Ionic Liquid-Assisted Fabrication of Bioactive Heterogeneous Magnetic Nanocatalyst with Antioxidant and Antibacterial Activities for the Synthesis of Polyhydroquinoline Derivatives.

Antibacterial materials have obtained much attention in recent years due to the presence of hazardous agents causing oxidative stress and observation of pathogens. However, materials with antioxidant and antibacterial activities can cause toxicity due to their low biocompatibility and safety profile, urging scientists to follow new ways in the synthesis of such materials. Ionic liquids have been employed as a green and environmentally solvent for the fabrication of electrically conductive polymers. In the present study, an antibacterial poly( p -phenylenediamine)@Fe 3 O 4 (P p PDA@Fe 3 O 4 ) nanocomposite was fabricated using [HPy][HSO 4 ] ionic liquid. The chemical preparation of P p PDA@Fe 3 O 4 nanocomposite was initiated through the oxidative polymerization of p -phenylenediamine by ammonium persulfate in the presence of [HPy][HSO 4 ]. The P p PDA@Fe 3 O 4 nanocomposite exhibited antibacterial properties against Gram-negative ( Escherichia coli ) and Gram-positive ( Bacillus subtilis ) bacteria. The P p PDA@Fe 3 O 4 nanocomposite was employed as a heterogeneous nanocatalysis for one-pot synthesis of polyhydroquinoline derivatives using aromatic aldehyde, dimedone, benzyl acetoacetate, and ammonium acetate. Polyhydroquinoline derivatives were synthesized in significant yields (90-97%) without a difficult work-up procedure in short reaction times. Additionally, P p PDA@Fe 3 O 4 nanocatalyst was recycled for at least five consecutive catalytic runs with a minor decrease in the catalytic activity. In this case, 11 derivatives of polyhydroquinoline showed in vitro antioxidant activity between 70-98%.