Physicochemical Properties, Cytotoxicity, and Antioxidative Activity of Natural Deep Eutectic Solvents Containing Organic Acid

Abstract

Natural deep eutectic solvents (NADES) may be considered ‘designer solvents’ due to their numerous structural variations and the possibility of tailoring their physicochemical properties. Prior to their industrial application, characterization of NADES is essential, including determination of their physicochemical properties, cytotoxicity, and antioxidative activity. The most important physicochemical properties of eight prepared NADES (choline chloride:malic acid, proline:malic acid, choline chloride:proline:malic acid, betaine:malic acid, malic acid:glucose, malic acid:glucose:glycerol, choline chloride:citric acid, and betaine:citric acid) were measured as functions of temperature and water content. In general, the structure of prepared NADES greatly influences their physical properties, which could be successfully modified and adjusted by addition of water. All tested NADES were absolutely benign and noncorrosive for investigated steel X6CrNiTi18-10. Furthermore, cytotoxicity of prepared solvents was assessed toward three human cell lines (HEK-293T, HeLa, and MCF-7 cells), and antioxidative activity was measured by the Oxygen Radical Absorbance Capacity (ORAC) method. With regard to cell viability, all tested NADES containing carboxylic acid could be classified as practically harmless and considered environmentally safe. The ORAC values indicated that the tested NADES displayed antioxidative activity.

Biological activity and sensory evaluation of cocoa by-products NADES extracts used in food fortification

“…The polarity of NADES was determined using Nile red as a solvatochromic probe, as described in Jeong et al (2017). Viscosity was measured according to Mitar et al, (2019).…”

“…On the other side when choline was used as a component of the ready-to-use extract for food fortification, its odour and taste could be unpleasant for consumers (EFSA FEEDAP Panel, 2011;Panić, Radić Stojković, et al, 2019b). Therefore, besides choline-based NADES, we also tested NADES containing betaine as HBA, which have similar characteristics as choline (Mitar, Panić, Kardum, Halambek, & Sander, 2019). For example, comparing the ChCit and BCit, pH value for both of them is < 3, po-larity~50, density~1.2 g cm −3 , EC50 < 2000 mg L −1 and antioxidant capacity~1.5 μmol Trolox equivalent g NADES −1 (Mitar et al, 2019;Panić, Radić Stojković, et al, 2019b).…”

Application of Deep Eutectic Solvents for the Extraction of Rutin and Rosmarinic Acid from Satureja montana L. and Evaluation of the Extracts Antiradical Activity

“…The viscosity of DESs represents one of the biggest drawbacks due to a slow mass transfer, but viscosity can be reduced just by adding H 2 O or increasing the extraction temperature [49]. Apart from reducing viscosity, the addition of water and an increase in temperature can affect pH [50], enabling the extraction of compounds over a wider pH range.…”

In vitro toxicity assessment and enhanced drug solubility profile of green deep eutectic solvent derivatives (DESDs) combined with theoretical validation

“…1 (a that despite resulting in high viscosities, DESs prepared from sugars 15,34a are relatively less toxic to cells than those composed of organic acids. 35,37 It is the cholinium (Ch + ) cations of DESs, which partly dissociate in aqueous solutions, that interact with the charged groups on the surface of the membrane, leading to its disruption. 20,35,36 Further, ternary DESs or DESDs exhibit more toxicity due to the delocalised charges of the hydrogen bonds in comparison with their individual components.…”

“…35,37 It is the cholinium (Ch + ) cations of DESs, which partly dissociate in aqueous solutions, that interact with the charged groups on the surface of the membrane, leading to its disruption. 20,35,36 Further, ternary DESs or DESDs exhibit more toxicity due to the delocalised charges of the hydrogen bonds in comparison with their individual components. Recently, research has revealed the enhanced absorption of DESs in the lipid bilayer of animal cells, while their consequence on the microbial membranes is still indenite.…”