中文摘要：

以阿魏酸（FA）为底物,利用漆酶作为催化剂催化壳聚糖与阿魏酸接枝反应。对FA-壳聚糖接枝产物分别进行线性电位滴定、红外光谱检测和热重分析,确定产物的接枝率和结构的变化,并进一步对其抗氧化性和抑菌性能进行研究。结果表明,FA-壳聚糖的接枝率约为11.4%;在漆酶催化过程中阿魏酸的酚羟基与壳聚糖上的氨基参与反应,FA与壳聚糖之间可能受到了席夫碱（Schiff）的修饰;与壳聚糖原样相比,FA-壳聚糖衍生物的热稳定性也得到了提高;FA-壳聚糖衍生物对DPPH和ABTS自由基的清除率的IC50值分别为1.88和0.61mg/mL,表明FA-壳聚糖的抗氧化性能得到改善;抑菌性能检测得出在浓度为1mg/mL时FA-壳聚糖较壳聚糖原样对大肠杆菌和沙门氏菌的抑菌圈分别提高了1.5和1.3mm,在浓度为5mg/mL时FA-壳聚糖较壳聚糖原样对枯草芽孢杆菌和金黄色葡萄球菌的抑菌圈分别提高了2.5和2.0mm。

英文摘要：

Chitosans were grafted with ferulic acid （FA）by laccase.The reactions were performed with chitosan under an eco-friendly procedure,in a system at 40 ℃,in phosphate buffer （100 mmol/L,pH 6.5）.The linear potentiometric titration,FT-IR and TGA were used to characterize the graft ratio,structural changes of FA-chitosan and its antioxidant and antibacterial activity.The results show that the graft ratio of FA-chitosan was 1 1 .4%.In this catalysis process,phenolic hydroxyl in ferulic acid reacted with amino-group in the chitosan initiated by laccase,confirming the occurrence of a Schiff-base reaction.The thermal stability of FA-chitosan derivative have been improved;meanwhile,the antioxidant and antibacterial property of FA-chitosan have been improved too;IC50 were 1.88,0.61 mg/mL for DPPH and ABTS·＋ scavenging,respectively.When com-pared with chitosan,the inhibition zone for FA-chitosan against E.coli and S.enterica were increased by 1 .5 and 1 .3 mm at the concentration of 1 mg/mL,against Bacillus subtilis and Staphylococcus aureus were in-creased by 2.5 and 2.0 mm at the concentration of 5 mg/mL.