On the Interactions between Amino Acids and Ionic Liquids in Aqueous Media

Abstract

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.

Physico‐chemical and Spectroscopic Approach to Analyse the Behaviour of Surface‐Active Ionic Liquid and Conventional Surfactant in Aqueous Glycine

“…However, in the case of IL, the IL-amino acid interactions mainly occur at the level of the apolar moieties of the IL and the hydrophobic side chains of the biomolecules. But due to its highly hydrophilic character, glycine has no affinity for the interactions with apolar parts of SAIL cation and anion, inducing most significant saltingout influence as a result of preferential hydration of glycine molecules [25,26]. Thus, the presence of glycine in SAILwater system results in a decrease in the CMC of TBADS.…”

“…The study of interactions of bio-molecules with surfactants has drawn attention for the control of various industrial and biotechnological processes [23][24][25][26]. It is, therefore, fruitful to investigate the solution behavior of model compounds such as amino acids, peptides, and their derivatives to understand the interactions/micellization behavior of surfactants in the presence of bioactive molecules.…”

Mesoporous and biocompatible surface active silica aerogel synthesis using choline formate ionic liquid

“…These low viscous amino acid ionic liquids may be designed for potential applications such as electrolytes, lubricants, soft materials, etc. [16,17]. Quaternary ammonium compounds with sweeteners such as saccharinate and acesulfamate based ionic liquids have dual functions like antimicrobial activity, and sweetening property [18].…”

Interacciones de la DL-Alanina en Soluciones Acuosas de Trifluorometanosulfonato de 1-Butil, 3-Metilimidazolio a Diferentes Temperaturas

“…De acuerdo con (Natarajan et al, 1990;Tome et al, 2009) los ΔV ϕ o para los aminoácidos pueden ser considerados como el resultado de la suma del volumen de Van der Waals VVW, el volumen asociado con los huecos o espacios vacios VV y el volumen de contracción debido a la electrostricción VS. Asumiendo que VVW y VV tienen la misma magnitud en agua que en soluciones acuosas para la misma clase de solutos ( Palani et al, 2011), los valores de ΔV ϕ o se pueden explicar de acuerdo al cambio en el volumen de contracción debido al efecto de electrostricción, por tanto la presencia [BMIm] [OTF] aumenta el efecto de electrostricción causada por el aminoácido, a causa de los grupos metil y butil del [BMIm][OTF], lo cual resulta en un incremento de la contracción. Este efecto se debe reflejar en los valores de número de hidratación calculados utilizando el tratamiento de (Millero et al, 1978), según el cual el volumen molar aparente a dilución infinita se puede representar mediante la ecuación (6):…”