1 / 16

M. Triquigneaux, B. Tuccio, R. Lauricella et L. Charles

EPR/MS combination: Mechanism elucidation applied to thiol compounds. M. Triquigneaux, B. Tuccio, R. Lauricella et L. Charles Laboratoire Chimie Provence, UMR 6264, Equipe Spectrométries Appliquées à la Chimie Structurale, Campus de St Jérôme, 13397 Marseille cedex 20. EPR/MS Combination.

leora
Download Presentation

M. Triquigneaux, B. Tuccio, R. Lauricella et L. Charles

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. EPR/MS combination: Mechanism elucidation applied to thiol compounds M. Triquigneaux, B. Tuccio, R. Lauricella et L. Charles Laboratoire Chimie Provence, UMR 6264, Equipe Spectrométries Appliquées à la Chimie Structurale, Campus de St Jérôme, 13397 Marseille cedex 20.

  2. EPR/MS Combination Electronic Paramagnetic Resonance Nitroxide Specificity  paramagnetic species only Sensitivity  concentration 10-7-10-8 mol/L Structure  g factor, hyperfine coupling constants… 1

  3. EPR/MS Combination aH aN aN~ 15.5 G aH ~ 1.8 G How to access the global structure of nitroxide ? 2

  4. EPR/MS Combination Mass spectrometry H+ H+ Nitroxide Oxoammonium Hydroxylamine m/z m/z – 1 m/z + 1 Tuccio B., Lauricella R., Charles L., Int. J. Mass Spec., 252 (2006), 47-53. El Hassan I., Charles L., Lauricella R., Tuccio B., New J. Chem., 32 (2008), 680-688. Detection of nitroxide radical species Detection of derived redox species 3

  5. Aim of the study: reactivity of glutathione toward MNP Glutathione S-transferase MNP MNP R. xenobiotics physiological substrate ? toxic by-products antioxidant 4

  6. EPR Study S-adduct aN = 18.2 G Experimental conditions 1) Glutathione MNP 2) Oxidant 5

  7. EPR Study O-adduct aN = 27.1 G Experimental conditions 1) Glutathione MNP Oxidant 2) Photo-irradiation 6

  8. MS Study ESI-MS in negative mode S-adduct m/z 393.1 m/z 407.1 O-adduct No Detection of S- and O-adducts as nitroxides Detection of derived redox species m/z 409.1 7

  9. MS/MS Study S-adduct ESI-MS/MS in negative mode 272.1 Glutathione product ions 393.1 25 eV 143.1 128.1 254.1 210.1 393.1 179.1 m/z 8 Dieckhaus C., Fernandez-Metzler C., King R., Krolikowski P., Baillie T., Chem. Res. Toxicol., 18 (2005), 630-638.

  10. MS/MS Study O-adduct ESI-MS/MS in negative mode 272.1 409.1 Glutathione product ions 20 eV 409.1 304.1 254.1 143.1 321.1 128.1 179.1 210.1 m/z 9

  11. MS/MS Study m/z 409.1 m/z 321.1 m/z 409.1 m/z 304.1 10

  12. MS/MS Study Methylated product of S-adduct ESI-MS/MS in negative mode Glutathione product ions 128 254 143 m/z 407.1 m/z 272.1 11

  13. Mechanism elucidation Forrester-Hepburn oxidation -NO + NuH -N(OH)-Nu -N(O.)-Nu Inverted spin trapping oxidation hν NuH -NO -.+NO -N(O.)-Nu Detection of reaction intermediates Distinct experimental conditions 12

  14. Mechanism elucidation S-adduct Forrester-Hepburn RPE MS O-adduct Inverted spin trapping 13

  15. Conclusion MNP/GSH/oxidant Stable S-adduct New O-adduct Derivatization methylated product Detailed reactivity of glutathione toward MNP EPR/MS Structural characterization Mechanism elucidation Efficient method for radical study 14

  16. Acknowledgments Organization committee SMAP 2009 Provence University, Laboratory LCP, Marseille SACS team Spectropole FEDER OBJ2142-3341

More Related