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Proteins are inherently unstable, which limits their use as therapeutic agents. However, the use of biocompatible cosolvents or surfactants can help to circumvent this problem through the stabilization of intramolecular and solvent-mediated interactions. Ionic liquids (ILs) have been known to act as cosolvents or surface-active compounds. In the presence of proteins, ILs can have a beneficial effect on their refolding, shelf life, stability, and enzymatic activities. In the work described herein, we used small-angle X-ray scattering (SAXS) to monitor the aggregation of different concentrations of ILs with protein models, lysozyme (Lys) and bovine serum albumin (BSA), and fluorescence microscopy to assess micelle formation of fluorinated ILs (FILs) with Lys. Furthermore, coarse-grained molecular dynamics (CG-MD) simulations provided a better understanding of Lys–FIL interactions. The results showed that the proteins maintain their globular structures in the presence of FILs, with signs of partial unfolding for Lys and compaction for BSA with increased flexibility at higher FIL concentrations. Lys was encapsulated by FIL, thus reinforcing the potential of ILs to be used in the formulation of protein-based pharmaceuticals. [ABSTRACT FROM AUTHOR]

[Display omitted] • F127 polymeric micelles explored as nanocarriers for new chloroquine-derived bile salts. • These surface-active ionic liquids (SAILs) are per se highly effective antiplasmodial drugs. • In-depth physicochemical characterization of F127/SAIL mixed micelles carried out. • SAILs favor mixed micelle formation opening possibilities for biological assays. • Antiplasmodial efficacy strongly enhanced for SAILs in F127 micelles compared to free SAILS. Colloidal nanocarriers can play a key role in the efficacious delivery of drugs, including antimalarials. Here, we investigated the ability of polymeric micelles of the block copolymer F127 to act as nanovehicles for two organic salts derived from chloroquine and human bile acids, namely, chloroquinium cholate (iCQP1) and chloroquinium glycocholate (iCQP1g). We have previously reported the strong in vitro antiplasmodial activity of these salts, which displayed IC 50 values of 13 and 15 nM against blood forms of Plasmodium falciparum , respectively. By deriving from amphiphilic lipids, iCQP1 and iCQP1g also enclose the ability to act as surface-active ionic liquids (SAILs). The micellization properties of neat F127 and of the F127/SAIL mixtures were initially investigated to gain physicochemical insight into the interaction between polymer and bioactive SAILs, resorting to differential scanning calorimetry, surface tension measurements and dynamic light scattering. Micelle formation by F127 is an endothermic process strongly temperature and concentration dependent. Interestingly, this process is significantly changed when the molar fraction of SAIL (x SAIL) in the F127/SAIL mixture is varied between 0.33 and 0.90. Both SAILs favor the formation of mixed micelles by decreasing the micellization temperature, and (observed only when for x SAIL = 0.33) by synergistically decreasing the cmc. Concomitantly, the micellar size is reduced from 18 to 13 nm as x SAIL is increased from 0.33 to 0.90. Crucially, in vitro assays show that when the SAILs are loaded into F127 polymeric micelles, their antiplasmodial efficacy is substantially enhanced, with a significant drop in IC 50 , especially for the iCQP1/F127 system. This opens new possibilities for the nanoformulations of antimalarial compounds. [ABSTRACT FROM AUTHOR]

The effectiveness of surface-active ionic liquids (SAILs) as lubricant additives in both polar and apolar base liquids has been investigated on stainless steel surfaces at both macroscale and nanoscale. The SAILs studied are composed of trihexyltetradecylphosphonium ([P 6,6,6,14 ]+) cations paired with either dioctyl sulfosuccinate ([AOT]-) or dodecyl sulphate ([DS]-) anions. The polar and apolar base liquids used to dilute the SAILs are diethyl succinate ((CH 2 CO 2 Et) 2) and hexadecane (HD), respectively. The friction coefficients of pure [P 6,6,6,14 ] [AOT] and [P 6,6,6,14 ] [DS] are up to ∼80 % lower than those of (CH 2 CO 2 Et) 2 and HD. Remarkably, diluted solutions containing as little as 5 wt% SAIL in either (CH 2 CO 2 Et) 2 or HD exhibit lubricity comparable to that of pure SAILs, revealing their excellent potential as lubricant additives. The high lubricity of the SAIL solutions in both (CH 2 CO 2 Et) 2 and HD is attributed to the adsorption of anions onto the positively charged stainless steel surface, resulting in the formation of a robust boundary layer that reduces surface contact and facilitates smooth sliding. These insights aid the development of advanced, cost-effective lubricant additives, with potential applications across various industrial sectors. [Display omitted] [ABSTRACT FROM AUTHOR]

