Structure activity Relationship Study of Simple Hydroxyl Coumarins as Antioxidant to Scavenge Hydrogen peroxide

Coumarins are heterocyclic compounds; structurally constructed by α-pyrone ring, fused with benzene ring. Coumarins are very interested because of their abundance in nature and their tremendous pharmacological properties such as anticoagulant, anticancer, antibacterial, anti-inflammatory, anti-tuberculosis, antioxidant, etc.The need for the antioxidant is very important because of the role reactive oxygen species and its contribution to many deleterious effects in human body. Hydrogen peroxide is such a reactive oxygen species. This study focused on synthesizing the parent compound,Coumarin and its hydroxyl derivatives (7-hydroxy coumarin and 4-hydroxy coumarin) and studying the positional effect hydroxyl group at 7th and 4thpositions to scavenge the Hydrogen peroxide. The different coumarins were synthesized by using standard methods and werecharacterized by using UV-visible, IR, 1H and 13C NMR spectra. The antioxidant activity of the synthesized coumarins was studied by using standard Hydrogen peroxide scavenging assay. Hydroxyl coumarins showed higher activity than parent coumarin. The 7th positioning hydroxyl group was more effective than 4th positioning hydroxyl group in coumarin to scavenge the Hydrogen peroxide. But all the studied coumarins showed poor hydrogen peroxide scavenging activity when compared to standard ascorbic acid.