Antimicrobial Properties of Heterocyclic Schiff Base and Their Transition Metal Complexes. "A Review"

Heterocyclic Schiff bases and their transition metal complexes have attracted considerable interest owing to their wide range of biological and pharmacological activities. Schiff bases, synthesized through the condensation of primary amines with carbonyl compounds, contain donor atoms such as nitrogen, oxygen, and sulfur that enable effective coordination with transition metals. The resulting metal complexes generally exhibit enhanced stability and biological activity compared to their free ligand counterparts. Numerous studies have demonstrated that heterocyclic Schiff base metal complexes possess notable antimicrobial activity against a broad spectrum of bacterial and fungal strains, which is often attributed to increased lipophilicity, chelation effects, and improved interactions with biological targets. This review highlights recent progress in the synthesis, characterization, and antimicrobial assessment of heterocyclic Schiff bases and their transition metal complexes, with particular emphasis on structure–activity relationships and their potential applications in medicinal chemistry. Overall, these findings underscore their promise as viable candidates for the development of novel antimicrobial agents to address the growing challenge of drug resistance.