• New surfactants based on ionic liquids equipped with carbohydrate moieties were synthesized. • They were used to elucidate the mechanism of purification of single-walled carbon nanotubes. • The experiments revealed insight about the underlying interactions at the heart of the separation. Single-walled carbon nanotubes (SWCNTs) have substantial application potential in many branches of technology. Considering that the spatial order of carbon atoms in SWCNTs determines their properties, the characteristics of a material can be adjusted for a specific application by using only selected types of SWCNTs. Unfortunately, SWCNT purification is challenging as the mechanisms of the currently available sorting techniques are not fully understood. The aqueous two-phase extraction (ATPE) method is a promising approach in this context as it offers SWCNT separation in an aqueous environment, so elucidation of its workings is essential. To come closer to achieving this goal, we synthesized a new range of surfactants based on ionic liquids equipped with amphiphilic carbohydrate moieties. We then examined how the modification of their structure influences SWCNT partitioning in two-phase systems composed of poly(ethylene glycol) and dextran. We concluded that the capacity of the ATPE method for purification of SWCNTs depended upon establishing a sufficient degree of order or disorder in the aqueous medium caused by the introduction of chemical compounds of a kosmotropic and chaotropic nature, respectively. [ABSTRACT FROM AUTHOR]

We report on a comparative study of three novel non-halogenated surface-active ionic liquids (SAILs), which contain a surface-active anion, 2-ethylhexyl sulfate ([EHS]−), and phosphonium or imidazolium cations: tetrabutylphosphonium ([P4,4,4,4]+), trihexyl(tetradecyl)phosphonium ([P6,6,6,14]+), and 1-methyl-3-hexylimidazolium ([C6C1Im]+). Thermal and electrochemical properties i.e., ionic conductivities at different temperatures and electrochemical potential windows of these SAILs were thoroughly studied. SAIL's electrochemical performance as electrolytes was also examined in a multi-walled carbon nanotubes (MWCNT)-based supercapacitor over a wide range of temperatures from 253 to 373 K. We observed that the electrode material in the supercapacitor cell with [C6C1Im][EHS] as an electrolyte has a higher specific capacitance (Celec in F g−1), a higher electric energy density (E in W h kg−1), and a higher electric power density (P in kW kg−1) as compared to the other studied SAILs, [P4,4,4,4][EHS], [P6,6,6,14][EHS] and [N8,8,8,8][EHS] (from our preceding study) in a temperature range from 253 to 373 K: At the scan rate of 2 mV s−1 a supercapacitor cell with a MWCNT-based electrode and [C6C1Im][EHS], [P4,4,4,4][EHS] and [P6,6,6,14][EHS] as electrolytes has the specific capacitance, Celec = 148, 90 and 47 F g−1 and the energy density, E = 82, 50 and 26 W h kg−1, respectively, when measured at 298 K. For the named three SAILs at the scan rate of 2 mV s−1, a two- to three-fold increase in the specific capacitance and the energy density values was measured at 373 K: Celec = 290, 198 and 114 F g−1 and E = 161, 110 and 63 Wh kg−1, respectively. The solution resistance (Rs), charge transfer resistance (Rct) and equivalent series resistance (ESR) all decreased two- to three-fold with an increase in temperature from 298 to 373 K. With the high specific capacitance and enhanced energy and power density and wider electrochemical potential window as compared to the molecular organic and aqueous electrolytes, these SAILs can be used for high-temperature electrochemical applications, such as high power and energy storage devices. In particular, up to now, [C6C1Im][EHS] and [P4,4,4,4][EHS] are the most appropriate candidates for such applications.

