Benzothieno[3,2-b]indole Derivatives as Potent Selective Estrogen Receptor Modulators.

Abstract—A series of estrogen receptor ligands based on benzothieno[3,2-b]indole were synthesized and their binding affinity forestrogen receptor subtypes (ERa and ERb) and effects on mouse uterus and bone were evaluated. Some of these compounds showedstrong binding affinity to ER and significantly increased the bone mineral density of ovariectomized mice. 2005 Elsevier Ltd. All rights reserved. Estrogen receptor and endogenous estrogens playimportant roles in the development and function of fe-male reproductive system. At present, estrogen replace-ment therapy (ERT) is one of the most effectivetreatments for menopausal symptoms and postmeno-pausal osteoporosis arising from lowering levels of cir-culation estrogen. 1 Although ERT is effective, it is alsoassociated with some serious side-effects. More recently,selective estrogen receptor modulators (SERMs) whichfully antagonize the effects of estrogen on uterine andmammary tissues, while mimicking the effects of estro-gen on the bone and cardiovascular system, have beeninvestigated as a possible alternative to ERT.