COMPARATIVE STUDIES OF THE CHEMICAL INTERACTION OF GUANIDINE WITH DIALDEHYDE CELLU-LOSE AND PECTIN

The presence of reactive aldehyde groups in the elementary units of dialdehyde polysaccharides enables to enter easily into a condensation reaction with reagents containing primary amino groups in the structure. This naturally expands the possibilities of obtaining new derivatives of polysaccharides with physiologically active properties. In this study, we synthesized azomethine derivatives of cellulose and pectin differing in the degree of substitution and the content of the nucleophilic reagent in the composition of the reaction products through chemical interaction of guanidine with macromolecules of dialdehyde polysaccharides. Therefore, regularities of the reaction of nucleophilic substitution of aldehyde groups of oxidized polysaccharides with guanidine were revealed. It was found that the interaction of guanidine amino groups with oxidized pectin in contrast to dialdehyde cellulose occurs through the formation of azomethine and ionic bonds. Moreover, the possibility of obtaining guanidine-containing derivatives of cellulose and pectin with different structural characteristics by varying the molar ratio of the nucleophile and the oxidation state of the starting polysaccharides was proved. The composition and structure of the reaction products were studied by physicochemical methods of analysis. The stability and rate of cleavage of guanidine groups from the macromolecules of dialdehyde cellulose and dialdehyde pectin were studied by hydrolysis of the synthesized samples in acidic and alkaline media.