title: Conformational analysis of 19-oxygenated steroids with a 4-ene or 2,4-diene structure, potential intermediates of aromatase reaction, with semiempirical molecular orbital PM3 calculations.
abstract: Conformational analysis of potent competitive inhibitors of aromatase, androst-4-enes 5, as well as 2,4-diene steroids 3, 4, and 6 was carried out, using theoretical calculations, to determine the stereochemistry of their aromatase-catalyzed oxygenation. In the steroids examined, both the 19-alcohols and the 19-aldehydes favor the above- A ring conformation among the possible three in each. The results suggest that the 3-deoxy steroid 5a as well as the 2,4-diene steroids 4a and 6a would be oxygenated at C-19 by aromatase through the same stereomechanism as that involved in the androstenedione aromatization.
mesh_terms: D001141:Aromatase / Q000378:metabolism*; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D008958:Models, Molecular; D008968:Molecular Conformation; D013256:Steroids / Q000737:chemistry* / Q000378:metabolism
chemical_list: D013256:Steroids; D001141:Aromatase