Aqueous Biphasic Systems Research Articles

Widening the Stimuli-Responsiveness of Aqueous Biphasic Systems by Changing the Ionic Liquid Cation Basicity.

Herein we demonstrate the formation of new stimuli-responsive aqueous biphasic systems (ABS), able to respond simultaneously to temperature and pH, or just to one stimulus, therefore allowing the design of more sustainable separation processes. This dual behavior is achieved with ABS formed by mono- or dicationic protic ionic liquids as phase-forming components, being defined by the ionic liquid cation chemical structure or its basicity. While ABS comprising monocationic ionic liquids only respond to the effect of temperature, systems comprising dicationic ionic liquids are simultaneously affected by both temperature and pH variations. Dicationic ionic liquids are here identified as the key to unlock a double response to stimuli, which is due to the presence of two pKa values afforded by the cation. The reported findings contribute to increase the customizability of double stimuli-responsive ABS based on ionic liquids, whose development was up to date limited to ionic liquids bearing pH-responsive anions, opening the door towards the development of more sustainable separation processes.

Simultaneous Production of 111In and 109Cd by Alpha Particle Irradiation of natAg Target and Synergistic Aqueous Biphasic Separation using Green Tea Polyphenols

Abstract111In and 109Cd radionuclides were produced by 31 MeV ‐particle irradiation of natAg target. To separate no‐carrier added (NCA) 111In and 109Cd from bulk Ag, Aqueous Biphasic System (ABS) was constructed using twelve salts and two polyethylene glycol (PEG) combinations. Out of all these combinations, only three salts e. g., Na2SO3, Na‐ malonate and Na‐Tartrate and PEG combinations showed significant separation between bulk Ag and NCA radioisotopes. Addition of catechins extracted from green tea to the above ABS systems increased the separation factors many folds. Highest separation factor (SIn/Ag=5.6×104) for 111In was obtained in Na2SO3‐PEG 4000 and 50 mg catechins system. 109Cd retained in NCA state in the Na‐malonate phase after the extraction of 111In and bulk Ag in the catechin‐PEG phase.

Ionic liquid–based aqueous biphasic system as an alternative tool for enhanced bacterial DNA extraction

BackgroundDeveloping an alternative and benign method for DNA extraction is imperative due to the high cost and potential harms associated with conventional techniques. Investigation of Ionic liquid (IL) as a solvent for DNA storage and stability revealed the ability of IL to assist DNA processes. IL–based aqueous biphasic system emerges as a comprehensive extraction platform capitalizing on the task–specificity of ILs and the wide applicability of ABS for biomolecule extractions. Therefore, it is beneficial to optimize an IL–based ABS specifically for DNA extraction, taking into account the fundamental interactions between the IL and DNA. ResultsThe primary objective was to design ABS consisting of Ammonium based ILs, and Potassium phosphate buffer as the salting–out agent for the partitioning of salmon sperm DNA. The analysis focused on optimizing biocompatible anions for the extraction. Moreover, the stability of the DNA in the IL rich phases was analysed to validate the method. The proposed process was then employed for extracting plasmid DNA from bacteria, demonstrating results comparable to those obtained with a commercially available kit. Further validation using agarose gel electrophoresis and transformation of the extracted DNA into E.coli were conducted, producing promising outcomes. Although there is room for improvement in terms of recovery of DNA and reusability of ABS, the described approach is comparable with the conventional one while being cost–effective, and showcases a noticeable and convincing link to eco–friendly processes. SignificanceThere is limited literature on IL–based ABS for DNA extraction, and the existing studies predominantly concentrate on systems derived from Cholinium ILs. However, their high hydrophilicity limits the choice of the second–phase forming component to polymers for the formation of ABS. Ammonium ILs efficiently form biphasic systems with various available salting–out agents, and biocompatible anions are introduced to mitigate the toxicity of the ILs.

