Glutathione is the major nonprotein sulfhydryl present in cells and plays an important role in the deactivation of oxygen radicals, organic hydroperoxides and electrophiles. However, recent studies show that conjugation of glutathione with some vicinal dihaloalkanes,haloalkenes. quinoid compounds, isocyanates,isothiocyanates aldehydes, α, β-unsaturated aldehydes etc, will lead to the formation of toxic metabolites.