Background: Hospital-acquired (HA) infections are caused due to E. coli, which is resistant
to multiple drugs particularly to fluoroquinolone class of drugs. Urinary tract infections
(UTI) affects people in the community and hospitals. 150 million people per annum are suffering
from UTI worldwide.
Methods: In this present study, we designed 36 novel coumarin derivatives, also we predicted
pharmacokinetic and toxicity parameters. Docking studies were also carried out and all the compounds
were evaluated for antibacterial activity against resistant quinolone E. coli strain ATCC
25922. It was interesting to note that the introduction of electron-withdrawing group on the aromatic
ring resulted in compounds with an increased antibacterial activity, which is observed in
compound 6 (with 4-nitro substitution), compound 23 (chloro) and compound 30 (chloro, nitro).
Results: From the MIC results, it was observed that compounds 6, 23 and 30 showed higher activity
with 0.5μg/ml, 0. 12 μg/ml, 0.5 μg/ml respectively. Docking studies were performed with the
active site of DNA gyrase (PDB ID: 4CKK). The maximum binding energy was found to be -10.7
Conclusion: From the study, it was found that 3 compounds were potentially active against quinolone-
resistant E. coli strains. This study can further be extended for in vivo evaluation.