Molecular dynamics simulations of betaine-based deep eutectic solvents with varying iso-alcohols chain lengths

Betaine-based (BET) deep eutectic solvents (DESs) made with isoalcohols of varying hydrocarbon chain lengths, namely triethylene glycol (TEG), 1, 2-ethanediol (ETD), 1, 3-propanediol (PPD) and 1, 4-butanediol (BTD) were modelled. Their effects on the formation of aqueous biphasic system (ABS) with 2 M dipotassium phosphate salt solution (K2HPO4) as well as the extraction of common protein molecules, bovine serum albumin (BSA), were studied using molecular dynamics simulation with Gromacs. Qualitative and quantitative data were used to analyse the simulation results, which includes visualised systems in equilibrium, root mean square deviation (RMSD), root mean square fluctuation (RMSF), radius of gyration, radial distribution function (RDF) and hydrogen bond analysis. The results and literature research validated the role of inorganic salt solute concentration on the phase forming ability as well as the possibility of protein denaturation. More investigations and experimental works are to be carried out regarding the type of inorganic salt and its concentration for aqueous biphasic systems (ABSs) with alcohol based DESs and salt solution for protein extraction purposes. This is essential to understand the salting-out effect and to isolate the effects of hydrocarbon chain length from other influencing factors. Additionally, inorganic salt concentrations, presence of ether linkage as well as hydrocarbon chain length is shown to play a role in the dynamics between molecules in the system as well as protein conformational changes. Overall, ABS incorporating PPD and BTD with hydrocarbon chain lengths not exceeding C4 demonstrated superior performance in terms of protein conformational stability and interaction, showcasing their efficacy in protein extraction process.

Designing biodegradable aqueous biphasic systems for the selective separation of enzymes

In this work, the salting-out strength of reline eutectic mixture in aqueous solution of the non-ionic surfactant Triton X-102 has been demonstrated at temperatures between 298.15 and 323.15 K as a preliminary step to be employed in downstream operations of a biotechnological process. The phase diagrams data of reline-based Aqueous Two Phase Systems (ATPS) have been correlated using empirical models based on exponential and polynomial equations. The tie-lines have been empirically ascertained through physical properties characterization and Othmer-Tobias equation was proposed to correlate those data. After having studied the effect of the proposed reline eutectic mixture on two model enzymes (protease and lipase), the performance of this ATPS for selectively separating them was evaluated for three different feed compositions on the same tie-line, demonstrating their pertinence to segregate the lipase to one of the phases (yield about 95 %) and the protease to the other phase (yield about 98 %). These promising results are interesting for application in biotechnological reactions where proteases have been proved to be deleterious for lipases activity, as the biocompatibility of the proposed platform does not involve drastic negative effects on any of the enzymes.

Complete removal of organophosphate pesticides from wastewaters with sustainable ionic liquid-based aqueous two-phase strategy

Due to extensive food production, organophosphate pesticides (OPs) are widely utilized for crop protection, leading to their presence in the environment. The focus of this study was the design of an efficient aqueous biphasic system (ABS) strategy for OP removal, namely, malathion (MAL), azinphos-methyl (AZM), and chlorpyrifos (CHP) from water. Different ionic liquids (ILs) with symmetrical cations were selected as ABS phase-formers (tetrabutylphosphonium salicylate, tetrabutylammonium salicylate, 1,3-dibutylimidazolium dicyanamide, 1,3-dibutylimidazolium salicylate and 1,3-dibutylimidazolium bromide) with citrate salt as a salting-out agent. Initially, phase diagrams were determined, followed by partition studies revealing that the partition of MAL and CHP aligns with the IL- ABS formation trend, while the AZM partition is governed by specific interactions with ILs. For optimization studies, tetrabutylphosphonium-salicylate i.e. [TBP][Sal]-based ABS was chosen, due to obtained high extraction efficiencies of over 99.3 %. After establishing the effects of pH, temperature, tie-line length, and phase ratio on extraction performance, extraction of OPs from a real wastewater sample further confirmed the effectiveness of the designed method achieving complete removal of each pesticide. Furthermore, recovery of IL was achieved using an antisolvent method to precipitate CHP followed by IL-reuse in three consecutive cycles without efficiency decreased. Finally, it was demonstrated that [TBP][Sal] exhibits low cytotoxic potential, indicating that the presence of low amounts of this IL in aqueous media could be acceptable from ecotoxicological standpoint. This study showcased the exceptional potential of the proposed technology for the efficient and sustainable treatment of wastewater contaminated with OPs, affirming its capability to treat significant wastewater volumes.

