14alpha-Hydroxyoestrone, a new oestrogen metabolite.

1. Incubation of oestrone with ox adrenal glands leads to the formation of two main metabolites, one of which has recently been identified as 15alpha-hydroxyoestrone; the second metabolite (Oe-5) has now been obtained in crystalline form and identified as the hitherto unknown 14alpha-hydroxyoestrone. 2. The identity of compound Oe-5 with 14alpha-hydroxyoestrone was confirmed conclusively by comparison with 14alpha-hydroxyoestrone that was synthesized by pyrolytic aromatization of 14alpha-hydroxyandrosta-1,4-diene-3,17-dione. 3. The physical and chemical properties as well as the oestrogenic activity of 14alpha-hydroxyoestrone are described. 4. The biogenesis and metabolism of 14alpha-hydroxyoestrone were studied in various tissue preparations.