LC-MS/MS analysis of the RU486-GSH conjugates G769 and G751 formed by liver
microsomes from PB-treated rats. A, extracted ion chromatograms at
m/z 769 and 751. B, MS/MS spectra of G769 and G751 eluting
at 11.8 and 12.2 min, respectively. C, right, proposed structures of G769 and
G751. Dashed lines, sites of fragmentation as described in the text.