Estrogenic antagonists bearing dicarba-closo-dodecaborane as a hydrophobic pharmacophore

Dicarba-closo-dodecaboranes (carboranes), which have spherical geometry and hydrophobicity, are applicable as a hydrophobic pharmacophore of biologically active molecules. We have designed and synthesized estrogenic antagonists based on the structure of the potent agonist 1-hydroxymethyl-12-(4-hydroxyphenyl)-1,12-dicarba-closo-dodecaborane, which we have developed. The compounds showed potent antagonistic activity in luciferase reporter gene assay using COS-1 cells transfected with rat ERα-expression plasmid and an appropriate reporter plasmid.