title: Synthesis, characterization, and antifungal property of chitosan ammonium salts with halogens.
abstract: In this study, a group of novel water soluble chitosan ammonium salts with halogens were successfully synthesized, including chitosan-bromoacetate (CSB), chitosan-chloroacetate (CSC), chitosan-dichloroacetate (CSDC), chitosan-trichloroacetate (CSTC), and chitosan-trifluoroacetate (CSTF), and their antifungal activities against three kinds of phytopathogens were comparatively estimated by hypha measurement in vitro, respectively. The fungicidal assessment revealed that the synthesized chitosan derivatives had higher antifungal activity than chitosan. Especially, the inhibitory indices of CSTC and CSTF against three kinds of phytopathogens were higher than 70% at 1.0mg/mL. Generally, the antifungal activity decreased in the order: CSTF>CSTC>CSDC>CSC>CSB>chitosan. Apparently, the order of antifungal activity was consistent with the electronegativity of different substituted groups with halogens. The substituted groups with stronger electronegativity could augment the positive charge densities of cationic amino groups by drawing more electrons from the cationic amino groups of chitosan ammonium salts, which demonstrated that the protonation of amino groups was significant for the antifungal activity of chitosan derivatives.
authors.affiliation: Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Wenqiang
authors.initials: W
authors.lastname: Tan
authors.affiliation: Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.
authors.forename: Qing
authors.initials: Q
authors.lastname: Li
authors.affiliation: Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Dong
authors.affiliation: Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China; University of Chinese Academy of Sciences, Beijing 100049, China.
authors.forename: Lijie
authors.initials: L
authors.lastname: Wei
authors.affiliation: Key Laboratory of Coastal Biology and Bioresource Utilization, Yantai Institute of Coastal Zone Research, Chinese Academy of Sciences, Yantai 264003, China. Electronic address: zhanyongguo@hotmail.com.
authors.forename: Zhanyong
authors.initials: Z
authors.lastname: Guo
mesh_terms: D064751:Ammonium Compounds / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D000935:Antifungal Agents / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D066241:Carbon-13 Magnetic Resonance Spectroscopy; D048271:Chitosan / Q000138:chemical synthesis* / Q000737:chemistry / Q000494:pharmacology*; D005670:Fusarium / Q000187:drug effects; D006219:Halogens / Q000737:chemistry / Q000494:pharmacology*; D008826:Microbial Sensitivity Tests; D066244:Proton Magnetic Resonance Spectroscopy; D012492:Salts / Q000737:chemistry / Q000494:pharmacology*; D012995:Solubility; D017550:Spectroscopy, Fourier Transform Infrared; D014867:Water / Q000737:chemistry
chemical_list: D064751:Ammonium Compounds; D000935:Antifungal Agents; D006219:Halogens; D012492:Salts; D014867:Water; D048271:Chitosan
keywords: Antifungal activity; Chitosan ammonium salts; Group electronegativity