## 5 Using DES to Extract Bioactive Compounds from Other Natural Sources
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline
**Sample** & **Discive Compound** & **Disactive Compound** & **Odider Ratio Amount** & **Extraction Procedure** & **Analytical Technique** & **Extraction Efficiency** & **Comments** & **Ref.** \\  & **Water Content** & & & & & & & \\ \hline  & & & & & & & & \\  & & & & & & & & \\ \multirow{4}{*}{Tea seed oil} & 31 phenolic compounds & & & UHFLC-QQQ- & & & & & \\  & identified, 25 phenolic compounds & & ChClglycerol (2:6 g) & LLE & MS/MS & 8.4-2.710\({}^{-50}\) & - & & \\  & compounds quantified & & UHFLC-Q-Te-MS/MS & & & & & \\  & & & UHFLC-Q-Te-MS/MS & & & & \\  & & & & & & & \\  & & & & & & & \\  & & & & & & & \\  & & & & & & & \\  & & & & & & & \\  & & & & & & & \\  & & & & & & & \\  & & & & & & & \\  & & & & & & & \\  & & & & & & & \\ \hline  & & & & & & & & \\  & & & & & & & & \\  & & & & & & & & \\ \hline  & & & & & & & & \\ \multirow{4}{*}{ Wheat Boar} & Folic acid & TOMACisomary & & & & & & \\  & alcohol & alcohol & & & & & & \\  & (vitamin [99]) & & SLE, VA-DLIME & HPLC-UV & 92-100 [FOOTNOTE:]Footnote [ENDFOOTNOTE] & & & & \\  & & & & & & & & \\  & & & & & & & & \\  & & & & & & & \\  & & & & & & & & \\  & & & & & & & \\ \hline \hline \end{tabular}
\end{table} 
Table 3: _Cont._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. However, the selection of the final applied solvent was based, in most cases, on the results obtained from previous studies in which several HBDs or even HBAs and variated molar ratio combinations were explored to reach the best extraction performance. In this sense, it should be highlighted the work carried out by [PERSON] et al. [41], in which liquid-liquid extraction (LLE) using NADESs was applied for profiling free and bound phenolic compounds in tea seed oil. The authors tested different binary and ternary DESs using ChCl as HBA and xylitol, malonic acid, glycerol, ethylene glycol and propylene glycol as HBDs and formed using variated molar ratio. Results showed that all DESs had potential for the extraction of free and bound phenolic acid and flavonoids except for some bound flavonoids at low levels of concentration. In general terms, malonic HBDs showed the lower extraction capacity respect to reference MeOH/water extraction solvents. The authors explained this behavior based on the capacity of organic acids to donate hydrogen bonds which can come up with a competition between malonic acid and phenolic compounds to interact with DESs molecules and the low pH of the organic acid that could favor the degradation of phenolic compounds. Sugar-based DESs showed good extraction capacity for phenolic acids, however, its high viscosity makes it unsuitable for the extraction performance unless water is added, which makes the procedure more complex. Finally, regarding alcohol based NADESs, those increase their extraction efficiency with polarity, being glycerol the most polar and the one with the highest extraction yields, surely due to the similarity with phenolic compounds. Therefore, ChCl:glycerol was applied as the most suitable extraction solvent. The procedure allowed the identification of 31 phenolic compounds and the quantification of 25 of them by application of UHPLC-(QqQ)-MS/MS and UHPLC-(QTOF)-MS/MS, respectively. As previously indicated, apart from ChCl, other quaternary salts were also investigated for the extraction of terpenoids, vitamins or proteins. An interesting example is the strategy developed by [PERSON] et al.