Screening for Glutathione Conjugates

SCHEME 11.8 Characteristic fragment ions of glutathione conjugates under collision-induced dissociation. Adapted from Ma and Subramanian (2006) with permission of John Wiley and Sons Limited. 

SCHEME 11.9 Bioactivation of acetaminophen to form a reactive A-acetyl-p-benzoquinone imine (NAPQI) and trapping of the electrophilic intermediate by GSH. 

FIGURE 11.8 Collision induced product ion spectra of natural (a, m/z 457) and isotope-labeled GSH adduct (b, m/z 460). Reprinted from Yan et al. (2004) with permission of the American Chemical Society. 

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Neutral-loss and precursor-ion analysis modes are regularly apphed in combination with LC-MS for the detection and/or characterization of Phase-II metabolites [44, 71, 73-74]. Accurate-mass neutral-loss analysis on a Q-TOF instrament was apphed to screen for glutathione conjugates [74]. 

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