Metabolism of megestrol acetate by rat adrenal glands in vitro.

Megestrol acetate is metabolized by homogenates of rat adrenal glands to three more polar metabolites Y(2), Y(3) and Y(4). Their structures were investigated by microchemical reactions, paper chromatography, and ultraviolet and infrared spectroscopy. Metabolite Y(3) was identified as 17alpha-acetoxy-11beta-hydroxy-6-methyl-pregna-4,6-diene-3,20-dione, its oxidation product being identical with authentic 17alpha-acetoxy-6-methylpregna-4,6-diene-3,11,20-trione.

Metabolism of megestrol acetate and related progesterone analogues by liver preparations in vitro.

1. The rates of metabolism of megestrol acetate, 17alpha-acetoxy-6alpha-methylprogesterone, 6alpha-methylprogesterone, 17alpha-acetoxyprogesterone and progesterone by liver microsome-supernatant fractions from female rats and rabbits have been compared. 2.