Guidelines for descriptor assignments for the solvation parameter model by separation techniques

The solvation parameter model uses six compound descriptors to model equilibrium properties in biphasic systems formally defined as excess molar refraction, E, dipolarity/polarizability, S, overall hydrogen-bond acidity, A, overall hydrogen-bond basicity, B, McGowan's characteristic volume, V, and the gas-liquid partition constant on hexadecane at 25 °C, L. The V descriptor can be assigned from structure and the E descriptor for compounds liquid at 20 °C can be calculated from its refractive index and characteristic volume. The E descriptor for compounds solid at 20 °C and the S, A, B, and L descriptors are assigned from experimental properties traditionally obtained by chromatographic, liquid-liquid partition, and solubility measurements. Here I report an efficient experimental design using the Solver method for the accurate assignment of descriptors for neutral compounds that simultaneously minimizes laboratory resources. This multi-technique approach requires 3 retention factor measurements in a 60 °C temperature range per compound on four columns by gas chromatography, 3 retention factor measurements in a 30 % (v/v) acetonitrile composition range per compound on two columns by reversed-phase liquid chromatography, and eight partition constant measurements by liquid-liquid partition in totally organic and aqueous biphasic systems for a total of 26 experimental measurements. The accuracy of the descriptor assignments was validated by comparison with the values in the Wayne State University (WSU) descriptor database taken as the best estimate of the true descriptor values. The E, S, A, B and L descriptors were assigned simultaneously by the Solver method using the above approach without significant bias and with an average absolute deviation (AAD) of 0.054, 0.018, 0.015, 0.013, and 0.040, respectively, compared with the WSU database values, corresponding to a relative absolute average deviation in percent (RAAD) of 7.2, 1.9, 3.6, 5.1, and 0.84 %, respectively, for 32 varied compounds. This streamlined approach represents a significant improvement on earlier single-technique approaches used as the starting point for the development of the multi-technique approach. For compounds of variable hydrogen-bond basicity modifications to the multi-technique approach were implemented while maintaining the same number of experimental measurements. Acceptable descriptor assignments for B/B° were obtained for compounds liquid at 20 °C for which the E descriptor was available by calculation. For solid compounds at 20 °C the E and B/B° descriptors are restricted to qualitative application where approximate values may be acceptable.

Towards Enhanced Tunability of Aqueous Biphasic Systems: Furthering the Grasp of Fluorinated Ionic Liquids in the Purification of Proteins.

This work unfolds functionalized ABSs composed of FILs ([C2C1Im][C4F9SO3] and [N1112(OH)][C4F9SO3]), mere fluoro-containing ILs ([C2C1Im][CF3SO3] and [C4C1Im][CF3SO3]), known globular protein stabilizers (sucrose and [N1112(OH)][C4F9SO3]), low-molecular-weight carbohydrate (glucose), and even high-charge density salt (K3PO4). The ternary phase diagrams were determined, stressing that FILs highly increased the ability for ABS formation. The functionalized ABSs (FILs vs. mere fluoro-containing ILs) were used to extract lysozyme (Lys). The ABSs' biphasic regions were screened in terms of protein biocompatibility, analyzing the impact of ABS phase-forming components in Lys by UV-VIS spectrophotometry, CD spectroscopy, fluorescence spectroscopy, DSC, and enzyme assay. Lys partition behavior was characterized in terms of extraction efficiency (% EE). The structure, stability, and function of Lys were maintained or improved throughout the extraction step, as evaluated by CD spectroscopy, DSC, enzyme assay, and SDS-PAGE. Overall, FIL-based ABSs are more versatile and amenable to being tuned by the adequate choice of the phase-forming components and selecting the enriched phase. Binding studies between Lys and ABS phase-forming components were attained by MST, demonstrating the strong interaction between Lys and FILs aggregates. Two of the FIL-based ABSs (30 %wt [C2C1Im][C4F9SO3] + 2 %wt K3PO4 and 30 %wt [C2C1Im][C4F9SO3] + 25 %wt sucrose) allowed the simultaneous purification of Lys and BSA in a single ABS extraction step with high yield (extraction efficiency up to 100%) for both proteins. The purity of both recovered proteins was validated by SDS-PAGE analysis. Even with a high-charge density salt, the FIL-based ABSs developed in this work seem more amenable to be tuned. Lys and BSA were purified through selective partition to opposite phases in a single FIL-based ABS extraction step. FIL-based ABSs are proposed as an improved extraction step for proteins, based on their biocompatibility, customizable properties, and selectivity.

