A Review of Synthesis and Therapeutic Applications of Coumarin Derivatives

Coumarins (2H-1-benzopyran-2-ones) are heterocyclic compounds widely distributed in plants, fruits, and vegetables, exhibiting significant pharmacological properties. The coumarin scaffold acts as a good template for drug development due to its structural simplicity and broad spectrum of biological activities. Modern synthetic approaches including gold-catalyzed cyclization, rhodium-catalyzed annulation, palladium-mediated coupling, and green chemistry methods have enabled efficient production of structurally diverse coumarin derivatives. The biological significance of coumarins encompasses anti-inflammatory, anticoagulant, antimicrobial, antiviral, and anticancer properties. Natural coumarins such as imperatorin and osthole show therapeutic effects against inflammation, microbial infections, and cancer. Structure-activity relationship studies have led to the development of synthetic derivatives with enhanced pharmacological profiles. The coumarin nucleus allows strategic modifications at multiple positions, resulting in compounds with improved efficacy and reduced toxicity. Recent synthetic methodologies emphasize sustainable protocols and efficient routes to complex coumarin derivatives. Emerging applications include the development of antidiabetic, neuroprotective, and antituberculosis agents. The low toxicity, natural abundance, and synthetic accessibility of coumarins position them as potential entities for drug discovery and development.