Eco-friendly synthesis of an antimicrobial polymer (1,4-bis(methacryloyl)piperazine) via maghnite catalysis: in vitro activity and in silico drug-likeness

BackgroundPoly (1,4-bis(methacryloyl)piperazine) (poly (NBMP)) is a piperazine-based polymer with potential biomedical applications. Green clay catalysts, maghnite-H+ and maghnite-Na+; offer an eco-friendly approach for monomer (NBMP) and polymer (poly (NBMP)) synthesis with improved yields and low toxicity.AimTo synthesize poly (NBMP) via green catalysis, evaluate its structural properties, and investigate its antimicrobial potential along with drug-likeness and molecular interaction profiles of its monomer.MethodThe monomer and polymer were synthesized using varying amounts of maghnite-H+ and maghnite-Na+ at controlled temperatures. Structural characterization was performed using FTIR, 1H and 13C NMR, SEM, and DSC. Antibacterial activity was tested against Gram-positive (S. aureus, L. monocytogenes) and Gram-negative bacteria (E. coli, P. aeruginosa, K. pneumoniae). Drug-likeness, toxicity predictions, molecular docking, and molecular dynamics (MD) simulations were conducted to assess binding affinities and complex stability of NBMP with the target bacterial proteins.ResultsMonomer yield increased from 40% to 72% with 0–10 wt% maghnite-H+, while polymer yield rose from 5% to 70% using 0–15 wt% catalyst. Poly (NBMP) exhibited significant antibacterial activity, with inhibition zones of 32 μg/mL against S. aureus and 16 μg/mL against E. coli. Docking studies revealed moderate binding to K. pneumoniae FabG (PDB ID: 6T77, −6.1 kcal/mol). MD simulations confirmed stable complexes with RMSD values of 0.43 nm for E. coli DNA gyrase (PDB ID: 1KZN) and 0.19 nm for K. pneumoniae FabG, along with low RMSF and compact radius of gyration (0.04–0.07 nm).DiscussionThe findings demonstrate that NBMP forms stable interactions with bacterial proteins, supporting its broad-spectrum antimicrobial activity. The eco-friendly synthesis, favorable drug-likeness, and structural stability highlight NBMP as a promising candidate for future biomedical applications. Further in vitro and in vivo studies are recommended to validate its therapeutic potential.