Synthesis of quaternary piperazine methacrylate homopolymers and their antibiofilm and anti‐quorum sensing effects on pathogenic bacteria.

In this work, poly(glycidyl methacrylate) (PGMA, G) homopolymers with different molecular weights (5600–21,000 gmol−1) were synthesized by atom transfer radical polymerization (ATRP) method. Epoxy groups of PGMA homopolymers were converted to hydroxyl and 1‐methyl piperazin residues by reacting with 1‐methyl piperazine via ring‐opening reaction. The obtained poly(2‐hydroxy‐3‐methyl piperazinepropyl methacrylate) (PHMPPMA, G‐P) homopolymers (from 9450 to 35,900 gmol−1) were reacted with alkyl halides of different carbon chain lengths (methyl‐, ethyl‐, propyl‐, butyl‐, pentyl‐iodides, hexyl bromide) and benzyl chloride (arylhalide) to form quaternary PHMPPMA homopolymers (G‐QP). MIC values varied from 0.125 mg/ml to 5 mg/ml. It was found that homopolymer (1G‐6QP) produced by the modification of PHMPPMA with hexyl iodide with low molecular weight had highest quorum‐sensing inhibition zone ranging from 14.5 ± 0.5 mm (MIC) and 10.0 ± 0.5 mm (MIC/4) as well as best violacein inhibition 61.0 ± 2.2% (MIC) to 17.3 ± 0.6% (MIC/8). Homopolymer (1G‐BzQP) produced by the modification of PHMPPMA with benzyl chloride with the lowest molecular weight had best biofilm inhibition ranging from 77.83 ± 1.60% (MIC) to 18.23 ± 0.87% (MIC/8) on S. aureus, 75.70 ± 5.20% (MIC) to 14.25 ± 1.10% (MIC/8) on E. coli and from 86.16 ± 0.83% (MIC) to 12.41 ± 0.76% (MIC/8) on C. albicans. The synthesized homopolymers can be used to combat microbial resistance and severity of infections. [ABSTRACT FROM AUTHOR]