2-Heptyl-4-hydroxyquinoline N-oxide, an antistaphylococcal agent produced by Pseudomonas aeruginosa

J Antimicrob Chemother. 1992 Nov;30(5):615-23. doi: 10.1093/jac/30.5.615.


Clinical isolates of Pseudomonas aeruginosa produce low molecular weight, hydrophobic substances which inhibit the growth of Staphylococcus aureus and other Gram-positive organisms. The active substances have been purified from a culture of P. aeruginosa and characterized as a mixture of 2-heptyl-4-hydroxyquinoline N-oxide and its homologues. The alkyl-hydroxyquinolines (derived through reduction of the N-oxide) were also produced by P. aeruginosa cultures but, in general, were less active against S. aureus. 2-Heptyl-4-hydroxyquinoline was identified in a sample of human bronchial secretions from a patient with cystic fibrosis who was heavily colonized with P. aeruginosa. Production of antibacterial alkyl-hydroxyquinoline N-oxides in human lung may explain the observation that the presence of P. aeruginosa in the sputum of patients with cystic fibrosis is correlated with the absence of S. aureus.

MeSH terms

  • Chromatography, High Pressure Liquid
  • Humans
  • Hydroxyquinolines / analysis*
  • Hydroxyquinolines / chemistry
  • Hydroxyquinolines / pharmacology
  • Pseudomonas aeruginosa / metabolism*
  • Staphylococcus / drug effects*


  • Hydroxyquinolines
  • 2-(n-heptyl)-4-hydroxyquinoline N-oxide