Efficient microwave synthesis of coumarin derivatives with evaluation of their antioxidant and anti-inflammatory properties

Abstract

Microwave radiation, an electromagnetic radiation, is used as a source of heating in organic synthesis. Coumarin, a benzopyrone derivative, shows various pharmacological activities such as anticoagulant, antimicrobial, analgesic, anti-inflammatory. The prime objective was to compare the synthesis of some coumarin derivatives by microwave assisted methods. Two different coumarin derivatives were synthesized and evaluated for their anti-inflammatory activity and anti-oxidant activity. 3-Acetylcoumarin (3-acetyl-2H-Chromen-2- one) was synthesized by reaction with salicylaldehyde and ethyl acetoacetate in presence of piperidine and the 3-acetyl-6-bromocoumarin (3-acetyl-6-bromo-2H-chromen-2-one) was synthesized by using 5-bromo-salicyladehyde. The synthesized compounds were characterized by MP, TLC, IR and NMR. The antioxidant activity of the compounds was done by reducing power by ferric chloride, nitric oxide and hydrogen peroxide scavenging method. The anti-inflammatory activity of the compounds was done by protein denaturation using BSA method. Out of the two compounds synthesized, bromine-substituted acetyl coumarin showed more anti-oxidant and anti-inflammatory activity when compared to standard.