Phenylketonuria (PKU) is an autosomal recessive disease caused by deficient activity of human phenylalanine hydroxylase (hPAH), which can lead to neurologic impairments in untreated patients. Although some therapies are already available for PKU, these are not without drawbacks. Enzyme-replacement therapy through the delivery of functional hPAH could be a promising strategy. In this work, biophysical methods were used to evaluate the potential of [N1112(OH)][C4F9SO3], a biocompatible fluorinated ionic liquid (FIL), as a delivery system of hPAH. The results herein presented show that [N1112(OH)][C4F9SO3] spontaneously forms micelles in a solution that can encapsulate hPAH. This FIL has no significant effect on the secondary structure of hPAH and is able to increase its enzymatic activity, despite the negative impact on protein thermostability. The influence of [N1112(OH)][C4F9SO3] on the complex oligomerization equilibrium of hPAH was also assessed. [ABSTRACT FROM AUTHOR]

Proteins are inherently unstable, which limits their use as therapeutic agents. However, the use of biocompatible cosolvents or surfactants can help to circumvent this problem through the stabilization of intramolecular and solvent-mediated interactions. Ionic liquids (ILs) have been known to act as cosolvents or surface-active compounds. In the presence of proteins, ILs can have a beneficial effect on their refolding, shelf life, stability, and enzymatic activities. In the work described herein, we used small-angle X-ray scattering (SAXS) to monitor the aggregation of different concentrations of ILs with protein models, lysozyme (Lys) and bovine serum albumin (BSA), and fluorescence microscopy to assess micelle formation of fluorinated ILs (FILs) with Lys. Furthermore, coarse-grained molecular dynamics (CG-MD) simulations provided a better understanding of Lys–FIL interactions. The results showed that the proteins maintain their globular structures in the presence of FILs, with signs of partial unfolding for Lys and compaction for BSA with increased flexibility at higher FIL concentrations. Lys was encapsulated by FIL, thus reinforcing the potential of ILs to be used in the formulation of protein-based pharmaceuticals.

[Display omitted] • Three green Surface-active ionic liquids were synthesized. • Density and speed of sound behavior of gabapentin in aqueous ionic liquids solutions is reported. • The drug-solvent interactions were evaluated using thermodynamic analysis. • Some thermophysical properties were calculated. Understanding the hydration behavior of pharmaceutical compounds is crucial for optimizing their solubility and bioavailability. Investigation on the hydration properties of gabapentin, a potent anticonvulsant drug, in the presence of: Surface-active ionic liquids (SAIL) derived from mono, di, and tri ethanolamine octanoate at temperature ranges of 288.15–318.15 K have been carried out. Moreover, it has been observed distinct temperature-dependent effects on the hydration behavior, elucidating the thermodynamic aspects governing the interactions between gabapentin and the surfactants. Furthermore, the investigation demonstrates the role of surfactant concentration and structure in modulating the hydration behavior of gabapentin. Protic SAILs have emerged as valuable compounds with unique properties, showing significant importance in both industrial and pharmaceutical applications. These compounds possess both ionic and surfactant characteristics, making them versatile and offering diverse functionality. The thermodynamic approach has been supported by density and speed of sound measurements. The standard partial molar properties have been determined by molality dependency of apparent molar volumes, V φ , and apparent molar isentropic compressibility, κ φ using Redlich-Meyer equation. Also, apparent molar isobaric expansibility E φ 0 , and Hepler's constant has been applied to determine the structure making or breaking tendency of the solvation of gabapentin. Based on the thermodynamic properties, it has been concluded hydration of the gabapentin in the presence of the studied SAIL led to increase solute-solvent interactions between the gabapentin and SAIL in aqueous solutions and structure making tendency in the solution bulk. [ABSTRACT FROM AUTHOR]

