Table of Contents
International Journal of Carbohydrate Chemistry
Volume 2016 (2016), Article ID 6046232, 10 pages
Research Article

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

1Department of Pesticide Chemistry and Technology, Faculty of Agriculture, Alexandria University, El-Shatby, Alexandria 21545, Egypt
2Department of Plant Protection, Faculty of Agriculture, Damanhour University, Damanhur 22516, Egypt

Received 29 June 2016; Revised 15 September 2016; Accepted 28 September 2016

Academic Editor: Shin-ichiro Shoda

Copyright © 2016 Mohamed E. I. Badawy and Entsar I. Rabea. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


Five products of -(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.