一种礁膜多糖的化学组成和结构研究

polysaccharide MPS was extracted from Monostromaceae sp. with hot water, and further purified by a combination of Q Sepharose Fast Flow column and Sephacryl S-400/HR column. MPS was a homogeneous polysaccharide in size and charge, with an average molecular weight of about 58.4 kDa. Chemical composition analysis indicated that MPS contained 28.5% sulfate ester and 3.94% glucuronic acid. Monosaccharide composition analysis by GC demonstrated that MPS was mainly composed of rhamnose with minor amounts of xylose, glucose, mannose and galactose. On the basis of methylation and NMR spectroscopic analyses, the chain of the polysaccharide MPS was characterized to consist of →3)-α-Rhap-(1→, →2,3)-α-Rhap-(1→ and →2)-α-Rhap-(1→. Minor amounts of →2,3,4)-α-Rhap-(1→, →2,4)-α-Rhap-(1→, α-Rhap-(1→ and →3,4)-α-Rhap-(1→ were also detected. The sulfate groups were substituted at C-2 of the →3)-α-Rhap-(1→ and C-3 of the →2)-α-Rhap-(1→. The investigation demonstrated that MPS was a sulfated polysaccharide with different structural characteristics from other sulfated polysaccharides from seaweeds.