CICECO, Departamento de Química, Universidade de Aveiro, 3810-193 Aveiro, Portugal.
J Phys Chem B. 2009 Oct 22;113(42):13971-9. doi: 10.1021/jp906481m.
The understanding of the molecular-level interactions between biomolecules and ionic liquids (ILs) in aqueous media is crucial for the optimization of a number of relevant biotechnological processes. In this work, the influence of a series of amino acids on the liquid-liquid equilibria between 1-butyl-3-methylimidazolium tricyanomethane and water was studied to evaluate the preferential interactions between these three compounds. The solubility effects observed are dependent on the polarity, size, and charge distribution of the amino acid side chains and are explained in terms of a refined version of the model proposed earlier (Freire et al. J. Phys. Chem. B 2009, 113, 202; Tome et al. J. Phys. Chem. B 2009, 113, 2815) for ion specific effects on aqueous solutions of imidazolium-based ILs. Although acting through different mechanisms, salting-in and salting-out phenomena possess a common basis which is the competition between water-amino acid side chain, IL-amino acid side chain, and water-IL interactions. The delicate balance between these interactions is dependent on the relative affinities of the biomolecules to water molecules or to IL cation and anion and determines the trend and magnitude of the solubility effect observed.
理解生物分子与离子液体（ILs）在水介质中的分子水平相互作用对于优化许多相关生物技术过程至关重要。在这项工作中，研究了一系列氨基酸对 1-丁基-3-甲基咪唑三氰胺与水之间液-液相平衡的影响，以评估这三种化合物之间的优先相互作用。观察到的溶解度效应取决于氨基酸侧链的极性、大小和电荷分布，并根据早先提出的模型（Freire 等人，J. Phys. Chem. B 2009，113，202；Tome 等人，J. Phys. Chem. B 2009，113，2815）进行了改进，用于解释离子对基于咪唑的 ILs 水溶液的特殊效应。尽管盐析和盐溶现象通过不同的机制起作用，但它们具有共同的基础，即水分子与氨基酸侧链、IL 与氨基酸侧链以及水分子与 IL 之间的竞争。这些相互作用之间的微妙平衡取决于生物分子对水分子或 IL 阳离子和阴离子的相对亲和力，并决定了观察到的溶解度效应的趋势和幅度。
