A study of coumarin-derived Schiff base metal complexes and its essential role in pharmacology and computational studies: a review

Coumarin Schiff-base metal complexes have garnered significant interest in medicinal chemistry due to the coumarin scaffold’s synthetic accessibility, low molecular weight, and high biocompatibility. Structural diversification of this core through the incorporation of heterocycles (e.g., pyridine, pyrimidine, thiazole, indole, quinoline) or specific functional groups has proven highly effective in enhancing biological potency. This review underscores the rationale for studying this subclass, highlighting its potential as a versatile pharmacophore with efficient metal chelation and low toxicity. Therefore, we have undertaken a review of coumarin Schiff base metal complexes reported over the past two decades, examining their biomedical applications and highlighting the outcomes of various structural modifications. We elucidate how strategic structural modifications augment bioactivity by fine-tuning lipophilicity, electronic properties, and target selectivity. Surveyed literature demonstrates that metal coordination markedly enhances antimicrobial, anticancer, and antioxidant capabilities compared to the free ligands. These improvements are often attributed to mechanisms such as increased cell permeability and optimized enzyme binding. Furthermore, computational studies, including DFT and Docking, provide critical insights into electronic structures, binding modes, and structure–activity relationships, thereby guiding rational drug design. This review aims to bridge existing research gaps and serve as a foundational resource for advancing these complexes toward therapeutic applications.