Synthesis of a quaternary ammonium derivative of chito-oligosaccharide as antimicrobial agent for cellulosic fibers

A derivative of chito-oligosaccharide (COS), N-(2-hydroxyl)propyl-3-trimeth yl ammonium chito-oligosaccharide chloride (HTACC), was synthesized using a reaction of glycidyltrimethylammonium chloride (GTMAC) and COS prepared by depolymerization of a fully deacetylated chitosan. COS and HTACC were appl ied to the cotton fabrics with a pad-dry-cure process using the reaction be tween the hydroxyl group of cellulose and terminal aldehyde group in COS an d HTACC. Their minimum inhibition concentration (MIC) was evaluated, and th e antimicrobial activity and durability to laundering of cotton fabrics tre ated with them were compared. The complete substitution of NH2 groups in CO S with GTMAC was obtained at a 4 : 1 mol ratio of GTMAC to NH2 in 18 h at 8 0 degrees C under the presence of acetic acid. MIC values of the 1.04 DS of HTACC and COS were 50 and 400 mu g/mL, respectively. A cotton fabric treat ed with 0.2% of HTACC and 1.8% of COS exhibited 100% reduction of bacteria. At the 50th laundering cycle, 0.3% of HTACC and 2.4% of COS indicated 100% bacterial reduction. (C) 2000 John Wiley & Sons, Inc.