Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan.
Molecules. 2013 Jan 16;18(1):1122-7. doi: 10.3390/molecules18011122.
Phytoestrogens are defined as plant-derived compounds with estrogen-like activities according to their chemical structures and activities. Plant lignans are generally categorized as phytoestrogens. It was reported that (-)-arctigenin, the aglycone of arctiin, was demethylated to (-)-dihydroxyenterolactone (DHENL) by Eubacterium (E.) sp. ARC-2. Through stepwise demethylation, E. sp. ARC-2 produced six intermediates, three mono-desmethylarctigenins and three di-desmethylarctigenins. In the present study, ligand binding affinities of (-)-arctigenin and its seven metabolites, including DHENL, were investigated for an estrogen receptor alpha, and found that demethylated metabolites had stronger binding affinities than (-)-arctigenin using a ligand binding screen assay method. The IC(50) value of (2R,3R)-2-(4-hydroxy-3-methoxybenzyl)-3-(3,4-dihydroxybenzyl)-butyrolactone was 7.9 × 10⁻⁴ M.
植物雌激素是根据其化学结构和活性定义的具有雌激素样活性的植物源性化合物。植物木脂素通常被归类为植物雌激素。据报道，（-）-刺槐素，刺槐苷的苷元，被细菌（Eubacterium）sp.ARC-2 去甲基化为（-）-二羟基-δ-内酯（DHENL）。通过逐步去甲基化，E. sp.ARC-2 生成了六个中间体，三种单去甲基刺槐素和三种二去甲基刺槐素。在本研究中，使用配体结合筛选测定法研究了（-）-刺槐素及其七种代谢物，包括 DHENL，对雌激素受体 α 的结合亲和力，发现去甲基化代谢物的结合亲和力强于（-）-刺槐素。（2R,3R）-2-（4-羟基-3-甲氧基苄基）-3-（3,4-二羟基苄基）-丁内酯的 IC50 值为 7.9×10⁻⁴ M。
