Antimicrobial Properties of Newly Synthesized Derivatives of Coumarine

Problem statement: Coumarins are well known for their biological activity. On the basis of that we have synthesized some new derivatives of coumarine and investigated their antimicrobial properties. Approach: 4-Heteroaryl-coumarin-3-carbaldehydes 4(a-d) are synthesized by condensation of 4-chloro-coumarin-3-carbaldehydes 2 and corresponding heterorylamines 3(a-d) under reflux reaction conditions. Antimicrobial properties of new coumarins 4(a-d) are investigated and results are submitted for their activities against Staphylococcus aureus, Escherichia coli, Hafnia alvei, Pseudomonas aeruginosa and Enterobacter cloacae. Applying the Agar disc diffusion technique we measured diameters of the inhibition zone around discs which are previously wetted with N, N-DMF solution of compounds, 1, 3 and 5 mg L⁻¹. Results: The inhibition zone depends from concentrations and also from sort of bacteria. The inhibition zone differ from 0 to 30mm. Two sort of bacteria, Hafnia alvei and Pseudomonas aeruginosa, are resistant to these new synthesized compounds. Conclusion: From results we may conclude that these derivates showed moderate to high activity against Staphylococcus aureus, Escherichia coli and Enterobacter cloaco. Compounds 4(a-d) are more active against Staphylococcus aureus, E.coli and Enterobacter cloaco. Compounds 4(a-d) are not active against Hafnia alvei and Pseudomonas aeruginosa.