Membrane-free Zn hybrid redox flow battery using water-in-salt aqueous biphasic electrolytes

In this study, we develop a membrane-free Zn hybrid redox flow battery (RFB) using an unconventional water-in-salt aqueous biphasic system (WIS-ABS). This membrane-free Zn hybrid battery employs soluble ferrocene (Fc) derivative and Zn salt as the active species in the immiscible catholyte and anolyte, respectively. Initially, we demonstrate the potential of using WIS-ABS for a totally aqueous membrane-free Zn battery under static conditions. This static battery operates at a cell voltage of 1.01 V and effectively eradicates the detrimental self-discharge observed in membrane-free batteries, achieving excellent coulombic efficiency (CE) consistently around 100 % over 2000 cycles. However, due to transport limitations in the static configuration, the battery exhibits a low capacity utilization of 17.4 % for the catholyte, ultimately restricting the energy density of the battery. Further improvements in the battery performance are achieved by employing a specially designed RFB cell reactor to operate under real flowing conditions. Impressively, the developed membrane-free Zn hybrid RFB cell significantly shows an improved catholyte utilization, reaching up to 95 %. Furthermore, the membrane-free RFB consistently maintains CE higher than 95 % throughout the cycling process, ultimately achieving a capacity retention as high as 96.5 % after 30 cycles at 100 % depth of discharge. This work highlights the potential of utilizing a water-in-salt aqueous biphasic system to develop a membrane-free Zn hybrid RFB with excellent electrochemical performance, effectively avoiding the undesired self-discharge phenomena.

Enhancing biomarker detection in human serum for lung cancer diagnosis: Aqueous biphasic systems for simultaneous depletion of high-abundance proteins and efficient extraction of CYFRA 21–1

Analysing biomarkers in human serum could be used as an effective and less invasive approach for the diagnosis of lung cancer; however, biomarker detection reliability is highly limited due to matrix effects. Herein, aqueous biphasic systems (ABS) are studied as platforms for human serum pretreatment, allowing the simultaneous depletion of high abundant proteins and biomarker extraction. By using ABS varying the polyethylene glycol (PEG) molecular weight between 400 and 6000 g·mol−1 and adopting phosphate buffer as the other phase-forming component, the depletion of the high abundance serum proteins immunoglobulin G (IgG) and human serum albumin (HSA) is induced at the ABS interphase, through precipitation, forming a three-phase partitioning system (ABS-TPP). Maximum depletion efficiencies of 99 % for IgG and 70 % for HSA were achieved in one step using PEG 1500-based ABS-TPP. On the other hand, lung cancer biomarkers, such as CYFRA 21–1, are extracted to the PEG-rich phase of the same ABS-TPP with recovery yields of 91 %. This work shows that a proper selection of the PEG molecular weight in the ABS composition leads to the efficient depletion of high-abundance proteins and extraction of cancer biomarkers from human serum, in a single step, confirming the potential of ABS for sample pretreatment to improve biomarker analysis.

Sustainable recovery of cobalt and lithium from lithium-ion battery cathode material by combining sulfate leachates and aqueous biphasic systems based on tetrabutylphosphonium-ionic liquids

The consistent expansion of the lithium-ion battery (LIB) market, coupled with their relatively brief lifespan, necessitates the development of efficient and sustainable LIB recycling strategies. Recycling is crucial not only for the recovery of critical metals like Co(II) and Li(I) from the cathode material as a secondary resource but also from an environmental perspective. This study explores the use of a series of aqueous biphasic systems (ABS) with synthesized tetrabutylphosphonium ionic liquids (ILs) and ammonium sulfate as extraction platforms for metals from LIB cathode. Firstly, liquid–liquid equilibrium phase diagrams for each ABS were established, and partitioning experiments were conducted to assess the Co(II), Ni(II), Mn(II), and Li(I) recovery efficiencies. We observed distinct partitioning behaviors for the metals, with tetrabutylphosphonium diethylenetriaminepentaacetate, [TBP][DTPA], showing recovery efficiencies exceeding 98% for Co(II), Ni(II), and Mn(II). At the same time, Li(I) was predominantly retained in the aqueous salt-rich phase. By fine-tuning ABS operational parameters such as pH, temperature, system composition, and phase ratio, we identified optimal conditions for extracting metals from the cathode material of lithium-cobalt-oxide (LCO) batteries using sulfate lixiviate. Introducing [TBP][DTPA] after the leaching process induced ABS, achieving remarkable recovery efficiency over 95% for Co(II) in the IL-rich phase, with all Li(I) remaining in the lower phase. Cobalt was subsequently extracted using oxalic acid to precipitate as Co-oxalate from concentrate, while Li(I) was isolated from the aqueous phase using ammonium carbonate. After the “cleaning” of the IL-rich phase, the [TBP][DTPA] was recovered and reused in four consecutive cycles, with small detected losses on the recovery efficiency of Co(II) and Li(I). Therefore, our innovative strategy combines sulfate-based lixiviants with IL-ABS technology, thereby enhancing selectivity and sustainability within one of the most efficient lixiviant systems widely employed in the industry. This technological advancement presents a promising pathway for the recycling of spent batteries, offering substantial environmental advantages within the well-established and extensively utilized realm of metal recovery technology in the industry.

