N-双胍-O-季铵化壳聚糖衍生物的制备及其抑菌性能的研究

发布时间：2018-03-10 06:11

  本文选题：壳聚糖　切入点：双胍盐　出处：《华中农业大学》2015年硕士论文　论文类型：学位论文

【摘要】：壳聚糖以其良好的生物相容性和生物活性在微生物抑菌方面备受关注,然而抑菌性能不佳限制了其开发应用范围。文献报道壳聚糖所带正电荷越多其抑菌性能越强,本文以增加壳聚糖所带正电荷为目标,在壳聚糖上引入双胍和季铵两种基团,并合理简化合成步骤,得到带有不同正电荷的N-双胍壳聚糖和N-双胍-O-季铵化壳聚糖衍生物,研究其对常见的致病菌的抑菌性能和规律,并将其运用于奶牛子宫内膜炎的体外评价。1.研究溶解条件、反应温度、时间、溶液p H值、投料比对产率的影响优化后最佳条件为20℃酸性条件下溶解,70℃下p H值为5时加入2倍摩尔比的双氰胺进行胍基化反应4h,80℃下p H值为9时加入1倍摩尔比的CTA进行季铵化反应12h。温度和溶液的p H值对反应影响较大,温度过高壳聚糖易分解,非适宜p H下,副产物较多、产率低。2.研究分子量、浓度、高温等因素对壳聚糖衍生物抑菌性能的影响实验研究表明,壳聚糖分子量越小,其抑菌性能越强;增加壳聚糖的浓度,其抑菌性能明显增强,本文抑菌试验中适宜样品浓度为0.1mg/ml;CS、N-双胍化CS、N-双胍-O-季铵化CS对大肠杆菌K88、金黄色葡萄球菌、沙门氏菌均具有良好的抑菌效果且依次增强,提高样品浓度能够明显增强抑菌性能;高温灭菌并没有降低壳聚糖及其衍生物的抑菌性能。结果证明,增加壳聚糖所带正电荷能够有效的增强其抑菌性能;本样品适合使用高温灭菌法;金黄色葡萄球菌对壳聚糖衍生物敏感,提高浓度能够有效的提高其抑菌效果。3.研究壳聚糖衍生物对奶牛子宫内蜡样芽孢杆菌和混菌的抑菌性能实验研究表明,以某奶牛场中患有子宫内膜炎的牛子宫内分离出来的临床单菌-蜡样芽孢杆菌和直接提取出来的混合致病菌为菌种,CS、N-双胍化CS、N-双胍-O-季铵化CS对其抑菌效果依次增强;当菌的种类增加时壳聚糖衍生物的整体抑菌率会下降。
[Abstract]:Chitosan has attracted much attention because of its good biocompatibility and bioactivity. However, its poor bacteriostatic performance limits its development and application. It is reported in the literature that the more the positive charge of chitosan is, the stronger its bacteriostatic activity is. In order to increase the positive charge of chitosan, biguanidine and quaternary ammonium groups were introduced into chitosan, and the synthetic steps were reasonably simplified to obtain N-biguanidine chitosan and N-biguane-O-quaternary ammonium chitosan derivatives with different positive charges. To study the bacteriostasis and its regularity of common pathogenic bacteria, and to apply it to the evaluation of cow endometritis in vitro. 1. To study the dissolution conditions, reaction temperature, reaction time, pH value of solution. Effect of feed ratio on yield the optimum conditions are as follows: dissolved at 70 鈩，

本文编号：1592100