Okajima Maiko, Kaneko Tatsuo
Energy and Environmental Area, Graduate School of Advanced Science and Technology, Japan Advanced Institute of Science and Technology.
Yakugaku Zasshi. 2019;139(3):363-369. doi: 10.1248/yakushi.18-00177-2.
Polysaccharides (PS) are one form of biomass occurring in great abundance on earth and are promising organic material alternatives to petroleum-based ones. We have focused on PS produced by cyanobacteria. Aphanothece sacrum, which is a freshwater unicellular cyanobacterium, produces large amounts PS as a main component of the extracellular matrix. We successfully extracted the PS sacran from A. sacrum biomaterials and demonstrated that sacran contains carboxyls and sulfate groups. Furthermore, the constituent sugars of the sacran extracted were determined to be fucose, rhamnose, xylose, arabinose, mannose, glucose, galactose, glucuronic acid, galacturonic acid, and galactosamine. The sequence of sacran is still under investigation. In addition, we confirmed that the sacran was a supergiant with a high absolute molecular weight of 2.35×10 g/mol. Sacran shows a self-orienting behavior in dilute solution at a concentration range over 0.25 wt% to form a liquid crystalline structure. Using this property, it is possible to prepare a sacran cast film with an orientation structure, especially swelling in the thickness direction, to form anisotropic hydrogels. The anisotropy and degree of swelling of the hydrogels could be controlled by varying the heating temperature of the sacran cast file. Furthermore, sacran could be combined successfully with rayon as new fiber materials, and the sacran-rayon complex materials showed increased water absorption compared with the original rayon. This article introduces various applications of sacran in the industrial and medical fields.
多糖（PS）是地球上大量存在的一种生物质形式，是有望替代石油基材料的有机材料。我们专注于蓝藻产生的多糖。淡水单细胞蓝藻阿氏浮丝藻大量产生多糖作为细胞外基质的主要成分。我们成功地从阿氏浮丝藻生物材料中提取了多糖硫酸酯，并证明多糖硫酸酯含有羧基和硫酸基团。此外，所提取的多糖硫酸酯的组成糖被确定为岩藻糖、鼠李糖、木糖、阿拉伯糖、甘露糖、葡萄糖、半乳糖、葡萄糖醛酸、半乳糖醛酸和半乳糖胺。多糖硫酸酯的序列仍在研究中。此外，我们证实多糖硫酸酯是一种绝对分子量高达2.35×10 g/mol的超巨分子。多糖硫酸酯在浓度超过0.25 wt%的稀溶液中表现出自取向行为，形成液晶结构。利用这一特性，可以制备具有取向结构的多糖硫酸酯流延膜，特别是在厚度方向上膨胀，形成各向异性水凝胶。水凝胶的各向异性和膨胀程度可以通过改变多糖硫酸酯流延膜的加热温度来控制。此外，多糖硫酸酯可以成功地与粘胶纤维复合作为新型纤维材料，与原始粘胶纤维相比，多糖硫酸酯 -粘胶复合材料的吸水性增强。本文介绍了多糖硫酸酯在工业和医学领域的各种应用。
