%0 Journal Article %T Chemical Synthesis, 17¦Â-Hydroxysteroid Dehydrogenase Type 1 Inhibitory Activity and Assessment of In Vitro and In Vivo Estrogenic Activities of Estradiol Derivatives %A In VitroIn VivoFran ois Rouillard %A Julie Lefebvre %A Michelle-Audrey FournierDonald Poirier %J The Open Enzyme Inhibition Journal %D 2008 %I %R 10.2174/1874940200801010061] %X 17¦Â-hydroxysteroid dehydrogenase type 1 (17¦Â-HSD1) was chosen as a key steroidogenic target enzyme to reduce the formation of estradiol (E2), which is the most potent estrogen. This article completes a previous study by synthesizing and testing 16¦Â-methylene derivatives (Br, Cl and OH) of E2 in order to generate new structure-activity relationships. This study also investigates a series of 2-methoxy (MeO) derivatives synthesized as non-estrogenic inhibitors of 17¦Â-HSD1. The 2-MeO-E2 derivatives (16¦Â-CH2Br, 16¦Â- CH2OH and 16¦Á-(CH2)3Br) are all less potent inhibitors (IC50 = 5.91, 3.80 and 5.80 ¦ÌM) than analogues without the 2-MeO group (IC50 = 1.20, 1.27 and 0.99 ¦ÌM, respectively) for the reduction of estrone into E2 by 17¦Â-HSD1 overexpressed in HEK-293 cells. Except for one compound, these E2 derivatives have shown an estrogenic-like effect on estrogen-sensitive T-47D cells at 1 ¦ÌM. A cytotoxic effect was also obtained at higher concentrations for two compounds tested on T-47D cells. However, no estrogenic-like effect was observed in the estrogen-sensitive tissues (uterus and vagina) of the ovariectomized mouse model for 2-MeO- 16¦Á-bromopropyl-E2. %U http://www.benthamscience.com/open/toeij/articles/V001/61TOEIJ.htm