Novel triazolyl-functionalized chitosan derivatives with different chain lengths of aliphatic alcohol substituent: Design, synthesis, and antifungal activity.

Chemical modification of chitosan is increasingly studied for its potential of providing new application for chitosan. Here, we modify chitosan at its primary hydroxyl via 'click chemistry', and a group of novel water soluble chitosan derivatives with substituted 1,2,3-triazolyl group were designed and synthesized. Aliphatic alcohols with different lengths were used as functional dendrons to improve the antifungal activity of chitosan derivatives. Meanwhile, their antifungal activity against two kinds of phytopathogens was estimated by hypha measurement in vitro. All the chitosan derivatives exhibited excellent activity against tested fungi. It is found that the antifungal activity of chitosan derivatives against the tested fungi increases with augment in the chain length of straight aliphatic alcohols. And the hydrophobic moiety (alkyl) at the periphery of the synthesized chitosan derivatives tends to affect their antifungal activity.