Aqueous biphasic systems developed with deep eutectic solvents and polymer for the efficient extraction of pigments from beverages

Novel aqueous biphasic systems (ABSs) developed with benzyl-based quaternary ammonium salts-deep eutectic solvents (DESs) and polypropylene glycol (PPG) were herein proposed. The liquid-liquid equilibrium and the partitioning behavior of pigments in the systems were addressed. The results suggested that the shorter the carbon chain length of the DES, the easier to form two phases. The analysis of mixed samples showed that the selective separation was achieved in the ABSs, including 99.47% of tartrazine in the DES-rich phase and 98.47% of sudan III in the PPG-rich phase. Additionally, the systems were successfully applied to the extraction of pigments from the actual beverage samples with recoveries ranging from 93.43% to 102.15%. Furthermore, the study on the separation mechanism indicated that the hydrogen bonding played a significant role in the separation process. All the above results highlight the proposed DES/polymer-based ABSs have great advantages in selective and high-performance separation of pigments from beverages.

Assessment of liquid-liquid partition for the assignment of descriptors for the solvation parameter model

The solvation parameter model uses five system independent descriptors to characterize compound properties defined as excess molar refraction, E, dipolarity/polarizability, S, hydrogen-bond acidity, A, hydrogen-bond basicity, B, and McGowan's characteristic volume, V, to model transfer properties between condensed phases. The V descriptor is assigned from structure. For compounds liquid at 20 °C the E descriptor can be assigned from the characteristic volume and its refractive index. The E descriptor for compounds solid at 20 °C and the S, A, and B descriptors are experimental properties traditionally assigned from chromatographic, liquid-liquid partition, and solubility measurements. In this report liquid-liquid partition constants in totally organic and aqueous biphasic systems are evaluated as a standalone technique for descriptor assignments. Using six totally organic biphasic systems the S, A, and B descriptors were assigned with an average absolute deviation (AAD) of about 0.04, 0.03, and 0.04, respectively, compared with the best estimate of the true descriptor values for 65 compounds. The E descriptor for compounds solid at 20 °C can only be estimated with an AAD of approximately 0.1. For six aqueous biphasic systems the B descriptor is assigned with a lower AAD of 0.028 and higher AAD of 0.08 and 0.05 for the S and A descriptors, respectively, than for the totally organic biphasic systems for compounds with a reliable value for the E descriptor. The preferred system for descriptor assignments utilizes both totally organic biphasic systems (heptane-1,1,1-trifluoroethanol, isopentyl ether-propylene carbonate, isopentyl ether-ethanolamine, heptane-ethylene glycol, heptane-formamide, and 1,2-dichloroethane-ethylene glycol) and aqueous biphasic systems (octanol-water, cyclohexane-water) with the possible substitution of some systems with alternative systems of similar selectivity. For 55 varied compounds this combination of eight organic and aqueous biphasic systems resulted in an AAD of approximately 0.03, 0.02, and 0.02 for the S, A, and B descriptors compared to the best estimate of the true descriptor value. For 30 compounds solid at 20 °C the AAD for the E descriptor of 0.11 is poorly assigned. The relative average absolute deviation in percent (RAAD) corresponds to 9.7 %, 3.1 %. 4.0 % and 8.3 % for E, S, A, and B, respectively, for the eight biphasic systems. Liquid-liquid partition is compared to reversed-phase liquid and gas chromatography as a standalone technique for descriptor assignments.

Green Extraction Strategy Using Bio-Based Aqueous Biphasic Systems for Polyphenol Valorization from Grape By-Product.