Phenylketonuria (PKU) is an autosomal recessive disease caused by deficient activity of human phenylalanine hydroxylase (hPAH), which can lead to neurologic impairments in untreated patients. Although some therapies are already available for PKU, these are not without drawbacks. Enzyme-replacement therapy through the delivery of functional hPAH could be a promising strategy. In this work, biophysical methods were used to evaluate the potential of [N1112(OH)][C4F9SO3], a biocompatible fluorinated ionic liquid (FIL), as a delivery system of hPAH. The results herein presented show that [N1112(OH)][C4F9SO3] spontaneously forms micelles in a solution that can encapsulate hPAH. This FIL has no significant effect on the secondary structure of hPAH and is able to increase its enzymatic activity, despite the negative impact on protein thermostability. The influence of [N1112(OH)][C4F9SO3] on the complex oligomerization equilibrium of hPAH was also assessed.

Alkyl ether carboxylates are part of a new class of ionic liquids based on the Concept of Melting Point Lowering due to Ethoxylation (COMPLET) and possess unique aggregation behaviour due to the simultaneous anionic and non-ionic nature of the surfactant anion. Previous publications on H[C8E8c] (Polyoxyethylene(8) octyl ether carboxylic acid) and its monovalent salts have shown a variety of phases in aqueous systems with a transition from small spherical micelles at high water contents towards a phase of interdigitated head groups at low water contents. In the present paper, we examine the shorter homologue H[C8E5c] (Polyoxyethylene(5) octyl ether carboxylic acid) and its di- and trivalent transition and rare earth metal salts using X-ray scattering methods in the small- and wide-angle range (SWAXS). These measurements confirm the presence of spherical micelles in diluted aqueous systems which aggregate and whose head groups interdigitate at higher concentrations of the isotropic, non-birefringent ionic liquid. Swelling experiments yield two-dimensional swelling of the microstructure, and combined with the scattering pattern, the data infer prolate spheroidal direct (o/w) micelles with interdigitated head groups, which align to form short linear chains. These chains are offset to form a localised hexagonal close-like packing of the micelles. Most interesting, within this packing, the metal cations are confined into channels between the micelles in linear chains with ion-ion distances of 0.4–1.1 nm. In particular, in the water-free ionic liquid, this confinement may be responsible for some of the unique properties of these systems. It is suggested that the confinement of the cations leads to strong ion-ion aggregation that could be at the origin of the very peculiar magnetic properties of these simple one-component liquids, which contrasts with classical ferrofluids, in which magnetic nanoparticles are dispersed in another liquid. • Alkyl ether carboxylate ionic liquids derived from H[C8E5c] form direct (o/w) micelles at any concentration. • At high concentrations, the head-groups of the prolate micelles are interdigitated without the presence of any 'bulk' water. • A hexagonal arrangement of these aligned interdigitated prolate micelles which swells in two dimensions is proposed. • Metal cations are not randomly distributed, but strongly confined between the micelles in linear chains as well as planes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Ten monocationic and dicationic SAILs − imidazolium chlorides and bis-imidazolium dichlorides synthesized and characterized. • The surface and antimicrobial properties depended on the alkyl chain or linker length. • Analyzed SAILs are an attractive choice for biomedical applications or as surfactants. In the present study, a series of monocationic and dicationic surface-active ionic liquids (SAILs) were synthesized and characterized. The structures of SAILs were confirmed by spectral analyses of 1H NMR and 13C NMR. Additionally, the thermal properties of the synthesized monocationic and dicationic SAILs were determined using thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). Nevertheless, the crucial part of this work is to confirm the strong relationship between the structure, surface activity, and biological action of newly SAILs on bacteria (both G(-) and G(+)) and fungi. The elongation of the alkyl chain or linker in the imidazolium cation results in a decrease in the minimum inhibitory concentration (MIC). Dicationic SAILs containing more than eight carbon atoms in the linker showed antimicrobial activity. In contrast, a cutoff effect was observed for their monocationic analog. [ABSTRACT FROM AUTHOR]

