Preparation of substituted quaternized arylfuran chitosan derivatives and their antimicrobial activity.

Heterocyclic modification of chitosan has been achieved through the formation of a Schiff base intermediate by the reaction of chitosan with substituted arylfurfural. The Schiff bases were further reacted with 10% sodium borohydride followed by reaction with methyl iodide to get the quaternized products. The formation of the Schiff bases and quaternized derivatives has been confirmed by elemental analysis, FTIR, (1)H NMR and UV-vis spectroscopy. The compounds are also characterized by thermo-gravimetric analysis. The parent compound and quaternized derivatives were compared for their antibacterial and antifungal activity. The results indicated that quaternized derivatives possess better inhibitory property than chitosan. Further this study confirms that heterocyclic aromatic substituent containing 'Cl' and 'NO2' are effective in enhancing the antimicrobial activity of Chitosan.