Electrospray/mass spectrometric identification and analysis of 4-hydroxy-2-alkylquinolines (HAQs) produced by Pseudomonas aeruginosa

  • François Lépine
  • Sylvain Milot
  • Eric Déziel
  • Jianxin He
  • Laurence G. Rahme
Article

DOI: 10.1016/j.jasms.2004.02.012

Cite this article as:
Lépine, F., Milot, S., Déziel, E. et al. J Am Soc Mass Spectrom (2004) 15: 862. doi:10.1016/j.jasms.2004.02.012

Abstract

The opportunistic pathogen Pseudomonas aeruginosa produces a large array of 4-hydroxy-2-alkylquinolines (HAQs). These compounds were analyzed by LC/MS, using positive electrospray ionization, in the culture supernatant of strain PA14. Fifty-six HAQs and related compounds were detected and their [M+H]+ ions were further analyzed by collision induced dissociation (CID). These HAQs were grouped into five different series based on the presence of an hydrogen or hydroxyl group at the 3 position, an N-oxide group in place of the quinoline nitrogen, and an unsaturation on their alkyl side chain. Two new analogs of 3,4-dihydroxy-2 heptylquinoline, the Pseudomonas quinolone signal (PQS), were found with an alkyl chain longer by one and two methylene groups. Moreover, two additional series of compounds were identified in which a saturated or unsaturated alkyl side chain is located at the 3 position along with an hydroxyl group at the 3 position and a ketone at the 2 position. No HAQ N-oxides, nor any compounds from the latter two series, were detected in a pqsL mutant derivative of PA14, indicating that this gene is involved in the biosynthesis of these compounds. This work demonstrates the large repertoire of HAQ and HAQ-related compounds produced by P. aeruginosa, and provides insight into N-oxides biosynthesis and confirm the hypothesis that N-oxides are the precursors of compounds from Series 6 and 7.

Copyright information

© American Society for Mass Spectrometry 2004

Authors and Affiliations

  • François Lépine
    • 1
  • Sylvain Milot
    • 1
  • Eric Déziel
    • 2
  • Jianxin He
    • 2
  • Laurence G. Rahme
    • 2
  1. 1.INRS-Institut Armand-FrappierUniversité du QuébecLavalCanada
  2. 2.Department of Surgery, Harvard Medical School and Shriner’s Burns InstituteMassachusetts General HospitalBostonUSA

Personalised recommendations