Figure 4.
Hypoxic metabolism of 1b in phosphate-buffered D2O/CD3OD does not lead to incorporation of deuterium into the metabolite 3. LC-MS of the mono-N-oxide metabolite 3 generated by hypoxic metabolism of 1b. Panel A, isotope cluster for the [M+H]+ ion of 3 generated in phosphate-buffered H2O/CH3OH (relative peak intensities for m/z 148:149:150 = 100:7.9:0.5). Panel B, isotope cluster for the [M+H]+ ion of 3 generated in phosphate-buffered D2O/CD3OD (relative peak intensities for m/z 148:149:150 = 100:8.2:0.6).