Discovery and Optimization of Indolyl-Containing 4-Hydroxy-2-Pyridone Type II DNA Topoisomerase Inhibitors Active against Multidrug Resistant Gram-negative Bacteria

J Med Chem. 2018 May 24;61(10):4456-4475. doi: 10.1021/acs.jmedchem.8b00114. Epub 2018 May 14.

Abstract

There exists an urgent medical need to identify new chemical entities (NCEs) targeting multidrug resistant (MDR) bacterial infections, particularly those caused by Gram-negative pathogens. 4-Hydroxy-2-pyridones represent a novel class of nonfluoroquinolone inhibitors of bacterial type II topoisomerases active against MDR Gram-negative bacteria. Herein, we report on the discovery and structure-activity relationships of a series of fused indolyl-containing 4-hydroxy-2-pyridones with improved in vitro antibacterial activity against fluoroquinolone resistant strains. Compounds 6o and 6v are representative of this class, targeting both bacterial DNA gyrase and topoisomerase IV (Topo IV). In an abbreviated susceptibility screen, compounds 6o and 6v showed improved MIC90 values against Escherichia coli (0.5-1 μg/mL) and Acinetobacter baumannii (8-16 μg/mL) compared to the precursor compounds. In a murine septicemia model, both compounds showed complete protection in mice infected with a lethal dose of E. coli.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Anti-Bacterial Agents / chemistry
  • Anti-Bacterial Agents / pharmacology*
  • DNA Topoisomerases, Type II / chemistry*
  • Drug Discovery*
  • Drug Resistance, Multiple, Bacterial / drug effects*
  • Female
  • Gram-Negative Bacteria / drug effects*
  • Mice
  • Microbial Sensitivity Tests
  • Models, Molecular
  • Molecular Structure
  • Protein Conformation
  • Pyridines / chemistry
  • Sepsis / drug therapy*
  • Sepsis / microbiology
  • Structure-Activity Relationship
  • Topoisomerase II Inhibitors / chemistry
  • Topoisomerase II Inhibitors / pharmacology*

Substances

  • Anti-Bacterial Agents
  • Pyridines
  • Topoisomerase II Inhibitors
  • DNA Topoisomerases, Type II