Polyphenols are natural compounds with enhanced antioxidant properties. They are present in relatively high concentrations in fruit/vegetable by-products. Therefore, there is a need for the development of efficient and cost-effective methods for the separation and purification of these valuable compounds. Traditional extraction with organic solvents needs to be switched to novel methods that are more efficient, with reduced extraction times and low consumption of organic solvents. Aiming at developing sustainable processes for the separation and purification of phenolic compounds, we used three model compounds, namely resveratrol, quercetin, and gallic acid, to investigate ionic liquid-based aqueous biphasic systems (IL-ABSs) formed by cholinium-based IL in combination with polypropylene glycol with a molecular mass of 400 g/mol (PPG400). The ABS composition in the two-phase region was selected according to a previously determined phase diagram. Extraction studies indicated the preferential partition of resveratrol and quercetin toward the hydrophobic PPG-rich phase that is mainly dominated by its hydrophobic nature and the strong salting-out effect of ILs. On the other hand, due to its considerably hydrophilic nature, gallic acid preferentially migrates toward the IL phase. The achieved results from grape stem extract demonstrated high extraction efficiencies of cholinium dihydrogen phosphate (~99% for resveratrol for the PPG phase and 78% for gallic acid for the IL phase), with considerable selectivity, demonstrating promising outcomes for potential applications.

Sustainable aqueous biphasic system created using sugar-based deep eutectic solvents/ethyl lactate for the green extraction of biomolecules

In recent years, the use of green solvents with efficient extraction techniques has gained considerable interest in the research community. This study proposed a novel aqueous biphasic system (ABS) consisting of a hydrophilic sugar-based deep eutectic solvent (DES) and biodegradable ethyl lactate (EL). To understand the phase behaviour of sugar-based DES-EL ABS, at 298.15 K and at an atmospheric pressure, the phase diagrams were determined, and the effects of the structure of different saccharides such as HBDs on the phase separation were discussed. By fitting the effective excluded volume theory (EEV) model to phase diagram data, the ability of the monosaccharide/disaccharide-based DES to induce phase separation was determined. Furthermore, the tie-line length (TLL) was measured and analysed for the stability of DES in both phases at equilibrium. Finally, extraction experiments of such systems for five target biomolecules (eugenol, vanillin, vanillic acid, gallic acid and rutin) were conducted. The results indicated that the hydrophilic/hydrophobic nature of biomolecules preferentially drives their partitioning behaviour. Eugenol, vanillin, and vanillic acid preferentially migrated to the more hydrophobic EL-rich phase, whereas gallic acid and rutin entered the hydrophilic DES-rich phase. A combination of factors such as pH, viscosity and TLL of the system can also affect the separation efficiency. The results of the extraction experiments confirmed the good feasibility of the proposed system for biomolecular extraction applications.

Do Ionic Liquids Exhibit the Required Characteristics to Dissolve, Extract, Stabilize, and Purify Proteins? Past-Present-Future Assessment.

Proteins are highly labile molecules, thus requiring the presence of appropriate solvents and excipients in their liquid milieu to keep their stability and biological activity. In this field, ionic liquids (ILs) have gained momentum in the past years, with a relevant number of works reporting their successful use to dissolve, stabilize, extract, and purify proteins. Different approaches in protein-IL systems have been reported, namely, proteins dissolved in (i) neat ILs, (ii) ILs as co-solvents, (iii) ILs as adjuvants, (iv) ILs as surfactants, (v) ILs as phase-forming components of aqueous biphasic systems, and (vi) IL-polymer-protein/peptide conjugates. Herein, we critically analyze the works published to date and provide a comprehensive understanding of the IL-protein interactions affecting the stability, conformational alteration, unfolding, misfolding, and refolding of proteins while providing directions for future studies in view of imminent applications. Overall, it has been found that the stability or purification of proteins by ILs is bispecific and depends on the structure of both the IL and the protein. The most promising IL-protein systems are identified, which is valuable when foreseeing market applications of ILs, e.g., in "protein packaging" and "detergent applications". Future directions and other possibilities of IL-protein systems in light-harvesting and biotechnology/biomedical applications are discussed.

Isocyanide-based Multicomponent Reactions (IMCRs) in Water or Aqueous Biphasic Systems.

Isocyanide is an intriguing one-carbon synthon that is frequently employed in a variety of carbon-carbon and carbon-heteroatom bond-forming reactions. Isocyanide-based multicomponent reactions (IMCRs) are effective synthetic tools in organic synthesis for the preparation of complex heterocyclic molecules. The IMCRs in water have become an attractive research direction, enabling simultaneous growth of both IMCRs and green solvents towards ideal organic synthesis. The goal of this review is to provide a general overview of IMCRs in water or biphasic aqueous systems for accessing various organic molecules, as well as an examination of their benefits and mechanistic insights. High atom economies, mild reaction conditions, high yields, and catalyst-free processes are crucial features of these IMCRs in water or biphasic aqueous systems.

