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采用量子化学密度泛函理论和极化连续介质模型在B3LYP/6-311++G"水平上时DEHP、MEHP、DBP、MBP和雌二醇在水溶液中的电子结构特征进行了理论研究,获得了上述化合物的几何构型、表现静电势、前线轨道等信息;采用电子密度拓扑分析方法分析获得了分子中的键鞍点电荷密度.在此基础上,对分子电子结构与生物活性的关系进行了初步探讨.结果表明,MBP、MEHP分子表观正、负电势程度比DBP、DEHP大,有利于与受体形成稳定的复合物;MBP、MEHP的△E_(gap)分别比DBP、DEHP更小,反应活性更高;MBP、MEHP的分子偶极矩比DBP、DEHP相应提高了22%、34%,有利于与受体分子之间的氢键相互作用、偶极-偶极相互作用.以上研究结果验证了MBP、MEHP毒性分别高于DBP、DEHP的实验结论.研究还发现,邻苯二甲酸酯类塑化剂与雌二醇在电子结构特征上存在较大差异,该类化合物可能具有与雌二醇不同的受体或结合位点.
The electronic structures of DEHP, MEHP, DBP, MBP and estradiol in aqueous solution have been studied theoretically by means of quantum chemical density functional theory and polarization continuum model at B3LYP / 6-311 ++ G level. The geometrical configurations of these compounds were obtained, and electrostatic potential and frontier orbitals were obtained. The charge-saddle point charge density in the molecule was obtained by topological analysis of electron density. On the basis of this, the relationship between molecular electronic structure and biological activity The results showed that the apparent positive and negative potentials of MBP and MEHP molecules were greater than that of DBP and DEHP, which was in favor of the formation of a stable complex with the receptors. The △ E gaps of MBP and MEHP were respectively more than those of DBP and DEHP The molecular dipole moment of MBP and MEHP is 22% and 34% higher than that of DBP and DEHP respectively, which is in favor of the hydrogen bond interaction with the acceptor molecule and the dipole-dipole interaction. The above results verify that the toxicity of MBP and MEHP are higher than the experimental conclusion of DBP and DEHP respectively.The study also found that the electronic structure characteristics of phthalate plasticizers and estradiol are quite different, Has a different receptor with estradiol Body or binding site.