Advances in the preparation of alginate oligosaccharides and its biological functions / 生物工程学报

Alginate is a group of polyuronic saccharides that are widely used in pharmaceutical and food industry due to its unique physicochemical properties and beneficial health effects. However, the low water solubility and high viscosity of alginate hampered its application. Alginate oligosaccharide (AOS) is a decomposition product of alginate and has received increasing attention due to its low molecular weight, high water solubility, safety, and non-toxicity. The wide-ranging biological functions of AOS are closely related to its structural diversity. AOS with distinct structures and biological functions can be obtained by different methods of preparation. This review summarized the biological functions of AOS reported to date, including anti-tumor, immunomodulatory, anti-inflammatory, antioxidant, prebiotic, and anti-diabetes. The preparation of AOS, as well as the relationship between the structure and biological functions of AOS were discussed, with the aim to provide a reference for further development and application of AOS.

A method for preparation of saturated oligosaccharides from alginate / 中国海洋药物

Objective To report a method for preparation of saturated oligosaccharides from al- ginate. Methods The alginate was degraded by acid hydrolysis, followed by fractionation at pH 2.85 resulting in the homopolyguluronic acids (PG) and homopolymannuronic acids (PM). The alginate-derived homopolymers were further degraded by acid hydrolysis at pH 3.8, 120 ℃ for 3 h, and at pH 4, 120 ℃ for 4 h, respectively. The resulted acidic hydrolysates were separated by gel permeation chromatography to get oligosaccharide fractions, and the oligosaccharides were obtaind by repeated purification on gel chromatography. The structures of the oligosaccharides were characterized by analyses of infra-red spectroscopy (IR), nuclear magnetic resonance spectrometry (NMR), and mass spectrometry (MS). Results It was showed that the derived oligosaccharides were in saturated structures with the same structure characteristics as the original alginate macromolecule. Conclusion The method des cribed in this paper is a effective and convenient approach for the preparation of low-molecular-weight oligosaccharides from alginate.