Synthesis, Spectral Studies and Antimicrobial Activity of Coumarin Derivatives

Abstract

An antimicrobial is a substance that kills or inhibits the growth of microorganisms such as bacteria, fungi, or protozoans. Microorganisms have existed on the earth for more than 3.8 billion years and exhibited the greatest genetic and metabolic diversities. They are an essential component of the biosphere and serve an important role in the maintenance and sustainability of ecosystems. Heterocyclic compounds are cyclic compounds with the ring containing one or more atom other than carbon. The fusion of pyrone ring with benzene nucleus give rise to a class of heterocyclic compound known as benzopyrone, of which two distinct types are recognized: Benzo-α-pyrone commonly called as coumarin. Benzo-γ-pyrone commonly called as chromon. In the present study involves synthesis of substituted 2-((4-methyl-2-oxo-2H-chromen-7-yl)oxy) acetamide derivatives. The synthesized derivatives were evaluated for antibacterial activity using two strains viz. Staphylococcus aureus (MTCC 3160) and Shigella flexneri (MTCC 1457). The synthesized derivatives were also evaluated for antifungal activity using strain Candida albicans (MTCC 227). The antibacterial activity data indicate that certain synthesized derivatives, e.g. derivatives 7a, 7c, 7d and 7e exhibited marked inhibitory activity against the test organisms. The compounds having secondary amines exhibit a very good activity against Gram negative and Gram positive bacteria. The compounds substituted with primary amines had low activity against Gram positive and Gram negative bacteria as compared to secondary amines. The secondary amines possessing bulkier alkyl substitution i.e. diisopropyl had better activity. The antifungal screening results were not encouraging or moderate. Compounds showed very less activity against Candida albicans. The structures of the synthesized compounds were established by IR, NMR and Mass Spectroscopy.