Schiff Base Derivatives: Synthesis, Characterisation, and Antimicrobial Potential – A Comprehensive Review

Abstract

The growing emergence of multidrug-resistant pathogens has renewed scientific interest in chemical scaffolds capable of yielding novel antimicrobial leads. Schiff bases, a class of compounds characterised by the azomethine (>C=N–) linkage, have re-emerged as one of the most versatile templates in medicinal and coordination chemistry. The present review consolidates the current understanding of Schiff base derivatives, with particular emphasis on their synthetic strategies, spectroscopic and physicochemical characterisation, and antimicrobial profiles against clinically relevant bacterial and fungal strains. Conventional condensation between primary amines and carbonyl compounds, alongside contemporary green protocols such as microwave-assisted, ultrasound-assisted and solvent-free grinding methods, are critically compared. Structural elucidation strategies employing UV–visible, FT-IR, ¹H- and ¹³C-NMR, and mass spectrometry are summarised. The antimicrobial behaviour of representative Schiff bases and their metal complexes is interpreted through chelation theory, modulation of lipophilicity, and disruption of microbial enzymatic systems. Evidence from recent literature confirms that suitable substitution at the azomethine carbon and on the aromatic rings significantly improves activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger. The review concludes that Schiff bases constitute a privileged scaffold whose rational design may deliver next-generation antimicrobial agents.

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