Synthesis and antibacterial activity of water-soluble chitin derivatives

Diethylaminoethyl-chitin (DEAE-chitin) was synthesized by introducing DEAE groups onto the C(6)-OH in chitin. DEAE-chitin was N-deacetylated by heating in aqueous 10% sodium hydroxide containing sodium borohydride to prepare the diethylaminoethyl-chitosan (DEAE-chitosan). In addition, DEAE-chitin was quaternized with ethyl halide to produce triethylaminoethyl-chitin (TEAE-chitin). Their antibacterial activities were evaluated by using colony count against staphylococcus aureus and E.scherichia coli by means of shake flask method. The antibacterial activity was found to increase in order of DEAE-chitin, DEAE-chitosan, TEAE-chitin. DEAE-chitin was hydrolyzed by enzymes to investigate the effect of molecular weight on its antibacterial activities. The antibacterial activity was dependent on the structure, particularly on the molecular weight of chitin derivatives. (C) 1997 by John Wiley & Sons, Ltd.