Guanidine-Containing Aliphatic Oligomers With Bactericidal Activity

Abstract

A method for the synthesis of reactive aliphatic guanidine oligomers (GO) of different MM by the reaction of oligomeric oxyalkylaliphatic diepoxide with guanidine by varying the ratio of the starting components with subsequent neutralization of the obtained product with hydrochloric acid was developed. A characteristic feature of the structure of the obtained GO oligomers is their amphiphilicity, with the presence of hydroxy-containing guanidine fragments both at the ends and inside the chain. The obtained oligomers are reactive to further chemical transformations. The chemical structure of GO was characterized by FTIR and 1H-NMR spectroscopy, molecular weight was determined by liquid chromatography and titration data. The bactericidal properties of aliphatic guanidine oligomers against a number of gram-positive (Micrococcus luteus, Rhodococcus erythropolis, Rhodococcus rubber, Bacillus megaterium, Bacillus subtilis, Bacillus cereus) and gram-negative bacteria (Escherichia coli, Pseudomonas aeruginosa, Serratia marcescen), depending on the MW of GO were investigated. The minimum inhibitory concentration of aliphatic guanidine oligomers against the studied bacterial strains was determined. It has been shown that the oligomer with the highest content of guanidine fragments has the greatest bactericidal activity and, accordingly, the lowest minimum inhibitory concentration against gram-positive and gram-negative bacteria. The reactive guanidine oligomers obtained by analogy with polyhexamethylene guanidine chloride can be recommended as substances with biocidal and fungicidal properties. In addition, the inherent reactivity of the synthesized GO makes them promising for obtaining various new types of polymers and composites based on them.