Burana-osot Jankana, Hosoyama Saori, Nagamoto Yuzu, Suzuki Sho, Linhardt Robert J, Toida Toshihiko
Department of Pharmaceutical Chemistry, Silpakorn University, Nakornpathom, Thailand.
Carbohydr Res. 2009 Oct 12;344(15):2023-7. doi: 10.1016/j.carres.2009.06.027. Epub 2009 Jun 26.
A photochemical reaction has been developed for the partial de-polymerization of sodium alginate, a polysaccharide utilized in medicine, pharmacy, basic sciences and foods. An aqueous solution of sodium alginate was photochemically depolymerized to approximately 40% of its average molecular weight using ultraviolet light in the presence of titanium dioxide catalyst at pH 7 over a period of 3h. The products were separated giving four fractions all having an average molecular weight that was smaller than that of the starting material. Characterization of the guluronate (G) and mannuronate (M) contents, and determination of the M/G ratio of photochemically depolymerized alginate, were accomplished using (1)H NMR spectroscopy. The resulting M/G ratio was compared to that obtained for alginate fractions produced by acid hydrolysis. The M and G content, of each alginate fraction, was also assigned with regards to their occurrence in G-rich, M-rich or M/G heteropolymeric domains. This new depolymerization method might also be applicable in the preparation of alginate oligosaccharides for use in the food and pharmaceutical industries.
已开发出一种光化学反应，用于海藻酸钠的部分解聚，海藻酸钠是一种用于医学、制药、基础科学和食品领域的多糖。在pH值为7的条件下，在二氧化钛催化剂存在下，使用紫外光，将海藻酸钠水溶液在3小时内光化学解聚至其平均分子量的约40%。产物被分离成四个级分，所有级分的平均分子量均小于起始原料。使用核磁共振氢谱对光化学解聚海藻酸盐的古洛糖醛酸（G）和甘露糖醛酸（M）含量进行表征，并测定M/G比。将所得的M/G比与酸水解产生的海藻酸盐级分的M/G比进行比较。还根据每个海藻酸盐级分在富含G、富含M或M/G杂聚结构域中的出现情况，确定了其M和G含量。这种新的解聚方法也可能适用于制备用于食品和制药行业的海藻酸寡糖。
