Preparation of N-vanillyl chitosan and 4-hydroxybenzyl chitosan and their physico-mechanical, optical, barrier, and antimicrobial properties

• Published in: Carbohydrate polymers Vol. 87; no. 1; pp. 110 - 116
• Main Authors: Jagadish, R.S., Divyashree, K.N., Viswanath, Prema, Srinivas, P., Raj, Baldev
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier Ltd 04.01.2012; Elsevier
• Subjects: 1H NMR; 4-Hydroxy-3-methoxybenzaldehyde (vanillin); 4-Hydroxybenzaldehyde; aflatoxins; anti-infective properties; Antibiotics. Antiinfectious agents. Antiparasitic agents; Antifungal agents; Antifungal properties; Applied sciences; Aspergillus flavus; Biological and medical sciences; chemical reactions; chitosan; Chitosan derivatives; Exact sciences and technology; fungi; hydroxybenzaldehyde; Medical sciences; Natural polymers; nuclear magnetic resonance spectroscopy; Pharmacology. Drug treatments; Physicochemistry of polymers; schiff bases; Starch and polysaccharides; Tensile strength; thermal properties; vanillin; water vapor; WVTR; Chitosan derivatives; WVTR; 4-Hydroxy-3-methoxybenzaldehyde (vanillin); 1H NMR; Antifungal properties; Tensile strength; 4-Hydroxybenzaldehyde; Biological properties; Transport properties; Condensation reaction; Fungicidal effect; Mechanical properties; Experimental study; Antimicrobial agent; Thermal stability; Chemical reduction; Chemical modification; Steam permeability; Optical properties; Preparation; Oside polymer; Chitosan; Vanillin; H NMR; 4-Hydroxy-3-methoxybenzaldehyde; Benzaldehyde derivatives
• ISSN: 0144-8617; 1879-1344
• DOI: 10.1016/j.carbpol.2011.07.024

[Display omitted] ► Chitosan was chemically modified with vanillin and 4-hydroxy benzaldehyde with a degree substitution of 63% and 59%, respectively of the amino group. ► WVTR decreased by 68% in N-vanillyl chitosan and 79.59% in 4-hydroxybenzyl chitosan, respectively. ► Tensile strength improved by 17.7% in N-vanillyl chitosan and 11.11% in 4-hydroxybenzyl chitosan. ► N-vanillyl chitosan and 4-hydroxybenzyl chitosan film discs showed a marked reduction of aflatoxins produced by the fungus to 98.9% and at non-detectable levels, respectively. Chitosan derivatives such as N-vanillyl chitosan and 4-hydroxybenzyl chitosan were prepared by reacting chitosan with 4-hydroxy-3-methoxybenzaldehyde (vanillin) and 4-hydroxybenzaldehyde. Amino groups on chitosan reacts with these aldehydes to form a Schiff base intermediate, which is later on converted into N-alkyl chitosans by reduction with sodium cyanoborohydride. The chemical reaction was monitored by 1H NMR spectroscopy and the absence of aldehydic proton at 9.83ppm in NMR spectra was observed for both the modified chitosan derivatives confirming the reaction. Modified chitosan films were later prepared by solution casting method and their physico-mechanical, barrier, optical and thermal properties were studied. The results clearly indicated significant change in tensile strength, water vapour transmission rate, and haze properties of modified chitosans. Modified chitosan films were also studied for their antimicrobial activity against Aspergillus flavus. The results showed a marked reduction of aflatoxins produced by the fungus in the presence of the N-vanillyl chitosan and 4-hydroxybenzyl chitosan film discs to 98.9% and non-detectable levels, respectively.