Liu W, Qin Y, Liu S, Xing R, Yu H, Chen X, Li K, Li P. Synthesis, characterization and antifungal efficacy of C-coordinated O-carboxymethyl chitosan Cu(II) complexes.
Carbohydr Polym 2016;
160:97-105. [PMID:
28115106 DOI:
10.1016/j.carbpol.2016.12.040]
[Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Revised: 12/12/2016] [Accepted: 12/18/2016] [Indexed: 12/01/2022]
Abstract
A novel type of O-carboxymethyl chitosan Schiff bases (O-CSPX) was synthesized via a condensation reaction. After the coordination reaction of cupric ions, Cu(II) complexes (O-CSPX-Cu) were achieved. The theoretical structure of O-CSPX-Cu calculated by Gaussian 09 reveals that the copper ions underwent dsp2 hybridization, coordinated by the carbon atom in the p-π conjugate group and the oxygen atoms in the acetate ion. Then, the structures were confirmed by FT-IR, 1H NMR, CP-MAS 13C NMR, elemental analysis, DSC and XRD. The antifungal properties of O-CSPX-Cu against Phytophthora capsici (P. capsici), Gibberella zeae (G. zeae) and Glomerella cingulata (G. cingulata) were evaluated at concentrations ranging from 0.05mg/mL to 0.20mg/mL. The experiments indicated that the derivatives have significantly enhanced antifungal activity after copper ion complexation compared with the original chitosan. Moreover, it was shown that 0.20mg/mL of O-CSP3-Cu and O-CSP4-Cu can 100% inhibit the growth of P. capsici. The experimental results reveal that the antifungal efficiency is related to the space steric hindrance on the benzene ring, which may provide a novel direction for the development of copper fungicides.
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