A review on coumarin backbone: An attractive scaffold for promising bioactive compounds

Abstract

Background: Coumarin moiety is found in many naturally occurring products that have been used for many decades in traditional medicine around the world. Coumarin has distinctive physicochemical properties and can be easily transformed into a wide range of functionalized coumarins. As a result, a large number of coumarin derivatives have been designed, synthesized, and evaluated to attack a variety of pharmacological targets selectively. These targets may include various selective enzyme inhibitors and the targets, tagged as multitarget-directed ligands, found in diseases like Parkinson's and Alzheimer's, which are considered as multifactorial diseases. Objectives: The most widely used synthetic methods leading to coumarins, besides the major biological routes for their metabolic transformations and biosynthesis, are highlighted and reviewed. Also, the focus was concentrated on some pharmacological activities of coumarin derivatives involving those related to the selective inhibition of cholinesterase and monoamine oxidase enzymes and targeting specific ligands of neurodegenerative diseases. Conclusion: The impacts of substituents pattern/type on the selectivity and potency of the studied coumarins were explained to determine the main structural and molecular factors that may affect the activity and performance of the directed targets.