Figure 1: Representative Chromatogram of 17-hydroexemestane main metabolite (MIII) extracted from human liver microsomal incubates. Norgestrel was used as an internal standard (IS). The retention times for MIII, 17-hydroexemestane (17-HExe), and norgestrel (IS) were 4.9 min, 12.9 min, and 19.5 min, respectively.