185
Regardless of their pharmaceutical applications, natural bioactive molecules are
also used in the production of agrochemicals, nutraceuticals, cosmetics, etc. They
are mainly found in plant materials as secondary metabolites (Azmir et al. 2013).
On the other hand, proteins are important biomacromolecules because they are
considered as multifunctional biomaterials. Therefore, extraction and purification
of proteins became very interesting for biotechnology industry and for proteins
applications in fields of research and pharmaceuticals (Huang et al. 2015; Xu et al.
2016a, b).
At the same time, direct determination of the analytes in drug and food formulations, or in blood and urine samples, is difficult because of the complexity of the
sample and their presence in very small quantity (Yilmaz and Soylak 2018).
Therefore, developing an extraction method, for the valuable compounds, from their
original matrix into an adequate solvent is the first critical step in the analytical
method because it prepares this sample for a further sensitive and selective quantitative analysis (Rezaee et al. 2006). Hence, it is necessary that the developed extraction method follows the 12 principles of the green chemistry (Anastas and Eghbali
2010). In addition, the extraction method should be time-saving, cheap, and reveal
a high yield.
Several conventional separation techniques are available such as liquid-liquid
extraction, solid-phase extraction, coprecipitation, as well as many exhaustive
extraction methods (maceration, steam or hydro-distillation, pressing, decoction,
infusion, percolation, and Soxhlet extraction) (Chemat et al. 2012; Yilmaz and
Soylak 2018). Despite being expensive, labor-intensive, and time-consuming, these
techniques were always associated with a certain degree of toxicity due to the large
volume of toxic organic solvents used (Alfonsi et al. 2008; Zhuang et al. 2017;
Mohebbi et al. 2018).
Since 1998, ionic liquids have gained much attention to be used as alternative to
organic solvents due to their low vapor pressure and variable viscosities (Khataei
et al. 2018). However, compared to organic solvents, most ionic liquids are more
costly and difficult to prepare. Also they could have a toxic impact on the environment (Gu et al. 2014).
New solvents, so-called deep eutectic solvents, were developed by Abbott since
2003 (Abbott et al. 2003). These solvents are composed of two or more cheap nontoxic components, one of them with the capacity to be a hydrogen bond acceptor,
while the other possesses the properties of a hydrogen bond donor (Florindo et al.
2014; Cvjetko et al. 2016; Moura et al. 2017). Due to the formation of intramolecular hydrogen bonds and Van der Waals interactions, these solvents have much lower
melting point than that of its individual components (Abbott et al. 2004; Moura
et al. 2017).
Natural deep eutectic solvents are prepared from natural metabolites produced
by cell metabolism; therefore, they have been synthesized using simple molecules
present in living cells such as urea, alcohols, organic acids, amines, amino acids,
sugars, choline, and even water (Vanda et al. 2018). Normally, the hydrogen bond
acceptor is an ammonium chloride or an amino acid, while the hydrogen bond donor
is an organic acid or a carbohydrate (Choi et al. 2011; Dai et al. 2014).
6 Methods for Extraction of Bioactive Compounds from Plant and Animal Matter…
Regardless of their pharmaceutical applications, natural bioactive molecules are
also used in the production of agrochemicals, nutraceuticals, cosmetics, etc. They
are mainly found in plant materials as secondary metabolites (Azmir et al. 2013).
On the other hand, proteins are important biomacromolecules because they are
considered as multifunctional biomaterials. Therefore, extraction and purification
of proteins became very interesting for biotechnology industry and for proteins
applications in fields of research and pharmaceuticals (Huang et al. 2015; Xu et al.
2016a, b).
At the same time, direct determination of the analytes in drug and food formulations, or in blood and urine samples, is difficult because of the complexity of the
sample and their presence in very small quantity (Yilmaz and Soylak 2018).
Therefore, developing an extraction method, for the valuable compounds, from their
original matrix into an adequate solvent is the first critical step in the analytical
method because it prepares this sample for a further sensitive and selective quantitative analysis (Rezaee et al. 2006). Hence, it is necessary that the developed extraction method follows the 12 principles of the green chemistry (Anastas and Eghbali
2010). In addition, the extraction method should be time-saving, cheap, and reveal
a high yield.
Several conventional separation techniques are available such as liquid-liquid
extraction, solid-phase extraction, coprecipitation, as well as many exhaustive
extraction methods (maceration, steam or hydro-distillation, pressing, decoction,
infusion, percolation, and Soxhlet extraction) (Chemat et al. 2012; Yilmaz and
Soylak 2018). Despite being expensive, labor-intensive, and time-consuming, these
techniques were always associated with a certain degree of toxicity due to the large
volume of toxic organic solvents used (Alfonsi et al. 2008; Zhuang et al. 2017;
Mohebbi et al. 2018).
Since 1998, ionic liquids have gained much attention to be used as alternative to
organic solvents due to their low vapor pressure and variable viscosities (Khataei
et al. 2018). However, compared to organic solvents, most ionic liquids are more
costly and difficult to prepare. Also they could have a toxic impact on the environment (Gu et al. 2014).
New solvents, so-called deep eutectic solvents, were developed by Abbott since
2003 (Abbott et al. 2003). These solvents are composed of two or more cheap nontoxic components, one of them with the capacity to be a hydrogen bond acceptor,
while the other possesses the properties of a hydrogen bond donor (Florindo et al.
2014; Cvjetko et al. 2016; Moura et al. 2017). Due to the formation of intramolecular hydrogen bonds and Van der Waals interactions, these solvents have much lower
melting point than that of its individual components (Abbott et al. 2004; Moura
et al. 2017).
Natural deep eutectic solvents are prepared from natural metabolites produced
by cell metabolism; therefore, they have been synthesized using simple molecules
present in living cells such as urea, alcohols, organic acids, amines, amino acids,
sugars, choline, and even water (Vanda et al. 2018). Normally, the hydrogen bond
acceptor is an ammonium chloride or an amino acid, while the hydrogen bond donor
is an organic acid or a carbohydrate (Choi et al. 2011; Dai et al. 2014).
6 Methods for Extraction of Bioactive Compounds from Plant and Animal Matter…