A representative group of multicyclic aromatic hydrocarbons (MAHC) which can be further classified as bridged-ring (bridged-MAHC) or fused-ring (fused-MAHC) were examined for their ability to interact with the estrogen receptor of rainbow trout (rtER) in a hepatic cytosolic estrogen receptor competitive binding assay (cyto rtERαβ) and the vitellogenin (Vtg) mRNA gene activation liver slice assay. All five fused-MAHCs; naphthalene (NAFT), fluorene (FE), Fluoranthene (FAT), pyrene (PY), and 9,10-dihydroanthracene (DAC) had no estrogenic activity in the in vitro assays used. Five of the eight bridged-MAHCs; triphenylethylene (3PE), o-terphenyl (OTP), triphenylmethane (TPM), 1,1-diphenylethylene (DPE), and cis-stilbene (CSB) were positive in the rtER-binding assay. The additional three bridged-MAHC’s; trans-stilbene (TSB), tetraphenylethylene (4PE), and 4,4-di-tertbutylphenyl (DtBB) were determined to be non-binders due to isomeric configuration, solubility limitation, and possible steric hinderance. It is possible that the bridged-MAHCs bind to the rtER through a proposed aromatic-aromatic stacking (π-π interaction) facilitated by perpendicular ring orientation achieved through free rotation of the bridged rings. The fused-ring structures are locked in a planar configuration which doesn’t allow for rotation of rings perpendicular to one another. This first report of the rtER-binding of bridged-MAHCs in fish demonstrates binding for a class of chemicals normally not thought of as having an affinity for the estrogen receptor and further supports the versatility or promiscuity of ER ligand selectivity.

研究了一组代表性的多环芳烃（MAHC），它们可以进一步分为桥环（bridged-MAHC）或稠环（fused-MAHC）与虹鳟（rtER）的雌激素受体相互作用的能力在肝细胞溶质雌激素受体竞争结合试验（cytortERαβ）和卵黄蛋白原（Vtg）mRNA基因激活肝切片试验中进行了研究。所有五个熔融MAHC；萘（NAFT），芴（FE），荧蒽（FAT），pyr（PY）和9,10-二氢蒽（DAC）在体外没有雌激素活性使用的测定法。八个桥接的MAHC中的五个；在rtER结合试验中，三苯乙烯（3PE），邻三苯（OTP），三苯甲烷（TPM），1,1-二苯乙烯（DPE）和顺二苯乙烯（CSB）呈阳性。另外三个桥接的MAHC；由于同分异构构型，溶解度限制和可能的空间位阻，反式二苯乙烯（TSB），四苯乙烯（4PE）和4,4-二叔丁基苯基（DtBB）被确定为非粘合剂。桥接的MAHC可能通过拟议的芳香族-芳香族堆积（π-π相互作用）与rtER结合，而芳香族-芳香族堆积是通过桥接环的自由旋转实现的垂直环取向而实现的。稠环结构被锁定在一种平面结构中，该结构不允许环彼此垂直旋转。