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.

Synthesis and Characterization of Inulin Derivatives Bearing Urea Groups with Promising Antifungal Activity

“…Chlorine atoms show strong electronegativity and have a key role in inhibiting the growth of fungi by disrupting cell walls and cytoplasmic membranes, resulting in fungal death . These results were in agreement with those of Tan et al who also reported that the antifungal potential of compounds was associated with the electronegativity of the substituted groups, with the antifungal activity of samples increasing with increasing electronegativity. In samples with the same number of chlorine atoms, the different positions of those atoms could have different effects on their antifungal activity, given the order 4CBUCAIL > 3CBUCAIL > 2CBUCAIL.…”

Synthesis, Characterization, and Antifungal Property of Hydroxypropyltrimethyl Ammonium Chitosan Halogenated Acetates

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Novel Amino-Pyridine Functionalized Chitosan Quaternary Ammonium Derivatives: Design, Synthesis, and Antioxidant Activity

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