STRUCTURE FUNCTION RELATIONSHIPS IN POLYSACCHARIDES AND POLYSACCHARIDE-BLENDS

这个子项目是利用资源的许多研究子项目之一。 由NIH/NCRR资助的中心拨款提供。对子项目的主要支持 子项目的首席调查员可能是由其他来源提供的， 包括美国国立卫生研究院的其他来源。为子项目列出的总成本可能 表示该子项目使用的中心基础设施的估计数量， 不是由NCRR赠款提供给次级项目或次级项目工作人员的直接资金。 多糖是生物体中普遍存在的一类独特的生物聚合物。它们构成海洋甲壳类、植物、藻类和微生物的壁的结构成分。它们具有不同的化学结构，并显示出各种各样的分子排列，从而形成单螺旋、双螺旋和三螺旋的片状和螺旋状。此外，它们构成了大量的可再生资源，为人类提供了各种有益的功能，特别是在组织工程、药物载体、胶囊和保健品的控制释放等领域。尤其是其可再生性、生物降解性和生物活性等特殊性质催生了新型应用的发展。其中许多是水溶性的，能够显着改变水基溶液的功能，如食品分散体的质地增稠、胶凝、粘度、乳化、保湿和物理稳定性，并在食品、化妆品、生物医学和制药等领域找到了广泛的应用。在这方面，对多糖结构多样性和基础知识的详细了解，以及对其形状和原子水平相互作用的洞察，有助于理解和预测其宏观行为，主要与其最终用途有关。目前的建议是关于确定一些具有重要生物学意义和工业用途的多糖-多糖混合物的分子结构和堆积排列，以及它们与溶剂和溶质分子的相互作用。这项研究包括卡拉胶、玉米阿拉伯木聚糖和木聚糖组分等多糖，以及丙氨酸：葡甘聚糖黄原胶：半乳甘露聚糖黄原胶：半乳甘露糖玉米阿拉伯木聚糖：半乳甘露聚糖-卡拉胶：半乳甘露聚糖和卡拉胶-半乳甘露聚糖等二元体系。此外，我们最近的研究表明，药物分子、营养食品和维生素可以嵌入到IOTA-卡拉胶的晶格中，从而形成新型的聚合物共晶体。与表现出凝胶行为的卡拉胶相比，这些材料在水中的溶解度很高。此外，热性质表明，被包裹的分子受到卡拉胶分子的保护，不受外部扰动的影响，这些络合物具有作为控制输送载体的潜力。为了了解小分子与多糖骨架之间的内在相互作用，从而了解它们从多糖骨架中的释放情况，我们重点研究了几种聚合物共晶体的结构特征。由于食品体系中长期使用的卡拉胶、凝胶和黄原胶等多糖与小药物分子、营养食品和维生素结合使用，因此选择这些多糖作为模型样品。我们坚信，这项研究的结构结果将有助于解开多糖：药物之间的相互作用，从而开发利用多糖纤维的新型载体。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Polysaccharides comprise a distinct class of biopolymers produced universally among the living organisms. They form structural components of walls of marine crustaceans plants algae and microorganisms. They have different chemical structures and exhibit a wide variety of molecular arrangements resulting in sheets and spirals of single double and triple helices. Further they constitute a large source of renewable resources offering a variety of beneficial functionalities to mankind especially in the domain of tissue engineering drug vehicles encapsulation and controlled release of nutraceuticals to name a few. In particular their special properties such as renewability biodegrability and biological activity spawn the development of novel applications. Many of them are water soluble and are capable of significantly altering the functionality of aqueous based solutions such as texture thickening gelling viscosity emulsifying hydrating and physical stability of food dispersions and find a gamut of food cosmetic biomedical and pharmaceutical applications. In this regard a detailed understanding about the structural diversity and fundamental knowledge of polysaccharides architecture with insights about their shape and atomic level interactions aids in understanding as well as predicting their macroscopic behavior mainly related to their end-use applications. The current proposal is about determining the molecular structure and packing arrangement of a number of biologically important and industrially useful polysaccharides polysaccharide-blends and their interactions with solvent and solute molecules. The study includes polysaccharides such as iota-carrageenan kappa-carrageenan lambda-carrageenan corn arabinoxylan and psyllium and binary systems such as acetan:glucomannan xanthan:glucomannan xanthan:galactomanna corn arabinoxylan:galactomannan iota-carrageenan:galactomannan and kappa-carrageenan-galactomannan. Further our recent research demonstrates that drug molecules nutraceuticals and vitamins can be embedded in the crystalline lattice of iota-carrageenan leading to novel polymeric cocrystals. These materials are highly soluble in water compared to iota-carrageenan that displays gelation behavior. Further the thermal properties suggest that the entrapped molecules are protected by the carrageenan molecules from the external perturbations and these complexes have the potential to serve as control delivery vehicles. In order to gain knowledge about the intrinsic interactions between the small molecules with the polysaccharide backbone so as to understanding their release profile from the polysaccharide matrix we are focusing on the structural characterization of several polymeric cocrystals. The polysaccharides such as iota-carrageenan kappa-carrageenan lambda-carrageenan gellan and xanthan are chosen as model samples as they are utilized in food systems for a longtime upon FDA approval combined with small drug molecules nutraceuticals and vitamins. We strongly believe that the structural results obtained from this study would be helpful in unraveling the polysaccharide:drug interactions towards the development of novel carriers utilizing polysaccharide fibers.