Novel 1,2,3-triazolium-functionalized starch derivatives: Synthesis, characterization, and evaluation of antifungal property.

Four novel 1,2,3-triazolium-functionalized starch derivatives were synthesized by N -alkylating the precursor starch derivatives with 1,2,3-triazole with iodomethane based on cuprous-catalyzed azide-alkyne cycloaddition (CuAAC). The detailed structural characterization was investigated by means of FTIR, UV-vis, 1 H NMR, and 13 C NMR spectra. The antifungal activities of starch derivatives against Colletotrichum lagenarium , Fusarium oxysporum , and Watermelon fusarium , were then assayed by hypha measurement in vitro . The fungicidal assessment revealed that compared with starch and starch derivatives with 1,2,3-triazole, 1,2,3-triazolium-functionalized starch derivatives displayed tremendously enhanced antifungal activity. Especially, the inhibitory indices of 6-(4-hydroxymethyl-3-methyl-1,2,3-triazolium-1-yl)-6-deoxy starch iodine (2a) with against the tested plant threatening fungi attained 70% above at 1.0 mg/mL. It was also found that their antifungal activity profiles were dependent on the variation in alkyl chain length. As novel 1,2,3-triazolium-functionalized starch derivatives could be prepared efficiently and exhibited superduper antifungal activity, this synthetic strategy might provide an effective way and notion to prepare novel antifungal biomaterials. [ABSTRACT FROM AUTHOR]