Understanding effects of sulphation of physical and chemical characteristics of polysaccharides: new renewable biopolymers for personal care products

了解硫酸化对多糖物理和化学特性的影响：用于个人护理产品的新型可再生生物聚合物

• 批准号: 1945155
• 金额: --
• 依托单位: University of Liverpool
• 依托单位国家: 英国
• 项目类别: Studentship
• 财政年份: 2017
• 资助国家: 英国
• 起止时间: 2017 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=studentship-1945155
• 关键词: Understanding; effects; sulphation; physical; chemical

Carbohydrates, derived from plant and animal sources, have many natural and commercial applications arising from their physical, chemical and interaction properties. As carbohydrate modifications have resulted in observable differences to these properties, modified samples have been used in various applications from pharmaceutical agents to emulsions and food components. Several carbohydrates will be used during this project as representative linear uncharged, linear charged and branched uncharged examples. The project will target improving NMR-based carbohydrate analysis methods, the generation of novel carbohydrate modifications and modification methods, and the measurement of the physical, chemical and interaction properties of modified samples.Carbohydrate characterisation enables the starting material structure to be ascertained and any modification and interaction sites determined. Nuclear Magnetic Resonance (NMR) is the most powerful and versatile structural analysis method for carbohydrates and requires methodological improvements to allow individual atom assignments to be made. Combining this with additional methods, such as size exclusion chromatography and mass spectrometry, as well as recent developments in the field of carbohydrate NMR via diffusion spectroscopy, will allow comparison of those methods that are able to separate of distinguish the different sized fractions, and assist structural characterisation. These combined methods will also allow the repeating unit distribution the frequency with which these units occur to be determined.Modifications have demonstrably affected the physical chemical and interaction properties of the carbohydrates used in this project. A panel of modifications focusing on the addition of charges to the carbohydrate via sulphation, oxidation to carboxyl groups but also reduction, will be performed on each of the carbohydrates selected. The analysis of modified products generated will be performed using the NMR-based structural analysis method developed above with the precise location of modification sites determined. Additional factors that could influence modification sites will also be investigated to determine whether specific atomic positions can be targeted when a novel method is developed rather than that achieved traditionally.Previous carbohydrate modifications have been investigated in terms of their effect on the physical and chemical properties of the samples. The principal focus for these properties will be on rheological measurements, owing to potential application in the commercial sector by our industrial partner. Other physical and chemical properties which are important to study include solubility, viscosity, molecular mobility, deposition and cleaning. Many of these properties could be measured during a placement period in our commercial partner's laboratories as well as on the University's NMR spectrometers.In addition to the effect that carbohydrate modification has on the physical and chemical properties of the resultant sample, effects are also evident in the ability of the carbohydrate to interact with other compounds that it may encounter. The effect that modifications have on these interactions will also be studied using several test systems for proteins, other carbohydrates and/or surfactant molecules. In certain cases, the study of interaction variability, using structural analysis methods, will be coupled with biological assays. Studying these interactions structurally will require the combination of NMR with other common methods, such as isothermal titration calorimetry and circular dichroism or differential scanning fluorimetry/calorimetry, to generate kinetics and protein stability data respectively when the modified polysaccharide is added.

碳水化合物来源于植物和动物，由于其物理、化学和相互作用性质而具有许多天然和商业应用。由于碳水化合物改性导致这些性质的可观察差异，改性样品已用于从药剂到乳液和食品组分的各种应用中。在这个项目中，将使用几种碳水化合物作为代表性的线性不带电，线性带电和支链不带电的例子。该项目的目标是改进基于NMR的碳水化合物分析方法，开发新的碳水化合物修饰和修饰方法，以及测量修饰样品的物理、化学和相互作用性质。碳水化合物表征可以确定起始材料的结构，并确定任何修饰和相互作用位点。核磁共振（NMR）是碳水化合物最强大和最通用的结构分析方法，需要改进方法以进行单个原子的分配。将其与其他方法相结合，例如尺寸排阻色谱法和质谱法，以及通过扩散光谱法在碳水化合物NMR领域的最新发展，将允许比较那些能够分离或区分不同尺寸级分的方法，并有助于结构表征。这些结合的方法也将允许重复单元分布的频率与这些单元出现被determined.Modifications已被证明影响的物理化学和相互作用特性的碳水化合物在这个项目中使用。将对所选的每种碳水化合物进行一组修饰，重点是通过硫酸化、氧化为羧基以及还原向碳水化合物添加电荷。将使用上述开发的基于NMR的结构分析方法对生成的改性产物进行分析，并确定改性位点的精确位置。可能影响修饰位点的其他因素也将被研究，以确定当开发新方法而不是传统方法时，是否可以靶向特定的原子位置。先前的碳水化合物修饰已经研究了它们对样品的物理和化学性质的影响。由于我们的工业合作伙伴在商业领域的潜在应用，这些特性的主要重点将是流变测量。其他重要的物理和化学性质包括溶解度、粘度、分子流动性、沉积和清洁。这些性质中的许多可以在我们的商业合作伙伴的实验室以及大学的NMR光谱仪上进行测量。除了碳水化合物改性对所得样品的物理和化学性质的影响外，碳水化合物与可能遇到的其他化合物相互作用的能力也很明显。还将使用蛋白质、其他碳水化合物和/或表面活性剂分子的几种测试系统研究修饰对这些相互作用的影响。在某些情况下，使用结构分析方法进行的相互作用变异性研究将与生物测定相结合。从结构上研究这些相互作用将需要结合NMR与其他常用方法，如等温滴定量热法和圆二色性或差示扫描荧光法/量热法，以产生动力学和蛋白质的稳定性数据时，分别加入改性多糖。