publications by P. Lee Ferguson.

Papers Published

  1. Y. L. Cui and R. L. Frey and J. L. Ferry and P. L. Ferguson, 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, Rapid Communications In Mass Spectrometry, vol. 23 no. 8 (April, 2009), pp. 1212 -- 1220 .
    (last updated on 2009/06/25)

    A reversed-phase high-performance liquid chromatography/electrospray tandem mass spectrometry method was developed for the characterization of hydroxyl radical oxidation products of N-hexanoy/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 (30C6-HSL), a highly active quorum-sensing signal, by comparison with a reference standard. Three structural isomers with the same mass as 30C6-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. Copyright (C) 2009 John Wiley & Sons, Ltd.