11α-Hydroxy Testosterone, a testosterone metabolite, is synthesized by the cytochrome P450 (CYP) isoform CYP3A.1, and can alternatively be produced from testosterone by a CYP107A1 mutant or from 11α-hydroxy progesterone by the fungus B. bassiana.2,3 The biological activity of 11α-Hydroxy Testosterone remains unclear.
6',7'-Dihydroxybergamottin is a potent inhibitor of CYP3Aactivity, and may be primarily responsible for the effects of grapefruit juice on cytochrome P450 activity in humans.