Discovery of natural estrogen receptor modulators with structure-based virtual screening

Eleven compounds were identified as estrogen receptor modulators from an in-house natural product database (NPD) by structure-based virtual screening for ER alpha and ER beta. Among them, 3 compounds were confirmed as ER agonists and 8 compounds were confirmed as ER antagonists by yeast two-hybrid (Y2H) assay, with EC50 values ranging from several micromolar to 100 micromolar. In this study, a novel series of cycloartane triterpenoids isolated from Schisandra glaucescens Diels was found to have ER antagonistic effect, the most potent antagonist of which exhibited activity with EC50 value of 2.55 and 4.68 mu M for ERa and ERb, respectively. Moreover, the types of modulation and subtype selectivity were also investigated through molecular docking simulation. (C) 2013 Elsevier Ltd. All rights reserved.