葛根素与水二聚体相互作用的密度泛函理论研究

Density Function Theory on Intermolecular Interactions of Puerarin-water Dimers

采用DET-B3LYP/6-31+G方法优化了葛根素与水的二聚体几何结构和电子结构,计算二聚体的几何构型,电荷分布及转移,结合能和热力学性质。探讨葛根素与水分子之间相互作用的结构及能量变化,旨在密度泛函理论上寻找其最稳定结构。结果显示,与单体相比,各二聚体在接触点上的氧原子,氢原子及附近的氧原子变化明显,两子体系间的电荷转移较多。二聚体(Ⅰ～Ⅵ)中的接触点(O-H…O)距离最小为0.158 0 nm,最大的结合能和焓变值分别为79.82 kJ·mol^(-1)和-20.92 kJ·mol^(-1)均属于构型Ⅲ。即葛根素与水相互作用形成二聚体(Ⅰ～Ⅵ)中,二聚体Ⅲ为最稳定结构。

The optimized geometries and electronic structures of puerarin, water and their possible stable dimers were obtained at the DFT-B3LYP/6-31+G level. Structures, thermodynamics, energy and charge were also measured. To investigate the change to the structure and energy between puerarin and water molecules as well as its optimal structure by density functional theory. Compared with the monomer, charge redistribution mainly occurred on the adjacent O-H…O atoms of puerarin dimers between submolecules while the change of the charge between two submolecules was large for all two Puerarin-water Dimers. In addition, the minimum distances of the connection point(O-H…O) in Dimers(Ⅰ~Ⅵ) that belong to the dimer Ⅲ reached 0.1580 nm. The maximum corrected binding energy and enthalpy of Puerarin-water Dimers that also belong to the dimer Ⅲreached 79.82 kJ·mol^-1 ,-20.92 kJ·mol^-1 . The DimerⅢ is the most stable in the constitution of Puerarin-water Dimers(Ⅰ~Ⅵ).