Laser and Spectroscopy Laboratory, Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
Laser and Spectroscopy Laboratory, Department of Physics, Institute of Science, Banaras Hindu University, Varanasi 221005, India.
Spectrochim Acta A Mol Biomol Spectrosc. 2017 Feb 15;173:307-317. doi: 10.1016/j.saa.2016.09.018. Epub 2016 Sep 19.
A computational investigation of all possible lowest energy conformers of serotonin was carried out at the B3LYP/6-311++G** level. Out of the 14 possible lowest energy conformers, the first 4 conformers were investigated thoroughly for the optimized geometries, fundamental frequencies, the potential energy distributions, APT and natural charges, natural bond orbital (NBO) analysis, MEP, Contour map, total density array, HOMO, LUMO energies. The second third and fourth conformers are energetically at higher temperatures of 78, 94 and 312K respectively with respect to the first one. Bond angles and bond lengths do not show significant variations while the dihedral angles vary significantly in going from one conformer to the other. Some of the vibrational modes of the indole moiety are conformation dependent to some extent whereas most of the normal modes of vibration of amino-ethyl side chain vary significantly in going from one conformer to conformer. The MEP for the four conformers suggested that the sites of the maximum positive and negative ESP change on changing the conformation. The charges at some atomic sites also change significantly from conformer to conformer.
采用 B3LYP/6-311++G** 水平对血清素所有可能的最低能量构象进行了计算研究。在 14 种可能的最低能量构象中，对前 4 种构象进行了深入研究，包括优化的几何形状、基本频率、势能分布、APT 和自然电荷、自然键轨道 (NBO) 分析、静电势能图、轮廓图、总密度数组、最高占据轨道 (HOMO) 和最低未占据轨道 (LUMO) 能量。第二、第三和第四个构象的能量分别比第一个构象在 78、94 和 312K 时高。键角和键长没有显著变化，而从一个构象到另一个构象，二面角变化显著。吲哚部分的一些振动模式在某种程度上与构象有关，而氨基乙基侧链的大多数振动模式在从一个构象到另一个构象时变化显著。四个构象的静电势能图表明，最大正和负静电势能的位置随构象的变化而变化。一些原子位置的电荷也从构象到构象发生显著变化。
