Binding of tetrabutylammonium bromide based deep eutectic solvent to DNA by spectroscopic analysis

DNA nanotechnology in ionic liquids and deep eutectic solvents

Nucleic acids have the ability to generate advanced nanostructures in a controlled manner and can interact with target sequences or molecules with high affinity and selectivity. For this reason, they have applications in a variety of nanotechnology applications, from highly specific sensors to smart nanomachines and even in other applications such as enantioselective catalysis or drug delivery systems. However, a common disadvantage is the use of water as the ubiquitous solvent. The use of nucleic acids in non-aqueous solvents offers the opportunity to create a completely new toolbox with unprecedented degrees of freedom. Ionic liquids (ILs) and deep eutectic solvents (DESs) are the most promising alternative solvents due to their unique electrolyte and solvent roles, as well as their ability to maintain the stability and functionality of nucleic acids. This review aims to be a comprehensive, critical, and accessible evaluation of how much this goal has been achieved and what are the most critical parameters for accomplishing a breakthrough.

The Extraction Using Deep Eutectic Solvents and Evaluation of Tea Saponin

Tea saponins have high surface-active and biological activities and are widely used in chemicals, food, pharmaceuticals, and pesticides. Tea saponins are usually extracted using ethanol or water, but both methods have their disadvantages, including a negative impact on the environment, high energy consumption, and low purity. In this study, we explored an effective process for extracting tea saponins from tea meal using deep eutectic solvents combined with ultrasonic extraction and enzymatic techniques. The experimental results showed that a high extraction efficiency of 20.93 ± 0.48% could be achieved in 20 min using an ultrasonic power of 40% and a binary DES consisting of betaine and ethylene glycol (with a molar ratio of 1:3) at a material-liquid ratio of 1:35 and that the purity of the tea saponins after purification by a large-pore adsorption resin reached 95.94%, which was higher than that of commercially available standard tea saponin samples. In addition, the extracted tea saponins were evaluated for their antioxidant and bacteriostatic activities using chemical and biological methods; the results showed that the tea saponins extracted using these methods possessed antioxidant properties and displayed significant antibacterial activity. Therefore, the present study developed a method for using deep eutectic solvents as an environmentally friendly technological solution for obtaining high-purity tea saponins from tea meal oil. This is expected to replace the current organic solvent and water extraction process and has great potential for industrial development and a number of possible applications.

Local and cooperative structural transitions of double-stranded DNA in choline-based deep eutectic solvents

The possibility of using deep eutectic solvents (DESs) as co-solvents for stabilizing and preserving the native structure of DNA provides an attractive opportunity in the field of DNA biotechnology. The rationale of this work is a systematic investigation of the effect of hydrated choline-based DES on the structural stability of a 30-base-pair double-stranded DNA model via a combination of spectroscopic experiments and MD simulations. UV absorption and CD experiments provide evidence of a significant contribution of DESs to the stabilization of the double-stranded canonical (B-form) DNA structure. Multi-wavelength synchrotron UV Resonance Raman (UVRR) measurements indicate that the hydration shell of adenine-thymine pairs is strongly perturbed in the presence of DESs and that the preferential interaction between H-bond sites of guanine residues and DESs is significantly involved in the stabilization of the dsDNA. Finally, MD calculations show that the minor groove of DNA is significantly selective for the choline part of the investigated DESs compared to the major groove. This finding is likely to have a significant impact not only in terms of thermal stability but also in the modulation of ligand-DNA interactions.

Deep eutectic solvents induced changes in the phase transition behavior of smart polymers: a sustainable future approach

Deep eutectic solvents (DESs) are considered "green" and "sustainable" alternatives to conventional organic solvents and ionic liquids (ILs) due to their characteristic properties and relatively low costs. DESs are considered IL analogs and have attracted consideration as benign media formulations for the synthesis of novel polymers because they satisfy the principle of sustainability. Over the past few years, the use of DESs has resulted in novel pathways for the synthesis of novel materials, biomaterials, functional materials, and ionic soft materials. Furthermore, DESs have been widely applied in the science, industrial, engineering, and technological fields. On the other hand, stimulus-responsive (smart) polymers have been widely utilized in intelligent devices owing to their virtues of good processibility, stimuli and environmental sensitivity, responsivity, and so on. With the introduction of a DES into the smart polymeric matrices, their potential characteristics, biocompatibility, and flexibility endow the corresponding DES-based polymeric materials with intriguing properties, which in turn will broaden their applications in various domains of polymer science and material chemistry. Substantial research has been done in the fabrication of DES-based polymeric materials. Numerous studies have extensively investigated the effects of DESs on biomolecules such as proteins/enzymes and nucleic acids, whereas few have addressed the impact of DESs on the aggregation and phase transition behaviors of smart polymers. This review focuses on mechanistic insights, aggregation behavior, and interactions between smart polymers and DESs. Opportunities and future research perspectives in this blossoming arena are also discussed. It is hoped that this review will pave futuristic pathways for the design and development of advanced DES-based polymeric materials and biomaterials for various applications.

Deep Eutectic Solvents or Eutectic Mixtures? Characterization of Tetrabutylammonium Bromide and Nonanoic Acid Mixtures

Deep eutectic solvents have quickly attracted the attention of researchers because they better meet the requirements of green chemistry and thus have the potential to replace conventional hazardous organic solvents in some areas. To better understand the nature of these mixtures, as well as expand the possibilities of their use in different industries, a detailed examination of their physical properties, such as density, viscosity, the nature of the interactions between their constituents, the phase diagrams, depression of their melting point, and interpretation of these results is necessary. In this work, the mixtures of tetrabutylammonium bromide (TBAB) and nonanoic acid (NA) in different molar ratios are theoretically and experimentally investigated by applying a phase diagram constructed on the basis of differential scanning calorimetry measurements and COSMO-RS model. Spectral properties are investigated based on Fourier transform infrared spectroscopy and density functional theory. The observed eutectic point indicates the formation of a DES in the TBAB−NA system in a 1:2 molar ratio. This is due to the presence of hydrogen bonds between the carboxyl group from the NA molecule and the bromine atom from the TBAB molecule. Other eutectic mixtures are most likely the solutions of TBAB in NA, in which hydrogen bonds predominate between acid molecules.