Simultaneous Purification of Human Interferon Alpha-2b and Serum Albumin Using Bioprivileged Fluorinated Ionic Liquid-Based Aqueous Biphasic Systems.

Interferon alpha-2b (IFN-α2b) is an essential cytokine widely used in the treatment of chronic hepatitis C and hairy cell leukemia, and serum albumin is the most abundant plasma protein with numerous physiological functions. Effective single-step aqueous biphasic system (ABS) extraction for the simultaneous purification of IFN-α2b and BSA (serum albumin protein) was developed in this work. Effects of the ionic liquid (IL)-based ABS functionalization, fluorinated ILs (FILs; [C​2C​1Im][C​4F​9SO​3] and [N​1112(OH)][C​4F​9SO​3]) vs. mere fluoro-containing IL ([C​4C​1Im][CF​3SO​3]), in combination with sucrose or [N​1112(OH)][H​2PO​4] (well-known globular protein stabilizers), or high-charge-density salt K​3PO​4 were investigated. The effects of phase pH, phase water content (%wt), phase composition (%wt), and phase volume ratio were investigated. The phase pH was found to have a significant effect on IFN-α2b and BSA partition. Experimental results show that simultaneous single-step purification was achieved with a high yield (extraction efficiency up to 100%) for both proteins and a purification factor of IFN-α2b high in the enriched IFN-α2b phase (up to 23.22) and low in the BSA-enriched phase (down to 0.00). SDS-PAGE analysis confirmed the purity of both recovered proteins. The stability and structure of IFN-α2b and BSA were preserved or even improved (FIL-rich phase) during the purification step, as evaluated by CD spectroscopy and DSC. Binding studies of IFN-α2b and BSA with the ABS phase-forming components were assessed by MST, showing the strong interaction between FILs aggregates and both proteins. In view of their biocompatibility, customizable properties, and selectivity, FIL-based ABSs are suggested as an improved purification step that could facilitate the development of biologics.

Bioactive flavonoids partitioning in a deep eutectic solvent/surfactant aqueous biphasic system: Efficiency and thermodynamics

The present study reports the partitioning behavior of three antioxidant flavonoids, including quercetin, chrysin, and daidzein, in an aqueous biphasic system (ABS) formed using a deep eutectic solvent (DES), a non-ionic surfactant (Triton X-100), and water. The efficiency of this ABS in partitioning the flavonoids was investigated by calculating the partition coefficients and recovery efficiencies at different temperatures. The experimental results showed that in all ABSs the flavonoids under study tend to transfer effectively into the surfactant-rich bottom phase in the order of chrysin > quercetin > daidzein. From analyzing the effect of temperature on the partitioning of antioxidants, thermodynamic transfer properties consists of molar Gibbs energy ∆Gm,Flav°, molar enthalpy ∆Hm,Flav° and molar entropy ∆Sm,Flav°were calculated. It is inferred from the results that partitioning of the flavonoids is spontaneous and endothermic. So, increasing the partition coefficient and recovery percentage of the flavonoids by increasing temperature can be explained by the endothermic nature of partitioning process. Finally, molecular interactions between the flavonoid molecules and ABS components were estimated by applying group contribution method. Also, it can be concluded that the extent of interactions between chrysin and components of the ABS (especially the surfactant TX-100) is more than flavonoids quercetin and daidzein.

Conventional methods used in the clinical laboratory for the identification of Ascaris lumbricoides

Soil transmitted helminths affect millions of people around the world, ascariasis can generate different symptoms in the patient, so clinical diagnosis requires an exhaustive study. To date, there is no gold technique for the identification of Ascaris lumbricoides. However, the standard detection method despite its low sensitivity is the thick Kato-Katz extension, which is often used for mapping national programs. This technique can be complemented with methods such as: formalin-ether concentration, Kato- Katz, McMaster, flotation techniques (such as FLOTAC and Mini-FLOTAC), aqueous biphasic system that may be complemented with indirect conventional techniques such as blood count and serological diagnosis (identification of antibodies), the usefulness of these methodologies is limited to evaluating the transmission of this helminth in endemic areas that point to possible elimination. Molecular diagnostics are a futuristic trend, sensitive and specific, but their high costs limit their use in these countries