Study On The Distribution And Existing Forms Of Zinc In Crassostrea Hongkongensis And The Structure Of Zinc Polysaccharides

Zinc is an important trace component of the human body and plays an important role in many physiological activities.The human body cannot store and synthesize zinc,so it needs to be supplemented by food.Simple food intake cannot meet the needs of the human body.The existence of zinc affects the digestion and absorption of zinc.The bioavailability and safety of organic zinc are higher than that of inorganic zinc,and the bioavailability and safety of natural organic zinc are also significantly due to the artificially chelated organic zinc.Oysters are rich in zinc,and many of its biological activities are closely related to the presence of zinc.Proteins and polysaccharides combine with zinc to give them special biological activities.Biological activities are also closely related to their own molecular weight and spatial structure.This study took Crassostrea hongkongensis as the research object,explored the distribution rules and existing forms of zinc in oysters,selected the polysaccharide component with high zinc content to separate and purify,and conducted structural studies on the purified components.It provides basic data for the development and utilization of zinc in oysters and the study of the activity of zinc polysaccharides,and provides an important reference for the future application and development of oysters.The research contents were as follows:1.ICP-MS technology was used to detect the content of zinc in whole organs,gills,mantle membrane,adductor muscle,visceral mass and oyster extracts,and preliminary analysis of its presence in the whole organs.The zinc concentration in the whole organs of oyster was 1267.51±2.85 ?g/g(dry basis,the same below),and the gill zinc concentration in tissues and organs was the highest,reaching 2242.63±22.10 ?g/g;The zinc content in the visceral mass accounts for 45.46% of the maximum proportion of the oyster's whole organs;The ratio of inorganic to organic zinc in the whole organs of oysters was about1.55:1;The zinc concentrations of the protein and polysaccharide components in the extract were 155.07±3.30 ?g/g and 1137.52±19.78 ?g/g,respectively.The organic zinc element in the extract was mainly present in the polysaccharide component;The zinc concentrations of the protein and polysaccharide components in the residue were766.15±18.25 ?g/g and 253.50±4.00 ?g/g,respectively.The organic zinc element in the residue was mainly present in the protein component.2.The zinc polysaccharide was extracted by the water bath extraction method,and the zinc polysaccharide was separated and purified by DEAE52 ion exchange chromatography,and the purity of the zinc polysaccharide was identified by ultraviolet spectroscopy.The results showed that the concentration of zinc in the polysaccharide fraction extracted in a60? water bath was the highest.The polysaccharide fraction extracted in a 60? water bath was selected for separation and purification,and the two fractions CT1 and CT2 were eluted with ultrapure water and 0.1 mol/L Na Cl solution,respectively.The recovery rates of CT1 and CT2 were 46.13% and 21.07%,respectively.The zinc concentrations of CT1 and CT2 were 922.18 ?g/g and 62.56 ?g/g,respectively.Through UV spectrum analysis,it was found that there were almost no proteins and nucleic acids in CT1 and CT2 components,and there were characteristic absorption peaks of polysaccharides near200 nm.3.The solubility and denaturation temperature of CT1 components were studied by using a pH meter and a synchronous thermal analyzer.The content of sulfuric acid and uronic acid was studied by the Ba Cl-gelatin and m-hydroxybiphenyl method.The characterization of the spatial conformation of zinc and polysaccharides was studied by scanning electron microscopy combined with energy dispersive spectroscopy,X-ray diffraction,and Congo red experiments,and the precise structural characterization of zinc polysaccharides was studied by nuclear magnetic resonance,infrared spectroscopy,ion chromatography,and high performance liquid phase.The results showed that the content of sulfate group and uronic acid in CT1 component were 0.1% and 0.97%,respectively.The solubility of zinc in zinc polysaccharide was the highest when the pH was 4,and the denaturation temperature was 207.1?.The monosaccharides of the CT1 component were glucose,mannose,and ribose.The percentages of each monosaccharide were glucose99.8%,mannose 0.13%,and ribose 0.08%,and their relative molecular weights ranged from 4k Da to 2044 k Da.The CT1 component had an amorphous structure and a stable triple helix structure.Scanning electron microscopy revealed that there were mainly irregular flake and granular substances in the component.The presence of zinc in the CT1 component did not change the surface morphology and amorphous structure of the polysaccharide,and changes the triple helix structure.CT1 did not have the characteristic absorption peak of zinc oxide,and the absorption peaks of OH and COOH groups and uronic acid may be the binding sites of zinc and polysaccharides.The CT1 component had ?-type and ?-type pyranose,without furanose and C-6 acetamido,C6 and sulfate were not substituted,the hydroxyl substitution of C4 may be related to zinc.