Fig. 2.

LC-MS analysis of the GSHEE adduct formed by incubation of tamoxifen with CYP2B6 in the presence of NADPH. CYP2B6 was reconstituted with reductase and incubated with tamoxifen and GHSEE. The separation and analysis of the adduct are as described under Materials and Methods. A, the extracted ion chromatogram for the hydroxytamoxifen quinone methide adduct with m/z 719. B, the MS² of the peak eluting at 18.3 min with an m/z 719. C, the primary sites of fragmentation of the tamoxifen-GSHEE adduct.