title: Structure-activity relationships of estrogen derivatives as aromatase inhibitors. Effects of heterocyclic substituents.
abstract: Aromatase, which is responsible for the conversion of androgens to estrogens, is a potential therapeutic target for the selective lowering estrogen level in patients with estrogen-dependent breast cancer. We prepared and tested series of the pyridine- and other heterocyclic ring-containing derivatives of 2- and 4-aminoestrones, estrone, and estradiol, compounds 5, 10, 12 and 15. The isonicotinyl derivatives of 2- and 4-aminoestrone, compounds 5c and 10c, were fairly potent competitive inhibitors of aromatase (K(i), 2.1+/-0.14 and 1.53+/-0.08 microM for 5c and 10c, respectively) and other compounds did not show, to a significant extent, the aromatase inhibitory activity. This result suggests that the isonicotinyl-substituted derivatives 5c and 10c would be accessible to the active site of aromatase.
authors.affiliation: Tohoku Pharmaceutical University, Sendai, Japan. numazawa@tohoku-pharm.ac.jp
authors.forename: Mitsuteru
authors.initials: M
authors.lastname: Numazawa
authors.forename: Sachiko
authors.initials: S
authors.lastname: Komatsu
authors.forename: Takako
authors.initials: T
authors.lastname: Tominaga
authors.forename: Kouwa
authors.initials: K
authors.lastname: Yamashita