Natural Deep Eutectic Solvents as a New Extraction Media for Phenolic Metabolites in Carthamus tinctorius L.

Abstract

Developing green solvents with low toxicity and cost is an important issue for the biochemical industry. Synthetic ionic liquids and deep eutectic solvents have received considerable attention due to their negligible volatility at room temperature, high solubilization ability, and tunable selectivity. However, the potential toxicity of the synthetic ionic liquids and the solid state at room temperature of most deep eutectic solvents hamper their application as extraction solvents. In this study, a wide range of recently discovered natural ionic liquids and deep eutectic solvents (NADES) composed of natural compounds were investigated for the extraction of phenolic compounds of diverse polarity. Safflower was selected as a case study because its aromatic pigments cover a wide range of polarities. Many advantageous features of NADES (such as their sustainability, biodegradability combined with acceptable pharmaceutical toxicity profiles, and their high solubilization power of both polar and nonpolar compounds) suggest their potential as green solvents for extraction. Experiments with different NADES and multivariate data analysis demonstrated that the extractability of both polar and less polar metabolites was greater with NADES than conventional solvents. The water content in NADES proved to have the biggest effect on the yield of phenolic compounds. Most major phenolic compounds were recovered from NADES with a yield between 75% and 97%. This study reveals the potential of NADES for applications involving the extraction of bioactive compounds from natural sources.

Ultrasound-Assisted Extraction of Polyphenolic Antioxidants from Olive (Olea europaea) Leaves Using a Novel Glycerol/Sodium-Potassium Tartrate Low-Transition Temperature Mixture (LTTM)

“…It should be stressed that optima RL/S determined for polyphenol extraction with conventional solvents may reach up to 100-120 mL g −1 [20,21], but such With respect to C LTTM , it has been suggested that the amount of water required depends on the polarity of the solute (polyphenols), with flavonoid glycosides, such as rutin, being more soluble in LTTMs with a higher water proportion, compared with its aglycone quercetin [12]. On such a ground, it has been supported that the extraction of more polar compounds may require LTTMs with higher water analogy [13]. Additionally, as many LTTMs are rather quite viscous, appropriate viscosity tuning may be achieved through water incorporation, to facilitate extraction efficiency [14].…”

Identification of Flavonoids (Quercetin, Gallic acid and Rutin) from Catharanthus roseus Plant Parts using Deep Eutectic Solvent

“…Nowadays, interests have been increasing in DESs based on choline chloride and their effective uses in extraction and separation of compounds from medicinal plants. Flavonoids [24,25], aromatics [26], chalcones [27], and saponins [28] are the successful compounds being extracted and separated by using DESs from medicinal plants, and DESs extraction provide more efficient extraction than other solvents.…”

Deep Eutectic Solvents: An Overview of its Application as a “Green” Extractant

“…Different types of DESs have been reported by [42] for the extraction of phenolic metabolites from safflower. A significant amount (between 75% and 97%) of phenolic metabolites was recovered from the DES.…”