Isolation, purification and structural characterization of polysaccharide POP I b from portulace oleracea L

In order to study the composition and structural characterization of poly saccharide POP I b from portulace oleracea L., the polysaccharides were extracted by boiling water and precipitated by 95% ethanol firstly. After being removed protein by Sevage reagent, the refined POP I b was isolated and purified by DEAE-cellulose column and Sephadex G-200 column. Its homogeneity was proved by cellulose acetate film electrophoresis and Sephadex G-200 column. And its compositions and structures were measured and analyzed preliminarily by thin layer chromatography (TLC), GC, IR and NMR. The results showed that POP I b is homogeneous and it is made up of arabinose, galactose and galacturonic acid. The mole ratio of arabinose and galactose is 1:1.72, meanwhile, there are characteristic absorption bands of polysaccharide and β-(1→4) glycoside linkages in its structure. POP l b is considered as a kind of heteropolysaccharide with complex structure containing much arabinose, galactose and galacturonic acid, and is obtained for the first time from portulace oleracea L.