OBTAINING AND INVESTIGATION OF THE BIOLOGICAL ACTIVITY OF GUANIDINE COMPLEXES WITH PECTIN POLYSACCHARIDES

Abstract

Pectin polysaccharides, due to the presence of reactive carboxyl functional groups in the structure, have a high complexing ability. This expands the scope of their practical application for the development of new biologically active substances. In this work, we propose the preparation of complex compounds based on sodium pectate and guanidine hydrochloride. By varying the molar amount of guanidine in relation to the acid groups of the polysaccharide matrix, samples were obtained that differ in the degree of substitution, the content of the amino derivative of the compound, and the inherent viscosity. The optimal ratio of the starting compounds was determined, at which the limiting amount of guanidine is bound to -COO- groups of pectin macromolecules. The structure of the resulting complexes was studied by FTIR spectroscopy. It has been established that the interaction of guanidine with polysaccharide carboxyls is accompanied by a change in the intensity of the absorption bands corresponding to the ionized acid group. Also, the binding of guanidine to the polysaccharide matrix through ionic bonds has been proven by carrying out the hydrolytic cleavage of the complex compound in an acidic medium. It is shown that with an increase in the hydrolysis time from 3 to 24 h, a gradual decrease in the initial degree of substitution of the complex compound is observed. The antimicrobial properties of polymer complexes with different characteristics against Staphylococcus aureus and Escherichia coli were studied.