Polysaccharides, acidic, zone electrophoresis

Nishi et al. [110] used dextran and dextrin as chiral selectors in capillary-zone electrophoresis. Polysaccharides such as dextrins, which are mixtures of linear a-(l,4)-linked D-glucose polymers, and dextrans, which are polymers of D-glucose units linked predominantly by a-(l,6) bonds, have been employed as chiral selectors in the capillary electrophoretic separation of enantiomers. Because these polymers are electrically neutral, the method is applicable to ionic compounds. The enantiomers of basic or cationic drugs such as primaquine were successfully separated under acidic conditions. The effects of molecular mass and polysaccharide concentration on enantioselectivity were investigated. 

Zone electrophoresis is mostly used for biological applications. Peptide separation and the measurement of protein fractions from blood serum (proteinogram of albumin and o-, (3- and 7-globulins) are among the better known applications. This TLC for biochemists is useful for the separation of polysaccharides, nucleic acids (for DNA sequencing), proteins and other colloidal species. 

The protein polysaccharide is hydrolyzed at 100-110° for 3 hours with N sulfuric acid, neutralized with baryta solution, filtered, and the filtrate concentrated to small volume. Zone electrophoresis in borate buffer (pH 8.6) is then carried out for a suitable time, and the paper strip is dried and sprayed with ninhydrin (to locate the amino acids) and with aniline hydrogen phthalate (to detect the reducing sugars). 

Electrophoretic methods are used to separate substances based on their charge-to-mass ratios, using the effect of an electric field on the charges of these substances. These techniques are widely used for charged colloidal particles or macro-molecular ions such as those of proteins, nucleic acids, and polysaccharides. There are several types of electrophoresis, zone electrophoresis being one of the most conunon. 

Carbohydrate analysis using enzymatic hydrolysis and subsequent capillary zone electrophoresis (ENZ/CZE) revealed the number of 4-0-methylglucuronic acid units to be approximately one unit per nineD-xylose residues (Table 4). No glucuronic acid units were detected. The carbohydrate composition of the polysaccharide isolated here from aspen wood is quite similar to that previously reported for typical hardwood xylans . SEC analysis indicated the molecular weight (Mw) to be 15000 g/mol. 

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