Synthesis of new coumarin derivatives and assessment of their antimicrobial efficacy.

AIM

Developing new antimicrobial agents in response to the urgent challenge of antimicrobial resistance.

METHODS

Synthesis of the targeted coumarins, elucidation of their structures using spectroscopic tools, and investigation of their antimicrobial activity.

RESULTS

Coumarin-pyrazole with CF in the 3-position of the pyrazole ring displayed the lowest minimum inhibitory concentrations (MICs) and the minimum bactericidal concentrations (MBCs) with values of 1.95 and 15.6 µg/ml, respectively, against . In addition, it exhibited the best inhibitory activity against (MIC = 3.91 µg/ml) compared to the rest of the derivatives (7.81-62.5 µg/ml). Surprisingly, coumarin with the S-CH group had higher ability to inhibit the strain with an MIC value of , which is twice that of penicillin G (). At the same time, compounds , , , , and penicillin G showed similar activity with an MIC value of against . Also, the lowest MIC value (3.91 µg/ml) was obtained for S-CH derivative against . Coumarins and 1,3,4-thiadiazine derivative recorded the lowest MBC (15.6 µg/ml) against .

CONCLUSION

Finally, it can be concluded that some designed coumarins have a high potential to act as potent antimicrobial agents. Some of them displayed higher efficacy than or equal to the reference drug.