• Development of a biocompatible platform for immunoglobulin Y (IgY) purification from egg yolk. • Thermoresponsive systems in presence and absence of surface-active ionic liquids were studied. • Thermoresponsive systems in absence of ionic liquids enhance the IgY purity to 54%. • Ionic-liquid-based systems boost the IgY purity in a single step up to 69%. • An integrated and cost-effective downstream process is proposed to recover IgY with 73% purity. Immunoglobulin Y (IgY) represents an important class of antibodies, being present in egg yolk, with relevant medical applications and involving non-invasive methods of extraction. However, due to the complexity of egg yolk, the purification levels required for use in most medical applications demands the application of multi-step and cost-intensive techniques. Therefore, it is of upmost importance to develop a biocompatible and cost-effective downstream process to purify IgY from egg yolk. In this work, IgY was purified from the egg yolk water-soluble protein fraction (WSPF) by the application of thermoresponsive aqueous micellar two-phase systems (AMTPS) composed of the non-ionic surfactant Triton X-114 and surface-active ionic liquids (SAILs) as co-surfactants. The best thermoresponsive systems allowed, in a single step, to recover IgY in the surfactant-poor phase with a purity level of 69%, and up to 73% if consecutive extraction cycles are performed, while maintaining the structural integrity of the antibodies. Considering these results, a downstream process was designed and proposed, consisting of four main steps: (i) recovery of the WSPF; (ii) purification of IgY by applying AMTPS; (iii) isolation of the IgY from the main solvents using an ultrafiltration step; (iv) recycling of the AMTPS phase-forming components by precipitating the contaminant proteins. [ABSTRACT FROM AUTHOR]

• Solid-phase extraction was the technique used to purify pigments. • The pigments investigated were obtained from a microalga. • A commercial resin was applied of the separation of chlorophylls from other pigments. • Ionic liquids were successfully used to elute chlorophylls from the resin. • The continuous process in a column was also performed with success. There is a need for handy and fast techniques to purify biomolecules, increasing their stability and value, because the separation units are current bottlenecks in downstream processes. Solid-phase extraction is a technique that enables the purification of a compound by its adsorption from a liquid matrix. The AmberLite™ HPR900 OH resin allows the separation of chlorophylls from complex extracts, however the recovery of the chlorophylls is not easy to achieve. An innovative procedure to elute the chlorophyll from AmberLite™ HPR900 OH, based on the use of aqueous solutions of surface-active ionic liquids is proposed in this work. The operational conditions were optimized, showing that the resin can be reused for at least five cycles without losing its efficiency and the chemical structures of the pigments recovered were identified. [ABSTRACT FROM AUTHOR]

• Synthesis and characterization of 8 ionic liquids with surfactant properties. • Thermal properties, micelle diameter and critical micellar concentration were determined. • Toxicity towards Aliivibrio fischeri was determined. • Most ionic liquids display more atractive properties than the conventional surfactant. With the goal of finding sustainable solvents, novel ionic liquids (ILs) with low ecotoxicity features have been a target of research. Among these, ILs with surface-active characteristics play a significant role in the food, cosmetic, pharmaceutical, household cleaning and other detergent industries. Most surface-active ILs reported up to date are imidazolium-based, which may raise some environmental and health-related concerns. Aiming the development of ILs with surfactant properties and low ecotoxicity, in this work, novel surface-active analogues of glycine-betaine ILs (AGB-SAILs) combined with the dodecylbenzenesulfonate ([DBS]-) anion have been synthesized and characterized. The synthesized AGB-SAILs were characterized chemically by elemental analysis and spectroscopic methods. Their thermal properties, critical micellar concentration, micelle diameter and ecotoxicity against Aliivibrio fischeri were determined, being these properties compared with the commercial surfactant sodium dodecylbenzenesulfonate (SDBS). It is shown that all investigated AGB-SAILs are liquid at room temperature and thermally stable. Furthermore, most of them display a lower critical micellar concentration and lower toxicity towards Aliivibrio fischeri than SDBS, thus being good alternatives to the commercial surfactant in a wide range of applications. [ABSTRACT FROM AUTHOR]

