Identification of hydroxyl radical oxidation products of N-hexanoyl-homoserine lactone by reversed-phase high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.


Journal Article

A reversed-phase high-performance liquid chromatography/electrospray tandem mass spectrometry method was developed for the characterization of hydroxyl radical oxidation products of N-hexanoyl-homoserine lactone (C6-HSL), a member of the N-acylhomoserine lactone (AHL) class of microbial quorum-sensing signaling molecules identified in many Gram-negative strains of bacteria. Six products were identified: four with molecular weight (MW) of 213 and two with MW of 260. The characteristic product ions formed through collision-induced dissociation (CID) provided diagnostic structural information. One of the photolysis products was determined to be N-(3-oxohexanoyl)homoserine lactone (3OC6-HSL), a highly active quorum-sensing signal, by comparison with a reference standard. Three structural isomers with the same mass as 3OC6-HSL were identified as acyl side chain oxidized C6-HSL (keto/enol functionalized) by accurate mass measurement and the structures of these products were proposed from CID spectral interpretation. Two structural isomers formed from concurrent oxidation and nitration of C6-HSL were also observed and their structures were postulated based on CID spectra. In addition to the six hydroxyl radical oxidation products formed from the C6-HSL precursor, five additional compounds generated from combined oxidation and lactonolysis of C6-HSL were identified and structures were postulated.

Full Text

Duke Authors

Cited Authors

  • Cui, Y; Frey, RL; Ferry, JL; Ferguson, PL

Published Date

  • April 2009

Published In

Volume / Issue

  • 23 / 8

Start / End Page

  • 1212 - 1220

PubMed ID

  • 19283787

Pubmed Central ID

  • 19283787

Electronic International Standard Serial Number (EISSN)

  • 1097-0231

International Standard Serial Number (ISSN)

  • 0951-4198

Digital Object Identifier (DOI)

  • 10.1002/rcm.3991


  • eng