The Extraction,Purification,Structural Analysis And Bioactivity Research Of Polysaccharide From Rubus Suavissimus S.Lee

The research of polysaccharide is the frontier field of life science research,especially the plant polysaccharide.It has many biological activities,such as regulating immunity,inhibiting tumor growth,reducing fatigue,lowering blood sugar.Rubus suavissimus(Rosaceae,Rubus plants),it has many flavonoids,tea polyphenols,glycosides and polysaccharide,it also known as sweet tea and teamainly produced in Guangxi province,it has a long history in the civil application useing for preventing and curing diseases.In this study,the structure and biological activity of glycosides were studied.The crude polysaccharides were extracted from the leaves of Rubus suavissimu by hot water and alkali solvent.The crude polysaccharides were isolated and purified by DEAE-52 column chromatography,and a total of eight kinds of polysaccharides were obtained.Using the method of m-hydroxydiphenyl,phenol sulfuric acid method and Coomassie brilliant blue method were masured content of uronic acid,neutral sugar and protein.The average molecular weight and the monosaccharide composition were determined by GPC,GC.The main structure of their information were researched by IR,NMR,periodate oxidation and methylation reactions.The main conclusions are as follows:Structural analysis showed that:(1)The contents of neutral sugar,protein and average molecular weight of Polysaccharides from Rubus were different by reason of different extraction method.(2)Alkaliextracted polysaccharide's molecular weight greater than the water extraction one.(3)All polysaccharides were mainly composed of rhamnose,ribose,Arabia sugar,mannose,glucose and galactose,even the amount is diffent.(4)The UV spectra showed that eight components contained O-glycosidic bond.(5)The IR spectra showed that eight components,most of them were beta configurations.(6)Based on the data of experiences,the backbone repeat structure of WRSL is [1?)-?-D-Glu-(4?] and ARSL is [1?)-?-D-Gal-(4?].(7)The Congo red experiment showed that there were no three helical structures in the structure of eight polysaccharides from Rubus.Biological activity research showed that:(1)The Polysaccharides extracted from hot water and alkali had antioxidant activity in vitro during scavenging DPPH and ABTS free radical.And the antioxidant activity of aqueous extractive polysaccharide components better than that of the polysaccharides obtained by alkali extraction.(2)The Polysaccharides extracted from hot water and alkali had an anticoagulation in vitro,especially in the extension of APTT.That means,WRSL and ARSL plays a role in anticoagulation mainly through the endogenous coagulation system.(3)The activity of polysaccharide containing(1?4)linked glycosidic bond was better than that of(1?6)linked glycosidic bond,both in antioxidant or anticoagulant experiments in vitro.