Evaluation of Biological Activities of Quinone-4-oxoquinoline Derivatives against Pathogens of Clinical Importance

Background: Microbial resistance has become a worldwide public health problem and may lead to morbidity and mortality in affected patients. Objectives: Therefore, this work aimed to evaluate the antibacterial activity of quinone-4-oxoquinoline derivatives. Methods: These derivatives were evaluated against Gram-positive and Gram-negative bacteria by their antibacterial activity, anti-biofilm, and hemolytic activities and in silico assays. Results: The quinone-4-oxoquinoline derivatives presented broad-spectrum antibacterial activities and, in some cases, were more active than commercially available reference drugs. These compounds also inhibited bacterial adhesion, and the assays revealed seven non-hemolytic derivatives. The derivatives seem to cause damage to the bacterial cell membrane, and those containing the carboxyl group at the C-3 position of the 4-quinolonic nucleus were more active than those containing a carboxyethyl group. Conclusion: The isoquinoline-5,8-dione nucleus also favored antimicrobial activity. The study showed that the target of the derivatives must be a non-conventional hydrophobic allosteric binding pocket on the DNA gyrase enzyme.

Automated summary

This study evaluated the antibacterial activity of quinone-4-oxoquinoline derivatives and found that they exhibited broad-spectrum antibacterial activity, and in some cases were more effective than reference drugs. Additionally, these derivatives inhibited bacterial adhesion and some did not cause hemolysis. The study also suggested that the target of these derivatives may be a non-conventional hydrophobic allosteric binding pocket on the DNA gyrase enzyme.