Preparation and Characterization of Novel Cationic Chitosan Derivatives Bearing Quaternary Ammonium and Phosphonium Salts and Assessment of Their Antifungal Properties

• Published in: Molecules (Basel, Switzerland) Vol. 22; no. 9; p. 1438
• Main Authors: Tan, Wenqiang, Li, Qing, Dong, Fang, Chen, Qiuhong, Guo, Zhanyong
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 31.08.2017; MDPI
• Subjects: Acetylation; Ammonium; Antifungal activity; Antifungal Agents - chemical synthesis; Antifungal Agents - pharmacology; Antimicrobial agents; Biomaterials; Biomedical materials; cationic chitosan derivatives; Cations; Chitosan; Chitosan - analogs & derivatives; Chitosan - chemical synthesis; Chitosan - pharmacology; Data processing; Drug Stability; electron-withdrawing ability; Fourier transforms; Fungicides; Fusarium; Fusarium - drug effects; Fusarium oxysporum; Hydrogen-Ion Concentration; Infrared spectroscopy; Magnetic Resonance Spectroscopy; Methylation; Microbial Sensitivity Tests; Molecular weight; NMR; Nuclear magnetic resonance; Organophosphorus Compounds - chemical synthesis; Organophosphorus Compounds - pharmacology; Quaternary Ammonium Compounds - chemical synthesis; Quaternary Ammonium Compounds - pharmacology; quaternary ammonium salts; quaternary phosphonium salts; Raw materials; Salts; Solubility; Spectroscopy, Fourier Transform Infrared; Spectrum analysis; Surgical implants; Thermogravimetric analysis; Vibration; electron-withdrawing ability; quaternary ammonium salts; antifungal activity; cationic chitosan derivatives; quaternary phosphonium salts
• ISSN: 1420-3049; 1420-3049
• DOI: 10.3390/molecules22091438

Chitosan is an abundant and renewable polysaccharide, its derivatives exhibit attractive bioactivities and the wide applications in various biomedical fields. In this paper, two novel cationic chitosan derivatives modified with quaternary phosphonium salts were successfully synthesized via trimethylation, chloride acetylation, and quaternization with tricyclohexylphosphine and triphenylphosphine. The structures and properties of synthesized products in the reactions were characterized by FTIR spectroscopy, ¹H-NMR, P-NMR, elemental and thermogravimetric analysis. The antifungal activities of chitosan derivatives against four kinds of phytopathogens, including , , , and were tested using the radial growth assay in vitro. The results revealed that the synthesized cationic chitosan derivatives showed significantly improved antifungal efficiency compared to chitosan. It was reasonably suggested that quaternary phosphonium groups enabled the obviously stronger antifungal activity of the synthesized chitosans. Especially, the triphenylphosphonium-functionalized chitosan derivative inhibited the growth of most effectively, with inhibitory indices of about 80% at 0.5 mg/mL. Moreover, the data demonstrated that the substituted groups with stronger electron-withdrawing ability relatively possessed greater antifungal activity. The results suggest the possibility that cationic chitosan derivatives bearing quaternary phosphonium salts could be effectively employed as novel antifungal biomaterials for application in the field of agriculture.