Coumarins: an Overview of Medicinal Chemistry. Potential for New Drug Molecules

Fusion of a pyrone ring with a benzene nucleus gives rise to a class of heterocyclic compounds called Benzopyrones, of which two distinct types are recognized: (1) benzo-α-pyrone commomly called coumarins and (2) benzo-Υ-pyrone called chromones or flavanoids, latter differing from former only in the position of the carbonyl group in heterocyclic system. Coumarins have attracted considerable attention of medicinal chemists and pharmacologists in recent years as they been demonstrated to bear various pharmacological activities like anti microbial, anti oxidant, anti inflammatory and analgesic, anti cancer, ulcerogenic, anti malarial, antihyperlipidemic, tyrosinase inhibitor, anti convulsant, anti-parkinsonian, antihepatitis, anticoagulant, cholinesterase inhibitor, vasorelaxant. This review focus on therapeutic importance of coumarins along with various methods of synthesis. INTRODUCTION: Coumarins are cinnamic acid derived phenolic compounds which are found in fungi, bacteria and plants, particularly in edible plants of different botanical families. The name coumarin is derived from `coumarou’, which is the vernacular name of Tonka bean (Dipteryx odorata willd, Fabaceae), from which coumarin was isolated in 1820 1 . Coumarin comes under the benzopyrone family of compounds, all of which consist of a benzene ring joined to a pyrone ring 2 . Coumarins can be subdivided into two categories: QUICK RESPONSE CODE DOI: 10.13040/IJPSR.0975-8232.7(2).482-04 Article can be accessed online on: www.ijpsr.com DOI link: http://dx.doi.org/10.13040/IJPSR.0975-8232.7 (2).482-04 (1) benzo-α-pyrone commonly called as coumarins (2) benzo-Υ-pyrones called as chromones or flavanoids, differs only in the position of carbonyl group on the heterocyclic system. O O FIG. 1: 2-H CHROMEN-2-ONE COUMARIN Some important compounds isolated from coumarin are Warfarin, Acenocoumarol, Armillarisin A, Novobiocin, Clorobiocin, Hymecromone etc. coumarin and its derivatives could be synthesized in laboratory by Pechmann reaction, perkin reaction, Reformatsky reaction and Knovenegal reaction. Coumarins have been under extensive studies for their versatile biodynamic activities, for example coumarins with phenolic hydroxyl group have the ability to scavenge reactive oxygen species and thus prevent the formation of 5HETE and 5HHT in arachadonic