O-（4-双胍基苯甲酰基）壳聚糖盐酸盐的制备及其抗菌活性

摘要

Biguanidinylated chitosans having antibacterial activities were prepared through acylation between aroyl chloride with biguanidinyl group and chitosan.para-Biguanidinyl benzoyl chloride was prepared through the reaction between para-biguanidinyl benzonic acid hydrochloride and SOCl2.O-（4-Biguanidinyl benzoyl） chitosan hydrochloride（p-BGBC） was obtained through the condensation reaction of para-biguanidinyl benzoyl chloride with chitosan using MeSO3H-DMSO as reaction medium.The stru-cture,molecular weight and degree of substitution（DS） of p-BGBC were characterized by FT-IR and 1H-NMR or determined by GPC and element analysis,respectively.The minimum inhibition concentrations（MIC） of p-BGBC against Staphylococcus aureus（S.aureus） and Escherichia coli（E.coli） were determined by agar plate method.The results indicated that the MIC value of p-BGBCs against S.aureus was varied from 32 μg/mL to 8 μg/mL with the DS increased from 16.2% to 44.7% while that against E.coli was varied from 64 μg/mL to 16 μg/mL.When the DS of p-BGBC achieved or exceeded 36.8%,its antibacterial activities against S.aureusand and E.colithe were higher than that of Bromo-Geramium.The introduction of biguanidinyl into the chitosan could improve its antibacterial activities obviously,and the increase of DS would result in the improvement of antibacterial activities of p-BGBC.%通过壳聚糖与含双胍基结构的芳酰氯反应,得到具有抗菌活性的双胍基化壳聚糖衍生物。利用对双胍基苯甲酸盐酸盐与氯化亚砜的反应,得到盐酸对双胍基苯甲酰氯后,再在甲烷磺酸-二甲基亚砜（MeSO3H-DMSO）介质中与壳聚糖进行缩合反应,得到了O-（4-双胍基苯甲酰基）壳聚糖盐酸盐（p-BGBC）。用FT-IR、1H-NMR、GPC和元素分析法分别表征了产物的结构、重均分子量（Mw）和胍基化度（DS）。用琼脂平板法测定了p-BGBC对金黄色葡萄球菌（S.aureus）和大肠杆菌（E.coli）的最小抑菌浓度（MIC）。结果表明：当p-BGBC的DS从16.2%提高至44.7%时,其对S.aureus的MIC从32μg/mL降至8μg/mL,对E.coli的MIC从64μg/mL降至16μg/mL;DS≥36.8%的p-BGBC对S.aureus和E.coli的抗菌活性已经超过苯扎溴铵。壳聚糖经酰基化改性引进双胍基结构后,得到的p-BGBC的抗菌性能明显改善,且其抗菌活性随DS的提高而增强。