Tetrabutylphosphonium-salicyl-imine-chitosan metallo-Schiff bases:Supramolecular architectures as multifunctional pharmacological materials.

Abstract

The current work provides a simple synthetic route for the preparation of poly-(phosphonium-salicyl)-grafted chitosan Schiff bases (PPCSB), its M(II) complexes (M = Cu or Pd) and silver nanobiocomposites (NBCs). The ex-situ protocol was used for preparation of nanosilver (AgNPs) using NaBH4 as a reducing agent then capped either by PPCSB or Pd(II)PPCSB to fabricate NBCs {AgNPs@PPCSB, AgNPs@Pd(II)PPCSB}. Structural, morphological and physicochemical characterizations of the new architectures were examined based upon diverse spectral and microscopic techniques. The antibacterial properties of new compoundswas investigated against gram positive (S. aureus, B.subtilis) and gram negative (E. coli, P. aeruginosa) bacterial strains. Unexpectedly, the M(II)PPCSB complexes were found to be more active against all tested bacterial strains than NBCs (AgNPs@PPCSB, AgNPs@Pd(II)PPCSB). Meanwhile, as revealed from ZOI values, the Cu(II)PPCSB is the most potent bactericidal agent against all tested bacterial strains except E. coli species which is more affected by Pd(II)PPCSB