In this experimental study, we studied the molecular interactions of l-valine and l-leucine in separate aqueous solutions of D-mannitol at various temperatures and concentrations. The derived parameters, such as apparent molar volume (ϕ_v), limiting apparent molar volume (ϕ_v⁰), viscosity B-coefficient, and Gibbs free energies of activation per mole of solvent and solute, conductance, have been used to predict solute–solvent and solute–solute interactions based on the transition state theory and cosphere overlap model. By adjusting the concentration of l-valine and l-leucine, fluorescence spectra were measured, and the association constant was computed. Hydrophobic–hydrophobic interactions were seen in the ¹H NMR experiments, and these findings were supported by computational research. The primary goal of this research is to comprehend how biologically important D-mannitol interacts with significant amino acids in aqueous solutions, which could be suitable for the pharmaceutical sector. These results are anticipated to offer important foundational knowledge for comprehending how sugar alcohol affects protein conformational stability.

中文翻译：

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通过 DFT 同时优化的物理化学方法探索不同温度下水体系中普遍存在的多种氨基酸-多元醇相互作用

在这项实验研究中，我们研究了不同温度和浓度下D-甘露醇单独水溶液中L-缬氨酸和L-亮氨酸的分子相互作用。导出的参数，例如表观摩尔体积 (phi _v )、极限表观摩尔体积 (phi _v ⁰ )、粘度B系数以及每摩尔溶剂和溶质的吉布斯活化自由能、电导，已用于预测溶质–基于过渡态理论和共球重叠模型的溶剂和溶质-溶质相互作用。通过调节L-缬氨酸和L-亮氨酸的浓度，测量荧光光谱，并计算缔合常数。在¹ H NMR 实验中发现了疏水-疏水相互作用，这些发现得到了计算研究的支持。这项研究的主要目标是了解具有重要生物学意义的D-甘露醇如何与水溶液中的重要氨基酸相互作用，这可能适用于制药行业。预计这些结果将为理解糖醇如何影响蛋白质构象稳定性提供重要的基础知识。