Synthesis and Antimicrobial Activity of N-(6-Carboxyl Cyclohex-3-ene Carbonyl) Chitosan with Different Degrees of Substitution

[摘要] Five products of N-(6-carboxyl cyclohex-3-ene carbonyl) chitosan as antimicrobial agents were prepared by reaction of chitosan with tetrahydrophthalic anhydride (THPA) at different degrees of substitution (DS). The antimicrobial activity was evaluated against four plant bacteria and eight fungi. The results proved that the inhibitory property and water solubility of the synthesized chitosan derivatives, with increase of the DS, exhibited a remarkable improvement over chitosan. The product with a DS of 0.40 was the most active one with MIC of 510, 735, 240, and 385?mg/L against Erwinia carotovora, Ralstonia solanacearum, Rhodococcus fascians, and Rhizobium radiobacter, respectively, and also in mycelial growth inhibition against Alternaria alternata (EC50 = 683?mg/L), Botrytis cinerea (EC50 = 774?mg/L), Botryodiplodia theobromae (EC50 = 501?mg/L), Fusarium oxysporum (EC50 = 500?mg/L), F. solani (EC50 = 260?mg/L), Penicillium digitatum (EC50 = 417?mg/L), Phytophthora infestans (EC50 = 298?mg/L), and Sclerotinia sclerotiorum (EC50 = 763?mg/L). These compounds based on a biodegradable and biocompatible chitosan could be used as potentially antimicrobial agents in crop protection instead of hazardous synthetic pesticides.

[学科分类] 有机化学