Fucoidans are a diverse class of sulfated polysaccharides integral to the cell wall of brown algae, and due to their various bioactivities, they are potential drugs. Standardized work with fucoidans is required for structure–function studies, but remains challenging since available fucoidan preparations are often contaminated with other algal compounds. Additionally, fucoidans are structurally diverse depending on species and season, urging the need for standardized purification protocols. Here, we use ion-exchange chromatography to purify different fucoidans and found a high structural diversity between fucoidans. Ion-exchange chromatography efficiently removes the polysaccharides alginate and laminarin and other contaminants such as proteins and phlorotannins across a broad range of fucoidans from major brown algal orders including Ectocarpales, Laminariales and Fucales. By monomer composition, linkage analysis and NMR characterization, we identified galacturonic acid, glucuronic acid and O-acetylation as new structural features of certain fucoidans and provided a novel structure of fucoidan from Durvillaea potatorum with α-1,3-linked fucose backbone and β-1,6 and β-1,3 galactose branches. This study emphasizes the use of standardized ion-exchange chromatography to obtain defined fucoidans for subsequent molecular studies.

中文翻译：

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褐藻中五种硫酸化褐藻糖胶的离子交换纯化和结构表征

褐藻糖胶是褐藻细胞壁中不可或缺的多种硫酸化多糖，由于它们的各种生物活性，它们是潜在的药物。结构-功能研究需要对褐藻糖胶进行标准化工作，但由于可用的褐藻糖胶制剂经常被其他藻类化合物污染，因此仍然具有挑战性。此外，褐藻糖胶在结构上因物种和季节而异，因此需要标准化的纯化方案。在这里，我们使用离子交换色谱法纯化不同的褐藻糖胶，发现褐藻糖胶之间存在高度的结构多样性。离子交换色谱法有效去除来自主要褐藻目的广泛褐藻糖胶中的多糖藻酸盐和海带多糖以及其他污染物，例如蛋白质和根叶单宁，包括Ectocarpales、Laminariales和Fucales。通过单体组成、键联分析和核磁共振表征，我们确定了半乳糖醛酸、葡萄糖醛酸和 O-乙酰化是某些褐藻糖胶的新结构特征，并提供了具有 α-1,3-连接岩藻糖骨架和 β -1,6 和 β-1,3 半乳糖分支。本研究强调使用标准化的离子交换色谱来获得确定的褐藻糖胶，用于后续的分子研究。