Antibacterial Activity of Carboxymethyl Chitosan Dialdehyde Starch Schiff Base and its Metal Complex

Abstract

Carboxymethyl chitosan dialdehyde starch Schiff base (CMCDAS) and its metal complexes were synthesized by corn starch (St), sodium periodate, carboxymethyl chitosan and metal ions (copper, zinc, nickel, silver), and were characterized by Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), thermogravimetric analyzer (TGA), energy dispersive spectroscopy (EDS) and X-ray powder diffraction (XRD). The antibacterial activities of CMCDAS against E. coli and S. aureus increased according with its increasing nitrogen content, and the best minimum inhibitory concentrations (MIC) to E. coli and S. aureus were 30 mg/mL, respectively. Furthermore, the minimum inhibitory concentrations (MIC) of the metal Complexes (copper, nickel, silver, and zinc) against S. aureus were 7.50 mg/mL, 30 mg/mL, 30 mg/mL, and 1.88 mg/mL, respectively; and against E. coli were 7.50 mg/mL, 15 mg/mL, 15 mg/mL, and 0.94 mg/mL, respectively.

Crowding Effect-Induced Zinc-Enriched/Water-Lean Polymer Interfacial Layer Toward Practical Zn-Iodine Batteries

“…Due to its characteristic ethylene diamine tetraacetic acid (EDTA)-type amino-carboxylate chelating structure, the CCS molecule inherently manifests heightened chelation capabilities toward an array of metal ions (such as Cu 2+ , Ni 2+ , Co 2+ , Sn 4+ , Al 3+ , Pb 2+ , Ca 2+ , La 3+ , Nd 3+ ) in contrast to the chitosan molecules. This augmentation in chelation propensity is observed to correlate positively with the progressive augmentation of carboxymethyl substitution. − In light of this, we judiciously selected multivalent metals (Al, Sn, and Cu) which were heightened contemporary investigation to serve as the electrodeposition substrates. Consequently, an ultrathin M-CCS (M is metal ion) polymer layer was successfully fashioned atop the metal surface (Figure S5 in the Supporting Information).…”