共查询到17条相似文献,搜索用时 171 毫秒
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多糖的硫酸化修饰及其结构与生物活性关系研究进展 总被引:3,自引:0,他引:3
多糖是生物体内除蛋白质和核酸外又一类重要的生物活性大分子。其具有抗肿瘤、抗凝血和免疫调节活性等多种功能活性,已引起生物医学领域研究者的关注。近10年来的研究发现:硫酸化修饰可以改善多糖的诸多理化性质,显著地增强其原有生物活性,甚至使其产生新的活性。本文概述了多糖硫酸化修饰、结构分析的方法,综述了硫酸化多糖的主要生物活性以及硫酸化修饰对多糖抗肿瘤、抗病毒、抗氧化、免疫调节等生物活性的影响等相关研究进展,可为今后开展硫酸化多糖结构、活性的深入研究及应用开发提供参考。 相似文献
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研究发现并非所有的多糖都具有活性或只具有较弱的活性,其受多糖分子中化学结构的影响。因此,采取有效方法对多糖进行结构修饰是增强其生物活性和促进生物活性呈现的有效途径,其对多糖构效关系的研究及多糖产品的开发和利用具有重要的实践指导意义。目前,已掌握的结构修饰方法主要有化学修饰法、物理修饰法及生物修饰法。本文主要以这三大修饰方法为主线,从各自具体的修饰方法、原理及对多糖生物活性的影响等方面对近年来国内外多糖结构修饰的研究进行综述,其中重点介绍化学修饰的具体方法及对多糖生物活性的影响,为多糖结构修饰的深入研究与探索及糖类产品的开发与利用提供合理有价值的参考。 相似文献
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多糖分子修饰研究进展 总被引:1,自引:0,他引:1
《食品工业》2017,(5)
多糖广泛存在于自然界,是一类重要的生物大分子,具有多种生物活性。多糖结构对于其活性发挥起着极为关键的作用。多糖的结构修饰对于揭示多糖的构效关系具有重要意义。通过概述多糖接枝修饰和降解修饰的具体方法,综述了近年来运用各种方法对多糖的修饰情况,以及对其生物活性的影响等相关研究进展,可为今后开展多糖结构修饰、活性研究及进一步开发应用多糖提供参考。 相似文献
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卡拉胶(carrageenan)是一种从海洋红藻细胞壁中提取出来的多糖物质,通过1,3-β-D-吡喃半乳糖和1,4-α-D-吡喃半乳糖交替连接作为基本骨架形成的线性硫酸多糖。研究表明,卡拉胶及其分子修饰后获得的衍生物具有抗肿瘤、抗病毒、抗凝血、增强人体细胞免疫和体液免疫力等多方面生物活性。卡拉胶酶属于糖苷水解酶,通过使β-1,4糖苷键断裂来降解卡拉胶。卡拉胶硫酸酯酶又被称作卡拉胶硫酸化酶,是一种作用于卡拉胶寡糖的硫酸基使之游离出无机硫酸的酶。经研究证实,这两种酶对于卡拉胶多糖的降解具有协同作用。然而由于卡拉胶多糖结构的复杂性,人们对于卡拉胶的降解及分子修饰大多数尚未探索。现如今,随着技术的进步以及卡拉胶多糖生物活性的多样性,卡拉胶多糖的分子修饰引起了相关研究者的持续关注。作者概括了近年来卡拉胶多糖的分子修饰,重点介绍了卡拉胶酶和硫酸化酶的研究进展,进一步阐述了其修饰后的生理活性变化。 相似文献
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多糖是一种重要的生物大分子物质,具有多种生物活性。多糖的生物活性与本身的结构有着直接联系。因此,对多糖结构进行修饰,选择合适的修饰方法成为研究多糖的一个重要方向。本文主要综述了多糖的化学修饰方法及化学修饰对多糖抗肿瘤活性的影响,包括多糖的硫酸化修饰、羧甲基化修饰、酸化修饰、乙酰修饰等,并对多糖结构修饰的应用前景进行展望,以期为多糖化学修饰的深入研究与探索及糖类产品的开发与利用提供参考。 相似文献
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多糖是由多个单糖分子经脱水缩合,藉由糖苷键连接而成的天然大分子化合物,在生物中有储存能量、信息传递和组成结构的作用。多糖的理化性质受其空间结构、分子量、侧链取代基类型、数量和位置的影响。选择合适的改性方法对多糖进行分子修饰,提高其生物活性,这是研究多糖构效关系及开发多糖产品的重要途径。磷酸化多糖是多糖经特定的化学方法进行磷酸基团结构修饰制备的衍生物。本文重点阐述了酸法、磷酰氯法和磷酸盐法3种磷酸化多糖的修饰工艺和工艺条件,分析目前存在的问题,归纳了磷酸化多糖在抗氧化、抗肿瘤、抗病毒和免疫调节等方面的生物活性作用,旨在为多糖的构效研究中提供工艺参考和理论依据。 相似文献
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天然多糖因其结构稳定、分子量高、具有多种生物活性、安全性高等优点而表现出良好的乳化和增稠作用,被作为乳化剂广泛应用于食品工业。然而,多糖的高亲水性、难溶解性等特点导致其在高温、高盐等条件下乳化性能较差,限制了其广泛应用。通过对多糖进行修饰可以改变其分子量、结构、疏水性等功能特性,提升其乳化性能。本文综述了物理、化学和生物等修饰方法对多糖分子结构、乳化性能等的影响及修饰多糖在乳状液中应用的研究现状和进展,分析了目前修饰方法中存在的问题,并对未来发展趋势进行了展望,旨在为改善多糖乳化性能的进一步研究和拓宽其应用领域提供理论依据。 相似文献
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BackgroundPolysaccharides are a kind of biological macromolecular substance with multiple biological effects. Natural polysaccharides derived from plants and fungi are known as ideal raw food supplements for health food and pharmaceuticals due to their few side effects. Sulfated modification could significantly improve structure characteristics, promote bioactivities, and even add new bioactivities to polysaccharides. Thus, sulfated polysaccharides are increasingly causing more attention, as they have been proved to possess a variety of biological activities, including antioxidant, anticancer, and immunoregulatory, and anticoagulant activities. Furthermore, recent advances in synthesis, characterization and bioactivities of sulfated polysaccharides can promote its application in the food industry or