Preparation and Antifungal Activity Investigation of Oligochitosan-Zn2+ on Colletotrichum truncatum

Abstract EN

This study presents the structural characteristics and the antifungal efficiency of the oligochitosan-Zn2+ complexes.

Oligochitosan with the average molecular weight of ~5 kDa was effectively prepared by gamma-ray irradiation degradation of chitosan in a solution containing H2O2.

The oligochitosan-Zn2+ complexes with the different molar ratios of -NH2/Zn2+ were prepared by mixing Zn(NO3)2 into oligochitosan solution.

The resultant complexes were characterized by FTIR, XRD, UV-Vis, and ICP-AES.

The obtained results demonstrated that Zn2+ ions were stably bound with oligochitosan molecules through interacting with -OH and -NH2 groups.

The in vitro antifungal effect of oligochitosan-Zn2+ complexes was assessed against Colletotrichum truncatum, a fungus species causing anthracnose on crops.

The antifungal activity was significantly improved as the increase of Zn2+ content in the complexes.

Particularly, the antifungal efficiency of the complexes reached to 75–100% compared to that of about 12% for oligochitosan.

Thus, the addition of Zn2+ into oligochitosan strengthens its performance towards antifungal property and bring forward a new approach for progressing biobased materials for controlling plant diseases.