The influence of chemical structure on the antimicrobial activities of thiosemicarbazone-chitosan

We have previously reported the preparation of acetyl and benzoyl phenyl-thiosemicarbazone derivatives of chitosan and their antimicrobial activities. The purpose of this study was to further assess the relationship between chemical structure and antimicrobial activity of chloracetyl phenyl-thiosemicarbazone-chitosan. Ten new chloracetyl phenyl-thiosemicarbazone-chitosans were prepared, and their structures were characterized using FT-IR and elemental analysis. The synthesized compounds were tested against four species of bacteria and four crop-threatening pathogenic fungi. Different molecular weights and concentrations were evaluated. The antifungal activities of the synthesized compounds were related to the positive polarity of the N₄ atom and the distribution of the electron atmosphere in the C=S group. All chitosan compounds had inhibitory effects when tested with bacteria. The minimum MIC and MBC with Escherichia coli were 7.03 and 56.25 μg mL^?1, respectively.