Since injection administration for diabetes is invasive, it is important to develop an effective transdermal method for insulin. However, transdermal delivery remains challenging owing to the strong barrier function of the stratum corneum (SC) of the skin. Here, we developed ionic liquid (IL)-in-oil microemulsion formulations (MEFs) for transdermal insulin delivery using choline-fatty acids ([Chl][FAs])-comprising three different FAs (C18:0, C18:1, and C18:2)-as biocompatible surface-active ILs (SAILs). The MEFs were successfully developed using [Chl][FAs] as surfactants, sorbitan monolaurate (Span-20) as a cosurfactant, choline propionate IL as an internal polar phase, and isopropyl myristate as a continuous oil phase. Ternary phase behavior, dynamic light scattering, and transmission electron microscopy studies revealed that MEFs were thermodynamically stable with nanoparticle size. The MEFs significantly enhanced the transdermal permeation of insulin via the intercellular route by compromising the tight lamellar structure of SC lipids through a fluidity-enhancing mechanism. In vivo transdermal administration of low insulin doses (50 IU/kg) to diabetic mice showed that MEFs reduced blood glucose levels (BGLs) significantly compared with a commercial surfactant-based formulation by increasing the bioavailability of insulin in the systemic circulation and sustained the insulin level for a much longer period (half-life > 24 h) than subcutaneous injection (half-life 1.32 h). When [Chl][C18:2] SAIL-based MEF was transdermally administered, it reduced the BGL by 56% of its initial value. The MEFs were biocompatible and nontoxic (cell viability > 90%). They remained stable at room temperature for 3 months and their biological activity was retained for 4 months at 4 °C. We believe SAIL-based MEFs will alter current approaches to insulin therapy and may be a potential transdermal nanocarrier for protein and peptide delivery.

The relevance of ionic liquids (ILs) is now well established in many fields, as their unique properties make them appealing as 1) greener alternatives to organic solvents (first-generation ILs), 2) tunable task-specific materials (second-generation ILs), and 3) multifunctional players in life and pharmaceutical sciences (third-generation ILs). This third wave of ILs encompasses a wide range of compounds, from bioactive molecules with single or even dual therapeutic action, to potential ingredient molecules for drug formulation and transport systems. In this context, the focus of this review is the emergent role of surface-active ionic liquids (SAILs) in drug development and delivery., (© 2021 Wiley-VCH GmbH.)

The surface activity and aggregation behavior of catanionic mixtures of imidazolium- or pyridinium-based surface-active ionic liquids (SAILs) and sodium N -lauroyl sarcosinate (Na-LS) in aqueous solution were investigated. The effects of the alkyl chain length, the polar head group and functional groups in the SAIL molecule on the interfacial properties and self-assembly of the catanionic mixtures were evaluated by surface tension and dynamic light scattering measurements. In addition, the toxicity of the catanionic surfactant mixtures against bacteria and fungi was studied. The SAIL-LS mixed systems reduced water surface tension with high effectiveness and efficiency, and had a lower critical aggregation concentration compared to the individual components. In all the catanionic systems investigated, synergistic effects caused by strong electrostatic and hydrophobic interactions resulted in negative interaction parameter values, which increased with the alkyl chain length and in the order of non-functionalized < amide-functionalized < ester-functionalized SAILs. The structure of the mixed aggregates in the SAIL-LS catanionic systems depended on the hydrophobicity of the SAIL, the micelle-vesicle transition being driven by the alkyl chain length. The catanionic systems exhibited similar microbial toxicity to that of individual SAIL components and behaved like broad-spectrum antimicrobials. Unlabelled Image • Surface activity, aggregation and microbial toxicity of SAIL-LS catanionic mixtures studied • SAIL-LS mixtures show higher surface activity and lower cac than individual components. • Structure of SAIL-LS aggregates, micelles or vesicles, depends on the SAIL hydrophobicity. • C 12 -C 14 ester- or amide-functionalized SAIL-LS form spontaneously small vesicles (~100 nm) • SAIL-LS mixtures show a broad spectrum of antimicrobial activity. [ABSTRACT FROM AUTHOR]

