104
interestingly, are simply executed (Lu et al. 2012). The chemical modification of
polysaccharides through sulfonylation has been broadly studied due to the properties obtained of the modified products. Sulfonylation protocols have been developed for various polysaccharides including curdlan, dextran, and botryosphaeran
(Jindal et al. 2013; Brandi et al. 2011), mannogalactan (Gracher et al. 2010), carboxymethyl cellulose (Shao et al. 2014).
Various biomacromolecules have been investigated in an attempt to obtain antithrombotic agents that may function as alternatives to heparin. In this respect, sulfonated polysaccharides are therefore of great interest (Gracher et al. 2010). Brandi
et al. (2011) sulfonated and resulfonated botryosphaeran (1→3; 1→6)-β-D-glucan)
and demonstrated that the polysaccharide have a potential of thrombin inhibition
similar to that of heparin. Accordingly, the sulfonated botryosphaeran showed anticoagulant activity in vitro. Lin et al. (2004) investigated a sulfonated (1→3)-β-Dglucan in vitro and in vivo and exhibited potentiated antitumor activity on Sarcoma
180 cells derived by Poria cocos and their results verified antiproliferative activity
significantly higher than the unmodified glucan. Cui et al. (2008) showed high antioxidant potential of a sulfonated (1→6)-β-D-glucan obtained by Pueraria lobata
(Willd.) Ohwi. Additionally, sulfonated polysaccharides have been found for
improving their solubility in water. They have been used as texturizing agents in
foods, as food supplements, and in the development of new drugs (Jindal et al. 2013).
Chemical Modification by Carboxymethylation
In recent years, carboxymethylation of several natural polymers including cellulose, starch, dextran, chitin and chitosan have been investigated. Carboxymethylation
takes place by substituting hydroxyl groups on the polysaccharide with carboxyl
groups. Derivatives obtained by carboxymethylation exhibit properties with excellent applications in the chemical, pharmaceutical, food and cosmetic industries (Ye
et al. 2012). Carboxymethylation is typically performed under alkaline conditions
through suspension of the biopolymer in chloroacetic acid (Carvalho et al. 2013).
Carboxymethylated β-glucan from corn kernels obtained a molecule with improved
solubility, decreased viscosity, and enhanced antioxidant activity (Chen et al. 2013a,
b). Moreover, similar to sulfonated polysaccharides, carboxymethylation will trigger enhancements in the physicochemical and biological properties of these
polysaccharides.
Derivatization through carboxymethylation on a (1→3)-β-D-glucan from Poria
cocos has been demonstrated and it has been verified that it significantly increased
solubility and a dose-dependent elimination of free radicals (Wang et al. 2009).
Carboxymethylation of (1→3)-β-D-glucan from baker’s Saccharomyces cerevisiae
yeast has been observed and administered with cyclophosphamide (an alkylating
antineoplastic agent), showed increased inhibition of Lewis carcinoma cells, and
inhibited pulmonary metastases, thereby improving the efficacy of cyclophosphamide action (Kogan et al. 2002). Similarly, carboxymethylated (1→3)-β-D-glucan
N. Jan et al.
interestingly, are simply executed (Lu et al. 2012). The chemical modification of
polysaccharides through sulfonylation has been broadly studied due to the properties obtained of the modified products. Sulfonylation protocols have been developed for various polysaccharides including curdlan, dextran, and botryosphaeran
(Jindal et al. 2013; Brandi et al. 2011), mannogalactan (Gracher et al. 2010), carboxymethyl cellulose (Shao et al. 2014).
Various biomacromolecules have been investigated in an attempt to obtain antithrombotic agents that may function as alternatives to heparin. In this respect, sulfonated polysaccharides are therefore of great interest (Gracher et al. 2010). Brandi
et al. (2011) sulfonated and resulfonated botryosphaeran (1→3; 1→6)-β-D-glucan)
and demonstrated that the polysaccharide have a potential of thrombin inhibition
similar to that of heparin. Accordingly, the sulfonated botryosphaeran showed anticoagulant activity in vitro. Lin et al. (2004) investigated a sulfonated (1→3)-β-Dglucan in vitro and in vivo and exhibited potentiated antitumor activity on Sarcoma
180 cells derived by Poria cocos and their results verified antiproliferative activity
significantly higher than the unmodified glucan. Cui et al. (2008) showed high antioxidant potential of a sulfonated (1→6)-β-D-glucan obtained by Pueraria lobata
(Willd.) Ohwi. Additionally, sulfonated polysaccharides have been found for
improving their solubility in water. They have been used as texturizing agents in
foods, as food supplements, and in the development of new drugs (Jindal et al. 2013).
Chemical Modification by Carboxymethylation
In recent years, carboxymethylation of several natural polymers including cellulose, starch, dextran, chitin and chitosan have been investigated. Carboxymethylation
takes place by substituting hydroxyl groups on the polysaccharide with carboxyl
groups. Derivatives obtained by carboxymethylation exhibit properties with excellent applications in the chemical, pharmaceutical, food and cosmetic industries (Ye
et al. 2012). Carboxymethylation is typically performed under alkaline conditions
through suspension of the biopolymer in chloroacetic acid (Carvalho et al. 2013).
Carboxymethylated β-glucan from corn kernels obtained a molecule with improved
solubility, decreased viscosity, and enhanced antioxidant activity (Chen et al. 2013a,
b). Moreover, similar to sulfonated polysaccharides, carboxymethylation will trigger enhancements in the physicochemical and biological properties of these
polysaccharides.
Derivatization through carboxymethylation on a (1→3)-β-D-glucan from Poria
cocos has been demonstrated and it has been verified that it significantly increased
solubility and a dose-dependent elimination of free radicals (Wang et al. 2009).
Carboxymethylation of (1→3)-β-D-glucan from baker’s Saccharomyces cerevisiae
yeast has been observed and administered with cyclophosphamide (an alkylating
antineoplastic agent), showed increased inhibition of Lewis carcinoma cells, and
inhibited pulmonary metastases, thereby improving the efficacy of cyclophosphamide action (Kogan et al. 2002). Similarly, carboxymethylated (1→3)-β-D-glucan
N. Jan et al.