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《理化检验(化学分册)》2015,(5)
<正>羧甲基壳聚糖是壳聚糖的重要水溶性衍生物之一,具有良好的保湿性、乳化性、成膜性、抗菌性、络合性和安全无毒性等优点,是一种在工业、农业、食品、环保和医药等领域有广泛应用的两性醚聚合物[1-3]。取代度(DS)和脱乙酰度(DD)是影响羧甲基壳聚糖质量和化学性质的两个重要参数,-COONa型体分布系数则是决定其水溶性的另一 相似文献
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壳聚糖是一种可再生的天然碱性多糖,具有多种优良的特性。但是,由于壳聚糖本身的溶解性很差,只能溶解在一些稀酸中,这就在一定程度上限制了其进一步的研究与应用。因此,通过修饰改性提高其已有功能、赋予新的功能是壳聚糖重要的研究领域。其中,通过磷酸化或磷酰化改性是壳聚糖改性研究的方向之一。本文综述了在壳聚糖链上引入含磷/膦基团合成壳聚糖含磷衍生物的研究进展;介绍并讨论了壳聚糖含磷衍生物的合成及纯化方法;对壳聚糖含磷衍生物结构、性能及表面形貌的表征进行了详细的阐述;对壳聚糖含磷衍生物的应用进行了总结,并展望了壳聚糖含磷衍生物未来的应用前景。 相似文献
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壳聚糖是一种新型高分子功能材料,自身具有优良的生物性能.为克服其溶解性较差等缺陷,扩大其应用范围,常采用物理和化学的手段对壳聚糖改性,以改善其物理、化学性能,本文介绍了自2000年以来国内外关于壳聚糖物理和化学改性方面的最新研究进展,阐释了改性途径以及对改性后所得衍生物的相关表征.主要涉及到壳聚糖的烷基化、酰化以及接枝化改性等途径,并列表比较了以上各种手段的改性效果.本文的下篇<壳聚糖改性技术的新进展Ⅱ.交联化、季铵盐化、羧基化改性以及其低聚糖衍生物>将继续介绍基于壳聚糖的其它改性手段的最新进展. 相似文献
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羧甲基壳聚糖对亚铁离子的吸附 总被引:12,自引:0,他引:12
壳聚糖是由甲壳素经脱乙酰基后得到的一种天然高分子氨基多糖 ,它是金属离子的良好配体 ,其配合物在工业、农业、食品、环保、医药等方面的应用已有许多研究 [1~ 4 ] .脱乙酰基后的壳聚糖溶解性有很大改善 ,但仍只能溶于酸或酸性水溶液 ,限制了它的推广应用 .通过化学改性的羧甲基壳聚糖 ( CMCS)具有良好的水溶性、保湿性、乳化性 ,其分子中含有— OH、— NH2 、—COOH等基团 ,能有效络合金属离子 [5] .人体对壳聚糖 -亚铁络合物的吸收远远大于传统的 Fe SO4 药物 [6 ] ,壳聚糖及其衍生物与 Fe2 的络合物有可能用于治疗缺铁性贫血 … 相似文献
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疫苗佐剂能够增强机体对抗原的免疫应答反应或改变免疫应答反应类型,延长疫苗在体内作用时间,提高疫苗效力。壳聚糖能有效地将疫苗递送到靶抗原递呈细胞或组织,激活抗原提呈细胞,诱导产生免疫应答,促进Th1/Th2应答反应的平衡,因此,壳聚糖作为疫苗佐剂具有一定的潜力。为了解决壳聚糖在中性和碱性溶液中溶解性差,以及进一步提高其黏膜黏附性和靶向性等问题,通过对壳聚糖进行化学改性,生成一系列壳聚糖衍生物,提高其佐剂性能。本论文就近年来有关壳聚糖及其衍生物作为疫苗佐剂和递送系统在疫苗中的应用进行了综述,总结并提出了壳聚糖及其衍生物在疫苗佐剂应用领域所面临的问题以及其未来的发展方向,使读者对其有全面的了解。 相似文献
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Wei-Yan Quan Song-Zhi Kong Si-Dong Li Hua-Zhong Liu Qian-Qian Ouyang Yong-Mei Huang Hui Luo 《Molecules (Basel, Switzerland)》2021,26(2)
Chitosan is the only cationic polysaccharide found in nature. It has broad application prospects in biomaterials, but its application is limited due to its poor solubility in water. A novel chitosan derivative was synthesized by amidation of chitosan with 18β-glycyrrhetinic acid and sialic acid. The chitosan derivatives were characterized by Fourier transform infrared spectroscopy, thermogravimetric analysis, and measurement of the zeta potential. We also investigated the solubility, cytotoxicity, and blood compatibility of chitosan derivatives. 18β-glycyrrhetinic acid and sialic acid could be grafted onto chitosan molecular chains. The thermal stability of the synthesized chitosan derivatives was decreased and the surface was positively charged in water and phosphate-buffered saline. After chitosan had been modified by 18 β-glycyrrhetinic acid and sialic acid, the solubility of chitosan was improved greatly in water and phosphate-buffered saline, and percent hemolysis was <5%. Novel amphiphilic chitosan derivatives could be suitable polymers for biomedical purposes. 相似文献
