title: Synthesis, characterization and antifungal efficacy of C-coordinated O-carboxymethyl chitosan Cu(II) complexes.
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 dsp2hybridization, 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-MAS13C 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.
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Weixiang
authors.initials: W
authors.lastname: Liu
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China. Electronic address: ykqin@qdio.ac.cn.
authors.forename: Yukun
authors.initials: Y
authors.lastname: Qin
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Song
authors.initials: S
authors.lastname: Liu
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Ronge
authors.initials: R
authors.lastname: Xing
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Huahua
authors.initials: H
authors.lastname: Yu
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Xiaolin
authors.initials: X
authors.lastname: Chen
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China.
authors.forename: Kecheng
authors.initials: K
authors.lastname: Li
authors.affiliation: Key Laboratory of Experimental Marine Biology, Institute of Oceanology, Chinese Academy of Sciences, Qingdao 266071, China. Electronic address: pcli@qdio.ac.cn.
authors.forename: Pengcheng
authors.initials: P
authors.lastname: Li
mesh_terms: D048271:Chitosan / Q000031:analogs & derivatives* / Q000737:chemistry; D003300:Copper / Q000737:chemistry*; D005659:Fungicides, Industrial / Q000737:chemistry*; D005874:Gibberella / Q000187:drug effects; D020081:Phyllachorales / Q000187:drug effects; D010838:Phytophthora / Q000187:drug effects; D012545:Schiff Bases; D017550:Spectroscopy, Fourier Transform Infrared
chemical_list: D005659:Fungicides, Industrial; C504164:O-carboxymethylchitosan; D012545:Schiff Bases; D003300:Copper; D048271:Chitosan
keywords: 3-Amino-2-methylbenzoic acid (PubChem CID: 2733699); 3-Amino-4-chlorobenzoic acid (PubChem CID: 76092); 3-Amino-4-methylbenzoic acid (PubChem CID: 75568); 4-Amino-2-chlorobenzoic acid (PubChem CID: 66646); 4-Amino-2-methylbenzoic acid (PubChem CID: 241632); 4-Amino-3-methylbenzoic acid (PubChem CID: 75598); Acetic acid (PubChem CID: 176); Acetylacetone (PubChem CID: 31261); Antifungal; Chitosan; Chitosan (PubChem CID: 71853); Coordination; Copper complex; Cupric acetate (PubChem CID: 8895); Diethyl ether (PubChem CID: 3283); Ethanol (PubChem CID: 702); Methanol (PubChem CID:887); Monochloroacetic acid (PubChem CID: 300); Sodium hydroxide (PubChem CID: 14798)