N,N-二羧甲基壳聚糖的制备及其盐的抑菌作用研究

Study on Preparation and Bacteriostasis of N,N-Dicarboxymethylchitosan and Its Salts

制备了N,N-二羧甲基壳聚糖及其锌、银、铜盐,并考察了其抑菌作用。首先通过壳聚糖和单氯乙酸的取代反应制备了水溶性的高取代度的N,N-二羧甲基壳聚糖,然后采用分光光度法和电位滴定法测定其等电点和取代度,并制备了N,N-二羧甲基壳聚糖的锌、银、铜盐。采用分光光度法考察了它们对金黄色葡萄球菌、大肠埃希氏菌的抑菌作用,并与化学抑菌剂苯甲酸钠进行了比较。N,N-二羧甲基壳聚糖的等电点和取代度分别为2.5和1.99,N,N-二羧甲基壳聚糖的锌、银、铜盐的水溶液具有和同浓度的苯甲酸钠相当的抑菌作用,表明N,N-二羧甲基壳聚糖的锌、银、铜盐具有较好的抑菌作用。

N,N-Dicarboxymethylchitosan and its zinc,silver,copper salts were prepared and their bacteriostasis were studied.Firstly,a water-soluble N,N-dicarboxymethylchitosan with high degree of substitution was obtained by reaction of chitosan with monochloroacetic acid,and its zinc,silver,copper salts were prepared.The isoelectric point and degree of substitution were determined by spectrophotometry and potentiometric titration.Then the antimicrobial activities of N,N-dicarboxymethylchitosan and its zinc,silver and copper salts in aqueous solution against Escherichia coli and Staphylococcus aureus,were determined,and compared with that of sodium benzoate.The isoelectric point and degree of substitution of N,N-dicarboxymethylchitosan was 2.5 and 1.99,respectively.The results showed that the zinc,silver,copper salts of N,N-dicarboxymethylchitosan had good antibacterial effects on Staphylococcus aureus and Escherichia coli,which were comparable to sodium benzoate.