Isolation,Purification,Structure Identification And Hypoglycemic Activity Of Polysaccharides From Achyranthes Bidentata,Mori Fructus And Polygonatum Odoratum

In this paper,to study the polysaccharids from three kinds of traditional Chinese medicine Achyranthes bidentata,Mori fructus and Polygonatum odoratum.Eight homogeneous polysaccharids were obtained through extraction,separation and purification.The primary structures and advanced structures were identification by chemical and spectral methods.Fristly,the crude polysaccharides(ABPB,MF70,MF90 and POB)were obtained by water extract-alcohol precipitation or alkali extract-alcohol precipitation from A.bidentata,M.fructus and P.odoratum.Eight polysaccharides(denoted ABPB-4,MFP70-1-1,MFP70-2-1,MFP90-1-1,MFP90-1-2,POB-2-1,POB-2-2 and POB-2-3)were isolated and purified from ABPB,MF70,MF90 and POB via ion exchange chromatography(DEAE-52)and size-exclusion chromatography(G-75).Then,the homogeneity was determined through HPGPC and specific rotation method.The results showed that they were all homogeneous polysaccharides with molecular weight of 63.5k Da,4.1 k Da,4.2 k Da,9.2 k Da,2.4 k Da,42.1 k Da,9.2 k Da and 10.3 k Da,respectively.Infrared spectrum(IR)analysis,monosaccharide composition analysis,gas chromatography-mass spectrometry(GC-MS)after total acid hydrolysis analysis and nuclear magnetic resonance(NMR)detection were carried out to characterize the primary structure of eight homogenous polysaccharides.Congo red experiment and SEM analysis showed that there was no triple helix structure in the eight refined polysaccharides,and they showed different morphology under scanning electron microscope(SEM),which may be related to different molecular weight,monosaccharide composition and connection mode.In this paper,the structures of eight homogenous polysaccharides have not been reported.Pharmacological studies had shown that both crude polysaccharides and homogenous polysaccharides of M.fructus had certain inhibitory effects on the activities of α-glucosidase and α-amylase.Among them,MFP70-1-1 had the best activity and potential medicinal value is worthy of further exploration and research.