeta-Potential, and VSM techniques to confirm their structure and properties. Among them, the series 8a–e (particularly compound 8c) demonstrated strong antimicrobial activity, with effectiveness comparable to standard drugs Fluconazole and Amoxicillin; this was attributed to the presence of polar groups. Other derivatives exhibited moderate activity, with MICs ranging from 25 to 50 μg/mL, while no significant activity was observed against Gram-negative bacteria. These compounds hold potential as promising antimicrobial agents and warrant further investigation for the development of effective therapies.