糠醛改性O-季铵化壳聚糖衍生物的合成及其抗菌性能

在制备水溶性较好的O-季铵化壳聚糖基础上，进一步与糠醛反应制备O-季铵化-N-呋喃亚甲基壳聚糖席夫碱及还原产物O-季铵化-N-呋喃亚甲基壳聚糖衍生物，用FTIR、1H NMR、EA（元素分析）、TG（热重分析）对产物进行表征。测定产物的最低抑菌浓度和抑菌率，并与O-季铵化-N-苯亚甲基壳聚糖席夫碱的抑菌效果进行比较。结果表明，产物对革兰氏阳性菌S.aureus的抗菌效果优于革兰氏阴性菌E. coli，在pH值5.5的条件下抗菌效果优于pH 值7.2。并且O-季铵化-N-呋喃亚甲基壳聚糖的抗菌效果>O-季铵化-N-呋喃亚甲基壳聚糖席夫碱>O-季铵化-N-苯亚甲基壳聚糖席夫碱 > O-季铵化-壳聚糖。研究表明，含呋喃杂环的壳聚糖衍生物的抗菌活性明显优于不含杂环的壳聚糖衍生物。

Synthesis and antibacterial properties of furfural modified chitosan derivatives

Shiff bases and derivates of O-quaternized-N-furan methylene chitosan were synthesized by water-soluble O-quaternized chitosan and furfural. The products were characterized by FTIR、1H NMR、EA(elemental analysis)，TG(thermogravimetric analysis) respectively. The minimum inhibitory concentration and the bacteriostasis rate of the obtained chitosan derivatives were tested，and compared with those of the O-quaternized-N-benzylidene chitosan shiff base. The results showed that the antibacterial effect of series products against gram positive bacteria S. aureus was stronger than that against gram negative bacteria E. coli. The antibacterial effect the under condition at pH=5.5 was stronger than that at pH=7.2. The order of antibacterial effect was as following：O-quaternized-N- furan methylene chitosan>O-quaternized-N-furan methylene chitosan shiff base>O-quaternized-N-benzylidene chitosan shiff base> O-quaternized chitosan. The results indicated that the antibacterial activity of chitosan derivatives with furan heterocyclic groups was obviously better than that without heterocyclic groups.