石莼多糖及其寡糖结构、制备及活性的研究进展

石莼多糖是石莼属海洋绿藻细胞壁的主要成分，其复杂的结构和单糖组成赋予了各种生物活性，如抗病毒、抗炎症、抗凝血、抗氧化等。但是提取得到的石莼多糖的分子量较大，存在溶解度低，生物利用率差等缺点，这很大程度地限制了石莼多糖的高值化开发与有效利用。通过降解石莼多糖得到的低分子量的寡糖产物，即石莼寡糖，不仅能够非常好地保留石莼多糖的多种生物活性，还能够有效地解决溶解度低、生物利用率差等问题。因此，石莼寡糖的制备与活性研究成为海洋生物资源开发研究领域的热点。目前，石莼寡糖主要是通过化学法，物理法和酶法三种降解方式制备得到的。该研究对石莼多糖的化学组成、结构、提取、纯化和降解制备寡糖的方法进行了综述，并对石莼寡糖的生物活性研究进展进行了总结与展望，为石莼多糖及其寡糖的研究提供理论基础并以期为海洋藻类资源的高值化开发与有效利用提供参考。

Research Progress on the Structure, Preparation and Activity of Ulva Polysaccharides and Oligosaccharides

Ulva polysaccharide is the main component of the cell wall of Ulva marine green algae, and its complex structure and monosaccharide composition endow itself with various biological activities such as anti-virus, anti-inflammatory, anti-coagulation and antioxidant effects. However, the extracted Ulva polysaccharide has a highmolecular weight, low solubility and poor bioavailability, which greatly limits the high-value development and effective utilization of Ulva polysaccharide. Ulva oligosaccharide, a low-molecular-weight oligosaccharide obtained by degrading Ulva polysaccharide, can not only retain well various biological activities of Ulva polysaccharide, but also effectively solve the problems of low solubility and poor bioavailability. Therefore, the preparation and activity studies of Ulva oligosaccharides have become a hot spot in the field of marine biological resources development research. At present, Ulva oligosaccharides are mainly prepared by three degradation methods: chemical method, physicalmethod and enzymatic method. In this paper, the chemical composition, structure, extraction and purification of Ulva polysaccharide, and its degradation to prepare Ulva oligosaccharides, are reviewed. The research progress on the biological activities of Ulva oligosaccharides is summarized and prospected, which provides a theoretical basis for the research of Ulva polysaccharides and oligosaccharides, and a reference for high-value development and effective utilization of marine algae resources.