Design and Characterization of Schiff Base Polymer-Ag-Nanocomposites: Advancing Antioxidant With Computational...

For a very long time, Schiff base polymers (SBP) derived from p-phenylenediamine and salicylaldehyde have attracted considerable interest due to their bioactive and coordination properties. Here, we report the synthesis, characterization, computational, and antioxidant activities of Schiff base polymer-Ag-nanocomposites (SBP-AgNC) by combining p-phenylenediamine and salicylaldehyde Schiff bases with silver nanocomposites (AgNC). The reaction of Ag nanoparticles with SBP results in synergistic enhancement of antioxidant activity. The docking results with three different proteins, primarily dihydrofolate reductase of Staphylococcus aureus (3FRB), Sortase C of Streptococcus pneumoniae (3G69), and Glutaredoxin 2 of Escherichia coli (7DKP), shows a binding affinity of -11.6 Kcal/mol toward the dihydrofolate reductase (PDB: 3FRB), -9.0 Kcal/mol with Sortase C (PDB:3G69), and -8.6 Kcal/mol Glutaredoxin 2 (PDB:7DKP). Moreover, hydrogen bonding and π-π stacking interactions play a significant role in the antibacterial activity of SBP; thus, SBP-AgNC1 shows excellent antioxidant activity (IC₅₀ mM [DPPH] = 0.0719 ± 0.04) and good thermal stability up to 350°C. Lastly, this study explored innovative antioxidant materials that are suitable for applications in packaging, food preservation, and biomedicine.