In this work the influence of benzoate, ortho -, meta - and para -hydroxybenzoate anions, as counterions, on micellization process of 1-dodecyl-3-methyl-imidazolium cation in water is investigated by isothermal titration calorimetry (ITC) in the temeprature range between 278.15 and 318.15 K. ITC experimental data were analyzed by the help of an improved mass-action model, yielding the values of critical micelle concentration, cmc, the degree of counterion binding, β , aggregation number, n , standard heat capacity, Δ M c p θ, enthalpy, ∆ M H θ, entropy, ∆ M S θ, and Gibbs free energy, ∆ M G θ of micellization. It was found that the investigated systems behave mainly like common ionic surfactants and already investigated SAILs: the micellization process of investigated systems is entropically driven at low temperatures, whereas at high temperatures the enthalpic contribution becomes equally important. The last is especially important in the case of ortho-hydroxybenzoate, which incorporates into micellar structure affecting also the entropy-enthalpy compensation. But evidently, the presence and position of –OH group in the counterion influence considerably the micellization process. Δ M c p θ values were further discussed in the light of the removal of water molecules from contact with nonpolar surface area upon micelle formation. All the values are negative, the most in the case of benzoate anion, which could be ascribed to the absence of –OH group. To refine the thermodynamic parameters obtained from ITC, the molecular simulations were performed. First, it is shown that the binding energies between anion and cations increase in the order from benzoate to para -, meta - and ortho -hydroxybenzoate, which coincide with ∆ M H θ values. Second, it is demonstrated that water around counterions is strongly perturbed leading to differences in Δ M c p θ. Unlabelled Image • Micellization of 1-dodecyl-3-methyl-imidazolium cation in water was investigated. • As counterions, benzoate, ortho -, meta - and para -hydroxybenzoate anions, were taken. • The standard thermodynamic parameters of micellization process are derived. • To refine the thermodynamic parameters, the molecular simulations were performed. • Calculated binding energies at anion and cations coincide with found energetics. [ABSTRACT FROM AUTHOR]

Twelve surface-active ionic liquids (SAILs) and surface-active derivatives, based on imidazolium, ammonium, and phosphonium cations and containing one, or more, long alkyl chains in the cation and/or the anion, were synthetized and characterized. The aggregation behavior of these SAILs in water, as well as their adsorption at solution/air interface, were studied by assessing surface tension and conductivity. The CMC values obtained (0.03-6.0 mM) show a high propensity of these compounds to self-aggregate in aqueous media. Their thermal properties were also characterized, namely the melting point and decomposition temperature by using DSC and TGA, respectively. Furthermore, the toxicity of these SAILs was evaluated using the marine bacteria Aliivibrio fischeri (Gram-negative). According to the EC 50 values obtained (0.3-2.7 mg L -1 ), the surface-active compounds tested should be considered "toxic" or "highly toxic". Their ability to induce cell disruption of Escherichia coli cells (also Gram-negative), releasing the intracellular green fluorescent protein (GFP) produced, was investigated. The results clearly evidence the capability of these SAILs to act as cell disruption agents., (© 2019 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.)

Triterpenic acids (TTAs) are well known for their relevant biological properties and have been facing an increasing interest for nutraceutical and pharmaceutical applications. To overcome the concerns associated to the commonly used volatile organic solvents for their extraction from biomass, here we investigate the potential of aqueous solutions of ionic liquids (ILs) as alternative solvents. The solubility of ursolic acid (UA) was firstly determined in several aqueous solutions of ILs (hydrotropes or surface-active) at 30°C to appraise the dissolution phenomenon. Conventional surfactants were also investigated for comparison purposes. The collected data reveal a remarkable enhancement in the solubility of UA (8 orders of magnitude) in surface-active ILs aqueous solutions when compared to pure water. Afterwards, the potential of these ILs aqueous solutions was confirmed by their use in the extraction of TTAs from apple peels. Total extractions yield of TTAs of 2.62 wt.% were obtained using aqueous solutions of surface-active ILs at moderate conditions, overwhelming the extraction yields of 2.48 wt.% obtained with chloroform and 1.37 wt.% with acetone using similar conditions.