Novel N-linked aminopiperidine inhibitors of bacterial topoisomerase type II: broad-spectrum antibacterial agents with reduced hERG activity

J Med Chem. 2011 Nov 24;54(22):7834-47. doi: 10.1021/jm2008826. Epub 2011 Oct 27.

Abstract

Novel non-fluoroquinolone inhibitors of bacterial type II topoisomerases (DNA gyrase and topoisomerase IV) are of interest for the development of new antibacterial agents that are not impacted by target-mediated cross-resistance with fluoroquinolones. Aminopiperidines that have a bicyclic aromatic moiety linked through a carbon to an ethyl bridge, such as 1, generally show potent broad-spectrum antibacterial activity, including quinolone-resistant isolates, but suffer from potent hERG inhibition (IC(50)= 3 μM for 1). We now disclose the finding that new analogues of 1 with an N-linked cyclic amide moiety attached to the ethyl bridge, such as 24m, retain the broad-spectrum antibacterial activity of 1 but show significantly less hERG inhibition (IC(50)= 31 μM for 24m) and higher free fraction than 1. One optimized analogue, compound 24l, showed moderate clearance in the dog and promising efficacy against Staphylococcus aureus in a mouse thigh infection model.

MeSH terms

  • Animals
  • Anti-Bacterial Agents / chemical synthesis*
  • Anti-Bacterial Agents / pharmacokinetics
  • Anti-Bacterial Agents / pharmacology
  • Bacterial Proteins / antagonists & inhibitors*
  • DNA Topoisomerases, Type II / metabolism*
  • Dogs
  • Drug Resistance, Bacterial
  • ERG1 Potassium Channel
  • Ether-A-Go-Go Potassium Channels / antagonists & inhibitors*
  • Gram-Negative Bacteria / drug effects
  • Gram-Positive Bacteria / drug effects
  • Mice
  • Microbial Sensitivity Tests
  • Models, Molecular
  • Piperidines / chemical synthesis*
  • Piperidines / pharmacokinetics
  • Piperidines / pharmacology
  • Protein Conformation
  • Rats
  • Staphylococcal Infections / drug therapy
  • Structure-Activity Relationship
  • Topoisomerase Inhibitors / chemical synthesis*
  • Topoisomerase Inhibitors / pharmacokinetics
  • Topoisomerase Inhibitors / pharmacology

Substances

  • Anti-Bacterial Agents
  • Bacterial Proteins
  • ERG1 Potassium Channel
  • Ether-A-Go-Go Potassium Channels
  • Piperidines
  • Topoisomerase Inhibitors
  • DNA Topoisomerases, Type II