Pure Appl. Chem., 2003, Vol. 75, No. 9, pp. 1197-1205
doi:10.1351/pac200375091197
Boron clusters for medicinal drug design: Selective estrogen receptor modulators bearing carborane*
Yasuyuki Endo, Tomohiro Yoshimi, and Chisato Miyaura
1Tohoku Pharmaceutical University, Sendai 981-8558, Japan; 2Tokyo University of Pharmacy and Life Science, Hachioji, Tokyo 192-0392, Japan
Abstract:
The molecular shape and hydrophobicity of dicarba-closo -dodecaboranes may allow a new medical application as biologically active molecules. Recently, we have developed potent estrogen receptor (ER) agonists bearing carborane cage. The most potent compound (BE120) exhibited activity at least several times greater than that of 17 beta-estradiol in luciferase reporter gene assay and ER alpha binding. We also designed and synthesized estrogen antagonists on the basis of the structure of BE120, and we noticed the characteristic features of compound (BE360) having carborane cage and two phenols. The ER binding affinity of BE360 is comparable to that of estradiol. To examine in vivo estrogenic activity of the compound in bone, ovariectomized (OVX) mice were given BE360 or estradiol subcutaneously for 4 weeks. Treatment with BE360 at 1–30 µg/day dose-dependently restored bone loss in OVX mice to sham level without estrogenic action in uterus. These results suggest its possible application to osteoporosis as a new type of selective ER modulator.
*Lecture presented at the XIth International Meeting on Boron Chemistry (IMEBORON XI), Moscow, Russia, 28 July - 2 August 2002. Other presentations are published in this issue, pp. 1157-1355.