Structure-activity relationships of some unique estrogens related to estradiol are predicted by fit into DNA.

The estrogenic activity of 11 beta-acetoxy estradiol, 11 beta-hydroxy estradiol, 11 alpha-hydroxy estradiol and 9 beta-estradiol was compared to estradiol using the restoration of uterine weight and prevention of LH rise in immature ovariectomized rats as endpoints of the assay. There was a good correlation between results using the two methods and estrogenic activity was found to be in the following order: 11 beta-acetoxy estradiol greater than estradiol greater than 9 beta-estradiol greater than 11 beta-hydroxy estradiol greater than 11 alpha-hydroxy estradiol. The biological activities of these compounds could be explained on the basis of stereochemical complementarity to the structure of DNA.