Anthelmintic and anti-filarial coumarins of natural and synthetic origin: Chemical and biological intervention

Abstract

Coumarin is a bicyclic system with a lactone-(hetero)aryl motif and a critical structural unit of many natural and synthetic pharmaceutical compounds. The coumarins possess a broad spectrum of biological activities and have successful clinical applications. Several coumarin-based natural compounds like osthol, isopimpinellin, umbelliferon, scopoletin, scopoline, cleomiscosin A to D, and inophyllum E have been isolated with anthelmintic and antifilarial activities. The ability of coumarin to interact with various active sites through noncovalent interactions like van der Waals forces, metal coordination, electrostatic and hydrophobic interaction, as well as hydrogen bonding, have led to the synthesis of different coumarins with significant anthelmintic and anti-filarial activities. The SAR studies of parasitic coumarins revealed that a hydroxy group at C-4 and C-7 positions has a deciding role in the anthelmintic and anti-filarial activity. The careful structure–activity studies could be effectively employed in the structural optimization of the bicyclic coumarin ring, allowing it to have many derivatives that could be screened for helminthiases. We hope this review will provide a structure-based input to researchers to design and develop novel coumarin hybrids to treat helminthiasis and filariasis.

Keywords

• Coumarin metal complexes
• Anthelmintic coumarins
• Anti-filarial coumarins
• Coumarin-heteroaryl hybrids
• Benzopyrones