| A heteropolysaccharide,HPS3aS,and an arabinogalactan-protein,HPS3d,were isolated from Hedysarum polybotrys Hand.-Mazz using anion-’exchange on DEAE-52 cellulose and gel-permeation chromatography on sephadex G-200.Elemental analysis indicated that HPS3aS and HPS3d contained small amount of sulfate groups(4.73%,5.57%in mass).HPS3d consisted of 3.40%protein and 13.30%uronic acid.The molecular weight of HPS3aS and HPS3d were measured to be 1.22 × 104 Da,8.46 × 104 Da by size exclusion chromatography-multi angle laser light scattering(SEC-MALLS),respectively.HPS3aS took globular shape conformation in 0.1MNaNO3,but HPS3d was highly branched structure.Sugar analysis showed that HPS3aS was composed of glucose and galactose,HPS3d consisted of rhamnose,arabinose,glucose,galactose and galacturonic acid.By a combination of instrumental and chemical analysis,including partial acid hydrolysis,methylation analysis,gas chromatography-mass spectrometry(GC-MS),Fourier transform(FT-IR)infrared spectra,nuclear magnetic resonance(NMR)spectroscopy,the results revealed that HPS3aS had a backbone of α-D-(1→4)-linked glucopyranose residues,which occasionally branched at O-6.The branches were composed of(1→4)-linked galactopyranose residues and terminated with glucopyranose residues.The Sulfate groups attached to the branches at O-6 position of galactosyl residues.The backbone of HPS3d mainly consisted of(1→4)-linked galactopyranose and(1→4)-linked galacturonopyranose,and that the side chains were composed of(1→)-linked glucopyranose,(1→2)-linked rhamnopyranose,(1→3,5)-linked arabinofuranose,(1→5)-linked arabinofuranose and(1→)-linked arabinofuranose.The sulfate groups might also attach to the C-6 position of galactose.Nineteen amino acids were detected,cystine,glutamic acid and hydroxyproline being the major ones.The existence of O-glycosidic linkage in HPS3d was demonstrated with a β-elimination reaction.The anti-tumor effects of four components in Radix Hedysari polysaccharide 3 were investigated by MTT)assay.The results suggested that four fractions from HPS3 had anti-tumor activities on the human stomach cancer MKN45 cells.HPS3b had more obviously inhibitory activity on the growth of tumor cells in vitro than the other fractions with the same dose and could significantly inhibit cell growth in a dose-dependent manner.lt was indicated that HPS3 could have developed a possible anti-cancer drug. |
