Discovery and Optimization of DNA Gyrase and Topoisomerase IV Inhibitors with Potent Activity against Fluoroquinolone-Resistant Gram-Positive Bacteria.

Herein, we describe the discovery and optimization of a novel series that inhibits bacterial DNA gyrase and topoisomerase IV binding to, and stabilization of, DNA cleavage complexes. Optimization of this series led to the identification of compound , which has potent activity against Gram-positive bacteria, a favorable safety profile, and excellent pharmacokinetic properties. Compound was found to be efficacious against fluoroquinolone-sensitive infection in a mouse thigh model at lower doses than moxifloxacin.

Topoisomerase Inhibitors Addressing Fluoroquinolone Resistance in Gram-Negative Bacteria.

Since their discovery over 5 decades ago, quinolone antibiotics have found enormous success as broad spectrum agents that exert their activity through dual inhibition of bacterial DNA gyrase and topoisomerase IV. Increasing rates of resistance, driven largely by target-based mutations in the GyrA/ParC quinolone resistance determining region, have eroded the utility and threaten the future use of this vital class of antibiotics. Herein we describe the discovery and optimization of a series of 4-(aminomethyl)quinolin-2(1)-ones, exemplified by , that inhibit bacterial DNA gyrase and topoisomerase IV and display potent activity against ciprofloxacin-resistant Gram-negative pathogens.