As a result of the ring-into-ring conversion of nitrosoimidazole derivatives, we obtained a molecular scaffold that, when properly decorated, is able to decrease inotropy by blocking L-type calcium channels. Previously, we used this scaffold to develop a quantitative structure-activity relationship (QSAR) model, and we used the most potent oxadiazolothiazinone as a template for ligand-based virtual screening. Here, we enlarge the diversity of chemical decorations, present the synthesis and in vitro data for 11 new derivatives, and develop a new 3D-QSAR model with recent in silico techniques. We observed a key role played by the oxadiazolone moiety: given the presence of positively charged calcium ions in the transmembrane channel protein, we hypothesize the formation of a ternary complex between the oxadiazolothiazinone, the Ca2+ ion and the protein. We have supported this hypothesis by means of pharmacophore generation and through the docking of the pharmacophore into a homology model of the protein. We also studied with docking experiments the interaction with a homology model of P-glycoprotein, which is inhibited by this series of molecules, and provided further evidence toward the relevance of this scaffold in biological interactions.
由于硝基
咪唑衍
生物的环到环转变,我们获得了一个分子骨架,适当修饰后能够通过阻断L型
钙通道来降低心肌收缩力。先前,我们利用这个骨架开发了一个定量构效关系(Q
SAR)模型,并使用其中效力最强的二唑
硫嗪酮作为基于
配体的虚拟筛选模板。在此,我们扩展了
化学修饰的多样性,提供了11种新衍
生物的合成和体外数据,并且利用最新的计算机技术开发了一个新的三维Q
SAR模型。我们观察到了
二唑酮部分的关键作用:鉴于跨膜通道蛋白中存在带正电的
钙离子,我们假设二唑
硫嗪酮、
钙离子和蛋白质之间形成了三元复合物。通过生成药效团并将其对接进蛋白质的同源模型中,我们支持了这一假设。我们还利用对接实验研究了与P-糖蛋白同源模型的相互作用,这一系列的分子能够抑制P-糖蛋白,并为这个骨架在
生物相互作用中的相关性提供了更多证据。