Terpene-Based Natural Deep Eutectic Systems as Efficient Solvents To Recover Astaxanthin from Brown Crab Shell Residues

Abstract

The potential of natural deep eutectic systems (NADESs) to efficiently extract astaxanthin (AXT) contained in crab shell wastes was evaluated. Different terpene-based mixtures were prepared and characterized. Aiming at maximizing the AXT recovery, we evaluated the effect of operating temperature and time on the extraction performance. As a proof of concept, this paper also highlights the potential of NADESs for AXT extraction from shrimp shells, mussels, and Haematococcus pluvialis. The biological potential of AXT-rich extracts; the AXT standard; and NADESs, their individual components, and equivalent physical mixtures was evaluated, including cytotoxicity, antiproliferative effects on human colorectal cancer cells, and antimicrobial potential against Staphylococcus aureus and Escherichia coli. Results showed that extractions with menthol:myristic acid (8:1) were able to match the AXT yield obtained by a Soxhlet extraction with acetone. Additionally, when using the same NADESs to recover AXT from the other biomasses under study, there was a 3-to 657-fold increase in yields when compared with the Soxhlet extraction. AXT-rich extracts obtained with NADESs showed antiproliferative and antimicrobial potential. This study suggests that NADESs can truly be used as alternative extraction media for the recovery of AXT from waste biomass and that these systems and respective extracts have the potential to be used as ingredients in industrial applications.

Physicochemical Characterization and Simulation of the Solid–Liquid Equilibrium Phase Diagram of Terpene-Based Eutectic Solvent Systems

“…The temperatures measured lie between 298 to 323 K at an increment of 5 K to study the chemical shifts that take place due to the H-bonded protons for the inter- and intramolecular bonds [ 31 , 32 ]. It has been shown that as the temperature of the sample is increased, a decrease in the intermolecular bonding takes place, which leads to an upfield shift of the H-bonded proton [ 33 ], as shown in Figure 2 . A temperature coefficient ( T coeff ) is obtained to study the magnitude of the shift and the type of H-bonding associated.…”

Deep Eutectic Solvents for the Extraction of Bioactive Compounds from Natural Sources and Agricultural By-Products

“…However, this is highly dependent on the compounds forming NADESs. In the study by Rodrigues et al [10], the NADESs used were mono-and diterpenic-based and showed that all the combinations had some toxicity in Caco-2 cells but could also inhibit the proliferation of HT-29 cells. Additionally, all terpenoid-based NADESs were able to inhibit the growth of S. aureus and E. coli.…”

“…An exhaustive revision of the literature shows that, apart from vegetables, plants, fruits or agricultural by-products, other natural matrices have also served as source of valuable compounds and as occur with previous sources, the use of NADESs as extraction solvents has been also carried out. In this sense, oils obtained from citric, cereals, olives, and palm [40][41][42][43][44][45][46] have been the products most widely evaluated using DESs, although flour [47], eggs [48] and milk [49] as well as nonagricultural by-products [10,50] have been also investigated. As can be seen in Table 3, the studies were focused on the search of different and varied types of molecules including phenolic compounds [40][41][42]46], flavonoids [40,43], terpenoids [10,42,44], proteins [48], lignans [45] or minerals [50].…”

“…[47] In this kind of application, again ChCl was the preferred HBA combined with alcohols, organic acids, sugars or urea [40,41,[43][44][45][46]50] although other quaternary ammonium salts combined with alcohols [42,47,48], lactic acid combined with glucose [49] or terpenes (menthol) together with myristic acid [10] have been also applied. In all cases, natural components were used, thus the application of NADESs has been the choice in the studies developed so far in this area.…”

Selected Monocyclic Monoterpenes and Their Derivatives as Effective Anticancer Therapeutic Agents

“…Rodrigues et al [95] prepared NADESs by (i) mixing various terpenes and also (ii) mixing various terpenes with saturated fatty acid (Table 2) as follows: (S)-(−)-perillyl alcohol 20 (POH), (±)-menthol (ME) and myristic acid (MA) were chosen as molecules that might donate a hydrogen bond through their hydroxyl group, while (S)-(−)-perillyl alcohol (POH), (±)-camphor (CAM), (±)-menthol (ME), eucalyptol (EU) and myristic acid (MA) might act as HBAs through their oxygen atoms. NADESs showed higher cytotoxicity than their corresponding physical mixtures, except for ME:MA eutectic system, prepared at an 8:1 ratio, compared with (±)-menthol and myristic acid physical mixture (PM).…”