Novel substituted (pyridin-3-yl)phenyloxazolidinones: antibacterial agents with reduced activity against monoamine oxidase A and increased solubility

J Med Chem. 2007 Oct 4;50(20):4868-81. doi: 10.1021/jm070428+. Epub 2007 Aug 28.

Abstract

Oxazolidinones represent a new and promising class of antibacterial agents. Current research in this area is mainly concentrated on improving the safety profile and the antibacterial spectrum. Oxazolidinones bearing a (pyridin-3-yl)phenyl moiety (e.g., 3) generally show improved antibacterial activity compared to linezolid but suffer from potent monoamine oxidase A (MAO-A) inhibition and low solubility. We now disclose the finding that new analogues of 3 with acyclic substituents on the pyridyl moiety exhibit excellent activity against Gram-positive pathogens, including linezolid-resistant Streptococcus pneumoniae. Generally, more bulky substituents yielded significantly reduced MAO-A inhibition relative to the unsubstituted compound 3. The MAO-A SAR can be rationalized on the basis of docking studies using a MAO-A/MAO-B homology model. Solubility was enhanced with incorporation of polar groups. One optimized analogue, compound 13, showed low clearance in the rat and efficacy against S. pneumoniae in a mouse pneumonia model.

MeSH terms

  • Acetamides / pharmacology
  • Animals
  • Anti-Bacterial Agents / chemical synthesis*
  • Anti-Bacterial Agents / pharmacokinetics
  • Anti-Bacterial Agents / pharmacology
  • Dogs
  • Drug Resistance, Bacterial
  • Gram-Positive Bacteria / drug effects*
  • Humans
  • Linezolid
  • Mice
  • Microbial Sensitivity Tests
  • Microsomes, Liver / metabolism
  • Models, Molecular
  • Monoamine Oxidase / chemistry
  • Monoamine Oxidase / metabolism*
  • Oxazolidinones / chemical synthesis*
  • Oxazolidinones / pharmacokinetics
  • Oxazolidinones / pharmacology
  • Pneumonia, Pneumococcal / drug therapy
  • Pyridines / chemical synthesis*
  • Pyridines / pharmacokinetics
  • Pyridines / pharmacology
  • Rats
  • Rats, Wistar
  • Solubility
  • Streptococcus pneumoniae / drug effects
  • Structure-Activity Relationship

Substances

  • Acetamides
  • Anti-Bacterial Agents
  • Oxazolidinones
  • Pyridines
  • Monoamine Oxidase
  • Linezolid