Aqueous-Phase Conformations of Lactose, Maltose, and Sucrose and the Assessment of Low-Cost DFT Methods with the DSCONF Set of Conformers for the Three Disaccharides.,The Journal of Physical Chemistry A

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Aqueous-Phase Conformations of Lactose, Maltose, and Sucrose and the Assessment of Low-Cost DFT Methods with the DSCONF Set of Conformers for the Three Disaccharides.
The Journal of Physical Chemistry A ( IF 2.7 ) Pub Date : 2020-01-13 , DOI: 10.1021/acs.jpca.9b10932
Bun Chan ₁

Affiliation

In the present study, we have examined a range of quantum chemistry methods for the calculation of conformers for lactose, maltose, and sucrose. We find that the DSD-PBE-P86/aug'-cc-pVTZ//B3-LYP-D3BJ/6-311+G(2d,p) protocol yields good relative energies in comparison with reference CCSD(T)/CBS//B3-LYP-D3BJ/maug-cc-pVTZ values. We have surveyed a total of ∼550 conformers for the three disaccharides with the chosen DSD-PBE-P86 method in conjunction with continuum aqueous solvation. In each case, the lowest free energy conformer is characterized by hydrogen bond(s) between the two rings. Another finding is that the major contributors to the overall variations in aqueous free energies are the electronic energies and the solvation energies. To facilitate investigations of larger systems, we have compiled the DSCONF set of conformers for the three disaccharides, and we have assessed lower cost methods with this set. We find MS1-D3/6-31+G(2d,p) to be cost-effective and accurate for both geometry optimization and the calculation of relative energies for disaccharides. In addition, we note that MS1-D3 has previously been found to yield good relative energies for the WATER27 set of water clusters. We thus deem this method to be appropriate for the study of saccharide conformations in both gas phase and aqueous solution.

中文翻译：

乳糖，麦芽糖和蔗糖的水相构象，以及使用DSCONF构象异构体对三种二糖的低成本DFT方法的评估。

在本研究中，我们检查了一系列量子化学方法，用于计算乳糖，麦芽糖和蔗糖的构象异构体。我们发现，与参考CCSD（T）/ CBS /相比，DSD-PBE-P86 / aug'-cc-pVTZ // B3-LYP-D3BJ / 6-311 + G（2d，p）协议可产生良好的相对能量/ B3-LYP-D3BJ / maug-cc-pVTZ值。我们使用所选的DSD-PBE-P86方法结合连续水溶溶剂，对这三种二糖的总共550个构象异构体进行了调查。在每种情况下，最低的自由能构象物的特征是两个环之间的氢键。另一个发现是，水自由能总体变化的主要贡献者是电子能和溶剂化能。为了便于调查大型系统，我们已经为这三种二糖编制了DSCONF构象异构体组，并且我们已经评估了使用该组的低成本方法。我们发现MS1-D3 / 6-31 + G（2d，p）对于几何优化和双糖相对能量的计算都是经济高效且准确的。此外，我们注意到，以前已经发现MS1-D3对WATER27集水簇产生良好的相对能量。因此，我们认为该方法适用于研究气相和水溶液中的糖构象。我们注意到，以前已经发现MS1-D3对WATER27集水簇产生良好的相对能量。因此，我们认为该方法适用于研究气相和水溶液中的糖构象。我们注意到，以前已经发现MS1-D3对WATER27集水簇产生良好的相对能量。因此，我们认为该方法适用于研究气相和水溶液中的糖构象。

更新日期：2020-01-14

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