Novel 1-(1-benzyl-1H-indol-3-yl)-N,N,N-trimethylmethanaminium iodides are competitive antagonists for the human α4β2 and α7 nicotinic acetylcholine receptors
作者:Edwin G. Pérez、Cristian Ocampo、Dominik Feuerbach、Jhon J. López、Guibeth L. Morelo、Ricardo A. Tapia、Hugo R. Arias
DOI:10.1039/c3md00042g
日期:——
This work presents the synthesis and the pharmacological characterization of a series of novel 1-(1-benzyl-1H-indol-3-yl)-N,N,N-trimethylmethanaminium iodide derivatives at the human (h) α7 and α4β2 nicotinic acetylcholine receptors (nAChRs). The inhibitory activity of the compounds was determined by Ca2+ influx assays on cells expressing either the hα7 or hα4β2 nAChR subtype. To determine whether the observed inhibitory activity is mediated by a competitive or non-competitive mechanism, additional radioligand binding assays were performed using [3H]methyllycaconitine, [3H]cytisine, and [3H]imipramine. The results established that the compounds inhibit the nAChRs by a competitive mechanism and that the potencies are higher for the hα7 nAChR compared to that for the hα4β2 nAChR. Substitutions with oxygenated functional groups on the benzene ring increase the receptor selectivity. In particular, the hydroxyl derivatives 4b and 4c present the highest selectivity for the hα7 nAChR subtype. Molecular docking results indicate that the hydroxyl group forms a hydrogen bond with the carbonyl group at α7-Gln116, but not at β2-Phe115, supporting the observed receptor selectivity at the molecular level.
本研究介绍了一系列新型 1-(1-苄基-1H-吲哚-3-基)-N,N,N-三甲基甲铵碘化物衍生物在人类(h)δ±7 和 δ±4δ²2烟碱乙酰胆碱受体(nAChRs)上的合成和药理学特征。这些化合物的抑制活性是通过对表达 hα7 或 hα4β2 nAChR 亚型的细胞进行 Ca2+ 流入试验确定的。为了确定所观察到的抑制活性是由竞争性机制还是非竞争性机制介导的,还使用 [3H]methyllycaconitine、[3H]cytisine 和 [3H]imipramine 进行了额外的放射性配体结合试验。结果表明,这些化合物通过竞争机制抑制了 nAChRs,而且与 hα4β2 nAChR 相比,它们对 hα7 nAChR 的抑制作用更强。苯环上含氧官能团的取代增加了受体的选择性。特别是羟基衍生物 4b 和 4c 对 hδ7 nAChR 亚型的选择性最高。分子对接结果表明,羟基与δ±7-Gln116 处的羰基形成了氢键,而与δ²2-Phe115 处的羰基没有形成氢键,这在分子水平上支持了观察到的受体选择性。