Tuning anti-microbial activity of poly(4-vinyl 2-hydroxyethyl pyridinium) chloride by anion exchange reactions

Abstract

A series of new bioactive polymers with pendant choline analogous group was prepared by anion exchange reaction direct at the quaternary nitrogen of the polycation. Poly(4-vinyl 2-hydroxyethyl pyridinium) chloride was prepared in situ by simultaneous polymerization and quaternization of 4-vinyl pyridine with 2-chloroethanol that also acts as catalyst. The counter anion (Cl-) of the polycation was exchanged by anion exchange reaction with Br-, -OH, -SH, NO3 (-), BF4 (-) or CF3COO-. Evidence of anion exchange was obtained by the characterization of the resultant polymers. The nature of the counter anion has profound effect on their properties including strong anion-dependent anti-microbial activity against bacteria and fungus. Polymer containing -OH was observed to be the most potent anti-microbial agent with the lowest minimum inhibitory concentration against both the classes of microbes studied.