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Chitosan is a biodegradable and biocompatible polysaccharide obtained by partial deacetylation of chitin. This polymer has been gaining increasing popularity due to its natural origin, favorable physicochemical properties, and multidirectional bioactivity. In agriculture, the greatest hopes are raised by the possibility of using chitosan as a biostimulant, a plant protection product, an elicitor, or an agent to increase the storage stability of plant raw materials. The most important properties of chitosan include induction of plant defense mechanisms and regulation of metabolic processes. Additionally, it has antifungal, antibacterial, antiviral, and antioxidant activity. The effectiveness of chitosan interactions is determined by its origin, deacetylation degree and acetylation pattern, molecular weight, type of chemical modifications, pH, concentration, and solubility. There is a need to conduct research on alternative sources of chitosan, extraction methods, optimization of physicochemical properties, and commercial implementation of scientific progress outcomes in this field. Moreover, studies are necessary to assess the bioactivity and toxicity of chitosan nanoparticles and chitosan conjugates with other substances and to evaluate the consequences of the large-scale use thereof. This review presents the unique properties of chitosan and its derivatives that have the greatest importance for plant production and yield quality as well as the benefits and limitations of their application. 相似文献
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聚乙二醇化壳聚糖的制备及其应用研究进展 总被引:1,自引:0,他引:1
聚乙二醇(PEG)是一种具有无毒、亲油亲水、高生物相容和无免疫原性等特点的化合物。将聚乙二醇结构引入壳聚糖(CTS)糖链中得到的聚乙二醇化壳聚糖,不但保持了CTS的天然性和优良生物降解等特性,还具有更好的水溶性和对有机化合物的结合能力。通过对CTS进行聚乙二醇化改性,可进一拓展其应用领域。本文结合近20年国内外PEG改性CTS的研究特点,围绕PEG改性CTS的制备及其在药物负载与控制释放、组织工程、抗菌材料、生物活性物传递和环境保护等领域的应用进行了总结,并展望其未来的发展趋势。 相似文献
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《Analytical letters》2012,45(17):2635-2656
Chitosan is one of the most abundant natural polysaccharide in nature. Due to its unique properties, chitosan has fascinated the scientific community since its discovery. When modified with other materials and combined with magnetic particles, the resulting composite material, a magnetic chitosan derivative, is provided with three significant characteristics. First, chitosan has excellent properties for preconcentration/extraction, such as adsorption and chelating effects, low cost, and nontoxicity. Second, new functional groups have enhanced the properties of chitosan that include water solubility, stability, recyclability, and enhanced adsorption capacity. Finally, due to the efficient and fast adsorption processes, as well as simple and convenient magnetic separation, the magnetic adsorbents greatly reduce the time of sample handling. In this article, recent synthesis and modification methods of magnetic chitosan derivatives are reviewed along with some applications in analytical separations. 相似文献
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健康生活方式特别强调食物质量,多酚在这方面发挥了关键作用。槲皮素是一种天然多酚,是多种植物性食品中发现最丰富的类黄酮类化合物之一。槲皮素是天然的抗氧化剂,可以保护细胞免受自由基造成的损害。槲皮素是一种亲脂性化合物,能够穿过细胞膜,可调节众多与疾病进展、化学预防有关的细胞内和细胞外信号通路。槲皮素具有广泛的药理活性,抗炎、抗菌、抗癌和预防心脑血管疾病,但是它低溶解度和生物利用度限制了在临床上的应用。对槲皮素的结构进行优化修饰获得了溶解性能好、生物利用度高、活性明显改善、抗癌活性增强的槲皮素衍生物。综述了近年来槲皮素酯衍生物的研究进展,为槲皮素衍生物的进一步开发提供参考。 相似文献