Abstract：
In this study, three types of dodecyl chitosan quaternary ammonium salts, each with different spacer groups were synthesized. These chitosan derivatives are N\',N\'-dimethyl-N\'-dodecyl-ammonium chloride-N-amino-acetyl chitosan (DMDAC), N\'-dodecyl-N-isonicotinyl chitosan chloride (DINCC) and N\',N\'-dimethyl-N\'-dodecyl-ammonium chloride-N-benzoyl chitosan (DMDBC). The synthesized products were characterized using Fourier transform infrared spectrometers, nuclear magnetic resonance, thermogravimetric analysis, and elemental analysis. The antibacterial and antibiofilm activities against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) were investigated. The experimental results indicated that the introduction of hydrophobic groups of spacer groups could enhance the antibacterial and antibiofilm activities of the chitosan derivatives. The antibacterial rates of the chitosan derivatives were over 90 % for both E. coli and S. aureus at a concentration of 0.5 mg/mL. The chitosan derivatives removed >50 % of the mature biofilm of E. coli and over 90 % of the mature biofilm of S. aureus at a concentration of 2.5 mg/mL. Further, the synthesized chitosan derivatives were determined to be non-toxic to L929 cells. Among them, DMDBC exhibited the most promising overall performance and show potential for wide-ranging applications in food preservation, disinfectants, medical, and other fields.
摘要：
在这项研究中,三种类型的十二烷基壳聚糖季铵盐，每个具有不同的间隔基团的合成。这些壳聚糖衍生物是N'，N'-二甲基-N'-十二烷基-氯化铵-N-氨基-乙酰壳聚糖(DMDAC),N\'-十二烷基-N-异烟碱基壳聚糖氯化物（DINCC）和N\'，N'-二甲基-N'-十二烷基-氯化铵-N-苯甲酰基壳聚糖(DMDBC)。利用傅里叶变换红外光谱仪对合成产物进行了表征,核磁共振,热重分析,和元素分析。对大肠杆菌的抗菌和抗生物膜活性（E.大肠杆菌)和金黄色葡萄球菌(S.金黄色葡萄球菌)进行了调查。实验结果表明，在间隔基中引入疏水基团可以增强壳聚糖衍生物的抗菌和抗生物膜活性。在0.5mg/mL的浓度下,壳聚糖衍生物对大肠杆菌和金黄色葡萄球菌的抗菌率都超过90%。壳聚糖衍生物以2.5mg/mL的浓度除去>50%的大肠杆菌的成熟生物膜和超过90%的金黄色葡萄球菌的成熟生物膜。Further,合成的壳聚糖衍生物被确定为对L929细胞无毒。其中,DMDBC表现出最有希望的整体性能，并显示出在食品保存中广泛应用的潜力，消毒剂,medical,和其他领域。
