| Mytilus edulis Linnaeus are resouceful marine mollusk, widely distributed on the coast of Liaoning, Shandong, Zhejiang and other provinces. Mytilus edulis Linnaeus are rich in delicious meat, nutritional value, known as"sea eggs". And the Mytilus edulis Linnaeus polysaccharides have many bioactivities, such as anticoagulant, anti-tumor, immune function. In this paper, the crude polysaccharides were extracted by different methods from Mytilus edulis Linnaeus which were from seas of hu-Island in Qingdao and physicochemical properties were analyzed more systematically. Many components with high purity were obtained by two-step purification of Gel permeation and anion exchange chromatography. The structure of polysaccharide (HWS) extracted with water at 60℃(HW) was confirmed and the primary structure of polysaccharide (MT0-A1) extracted with enzymolysis(MT) was elucidated by chemical and modern analytical techniques.The crude polysaccharides were extracted respectively by cold distilled water,water at 60℃and combined with enzymolysis (papain and trypsin) and. Physicochemical properties of the crude polysaccharides extracted with cold distilled water(LT), MT and HW were determined. The monosaccharide compositions of the crude polysaccharides with LT and HW which were analyzed by precolumn derivatization high performance liquid chromatography were simple, including mostly Glc. While the component of MT had complex monosaccharide composition, and mostly including Man, GlcN, GalN, Gal and Fuc.The crude polysaccharides of LT and MT were further purified by Q sepharose 4 Fast Flow, Sephacryl S300 and SephadexTM G-25 Fine, and many kinds of polysaccharides (named LTS1-A1, LTS1-B, LTS2-B1, LTS2-B2, MT0-A1 and MT1-B1)with high purity were acquired. All the components showed a single peak on high performance gel permeation chromatography. Relative molecular mass of these components were 31.8, 40.7, 48.1, 47.4, 3.9 and 4.8 kD, respectively. The monosaccharide compositions of LTS1-A1 was simple, including mostly Glc, while LTS1-B including mostly Man, GlcN, GalN, Glc, Gal and Fuc. The monosaccharide compositions of LTS2-B1, LTS2-B2, MT0-A1 and MT1-B1 were similar, including mostly Man, GlcN, GalN, Gal and Fuc.HW was purified by Sepharcryl S300, and the component with high purity (named HWS) was acquired. The contents of total sugar and protein were 98.5% and 1.1%, respectively. The relative molecular mass of HWS is 574.5 kD. Based on the research of its physicochemical properties, the structure of HWS was further studied by methylation and GC/MS analysis, periodate oxidation and smith degradation, FT-IR and 2D NMR spectroscopy. Our data showed that HWS was a glucan with a (1→4)-linkedα-D-Glcp backbone, with a little (1→2,4)-linked-α-D-Glcp and→6)-β-Glc-(1→in side chains. There was about one branch in 6 backbone residues on average.The structure of MT0-A1 was elucidated by methylation and GC/MS analysis, FT-IR and 2D NMR spectroscopy. It was showed that there were kinds of structural unit, including→3)-β-D-GlcNAcp-(1→;α-L-Fucp-(1→and→3)-α-L-Fucp;→2)-α- D-Galp-(1→;→3)-α-D-Manp-(1→and→4)-α-D- GalNAcp-(1→. These data provided base for the further research about bioactivities of the polysaccharide from Mytilus edulis Linnaeus.There are seldom reports about the systematic research of the physicochemical properties, purification and structure of Mytilus edulis Linnaeus polysaccharides, though the preliminary research of physicochemical properties and biological activity about Mytilus edulis Linnaeus polysaccharides had been reported. In this paper, the physicochemical properties of seven polysaccharide fractions with high purity were analyzed. The systematic strutural research of HWS and MT0-A1 provided foundation for the further research about structure-activity relationship of polysaccharides from Mytilus edulis Linnaeus. |
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