Purification And Structural Analysis Of Polysaccharides From Russula Virescens

Russula virescens,also known as qing tou jun,belong to Fungi,Basidiomycetes,Agaricomycetes,Russulales,Russulaceae.It is a kind of large edible fungus,the epidermis often cracks into the small plaque of polygon,the fungus flesh white,the quality thick has the high edible value.Polysaccharides are important structural units and active components of edible mushrooms,exhibited multiple bio-activities including anti-tumor,immunomodulatory,anti-inflammatory,hypoglycemic and anti-oxidant activities.At present,the research on the polysaccharides of Russula virescens is mainly focused on the extraction and bioactivity of polysaccharides.However,a few reports have been found on the systematic classification and structural analysis of the polysaccharides.In order to understand the composition and structure of different kinds of polysaccharides in Russula virescens,we designed the research contents of this subject:The dried Russula virescens are used as experimental materials.Using boiling water extraction and alcohol precipitation,The total polysaccharide was obtained,and the yield was 5.62%(the total sugar content was 66%,the protein content was 3.4%,the ash content was 8.8%,almost no uronic acid or starch was found.The monosaccharide composition analysis showed that the crude polysaccharide was mainly composed of Glc(85.5%)and Gal(7.4%),In addition,it also contains Man(3.6%)and Fuc(0.9%),and a small amount of Ara(0.8%)and GlcA(0.6%).DEAE-Cellulose ion exchange chromatography is used to classify the charges of WRVP,The neutral fraction(WRVP-N)are obtained by distilled water elution and the acidic fraction(WRVP-A)eluted by 0.25 M NaCl.Further purification was carried out by using Sepharosecl-6B and column chromatography to obtain final homogeneous fractions WRVP-N-b?WRVP-N-c and WRVP-A-a.Molecular weight determination,monosaccharide composition analysis,methylation analysis and NMR analysis showed that WRVP-N-b and WRVP-N-c have same structure.they were mainly composed of Gal and Man and Fuc and Glc.The molecular weight of WRVP-N-b was 11 kDa and the molecular weight of WRVP-N-c was 4.4 kDa.The structure of WRVP-N-b was ?-1,6-Galp and ?-1,6-D-Me-Galp.the non-reducing ends Manp and Galp and Fucp of the ?-structure and Fucp of the ?-structure are connected to the C-2 position of the Galp,and it is Fucomannogalactans.WRVP-A-a was mainly composed of Glc(89.7%),and its molecular weight was 430 kDa,which is the structure of ?-1,6-D-Glcp,the non-reducing ends Glcp of the ?-structure,?-1,3-D-Glcp and t-?-D-Glcp are connected to the C-3 position of the Glcp,the structure is Glucans.