pharmaceutics.Scope and approachThis paper reviewed the main methods of sulfated modification, structural changes and the bioactivities of sulfated polysaccharide derivatives. We have comprehensively discussed biological activities of sulfated polysaccharides, emphatically the effects of sulfated group, composition, functional groups, as well as their replaced position on the bioactivities of sulfated polysaccharides, in order to reveal the potential mechanism of sulfation on bioactivities of polysaccharides.Key findings and conclusionsThis paper reviewed the recent research in the sulfated modification of polysaccharides and provided future directions for research in this area. There are many methods for sulfated modification, such as chlorosulfonic acid-pyridine method, concentrated sulfuric acid method, and sulfur trioxide-pyridine method, which could improve anti-coagulant, anti-oxidative, immunoregulation, anti-tumor, and anti-virus activities of polysaccharides. Sulfated modification could change bioactivities of polysaccharides due to their effects on structure characteristics. DS, monosaccharide compositions, replaced position of sulfated groups were considered to contribute to their bioactivities promotion. Further studies are required to explore the application of sulfated polysaccharides in pharmaceutical and food industries. 相似文献
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Shijie Li Qingping Xiong Xiaoping Lai Xia Li Mianjie Wan Jingnian Zhang Yajuan Yan Man Cao Lun Lu Jiemin Guan Danyan Zhang Ying Lin 《Comprehensive Reviews in Food Science and Food Safety》2016,15(2):237-250
Polysaccharides are ideal natural resources for supplements and pharmaceuticals that have received more and more attention over the years. Natural polysaccharides have been shown to have fewer side effects, but because of their inherently physicochemical properties, their bioactivities were difficult to compare with those of synthetic drugs. Thus, researchers have modified the structures and properties of natural polysaccharides based on structure–activity relationships and have obtained better functionally improved polysaccharides. This review focuses on the major modification methods of polysaccharides, and discusses the effect of molecular modification on their physicochemical properties and bioactivities. Molecular modification methods mainly include chemical, physical, and biological changes. Chemical modification is the most widely used method; it can significantly increase the water solubility and bioactivities of polysaccharides by grafting onto other groups. Physical and biological modifications only change the molecular weight of a polysaccharide, and thereby change its physicochemical properties and bioactivities. Most of the molecular modifications bring about an increase in the antioxidant activity of polysaccharides, and among these, sulfated and acetylated modifications are very common. Furthermore, phosphorylation modification is the most common application to increase antitumor activity, and modified polysaccharides have been shown to have anti‐HIV activity as the result of sulfated modification. 相似文献
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