Isolation,Purification And Structure Analysis Of Polysaccharides From Acanthopanax Senticosus

Acanthopanax senticosus is a kind of perennial herb. The root of Acanthopanax senticosus has been used as traditional medicine for thousands of years in China. The polysaccharides are major components in Acanthopanax senticosus roots. However, no report has been focused on their total fractionation and structure analysis so far. In order to have a better knowledge of the relationship between the chemical structure and properties of Acanthopanax senticosus polysaccharides, in this work, the isolation, purification and structure analysis of Acanthopanax senticosus polysaccharides(ASPS) have been studied.The water-soluble polysaccharides of Acanthopanax senticosus root were extracted with hot water, then precipitated by 75% ethanol. The yield of ASPS was 1.91%. ASPS contained 44.7% total sugar, 19.3% uronic acid and 5.6% protein. The monosaccharide composition of ASPS was Gal(24.2%), Glc(17.1%), Ara(15.4%), Rha(13.6%), Xyl(11.6%) and Gal A(14.9%).ASPS was separated into two fractions by DEAE-Cellulose chromatography: an unbound fraction ASPN eluted by water and a bound fraction ASPA eluted by 0.5 mol/L Na Cl. ASPN consisted of Gal(32.9%), Glc(25.7%) and Ara(22.6%). The distribution of ASPN’s molecular weight on Sepharose CL-6B was wide and heterogeneous.ASPA was further separated into 3 fractions by DEAE-Cellulose column: ASPA-N, ASPA-1 and ASPA-2, corresponding to 0, 0.3, 0.5 mol/L Na Cl elution, respectively. Since the yield of ASPA-N was very low, there was no further study of this fraction. Depending on the molecular weight distribution of the polysaccharide, the acidic fraction ASPA-1 was further separated by Sepharose CL-6B gel chromatography column, ASPA-1-A, ASPA-1-B were obtained.The major structural features of Acanthopanax senticosus polysaccharide fractions were elucidated using HPLC, FT-IR and 13 C NMR. The ASPN contained of glucan and Arabinogalactan. ASPA-1-A and ASPA-1-B both consisted of XGA and RG-I type pectin with Arabinogalactan as side chains. ASPA-2 consisted of RG-I pectin with Arabinogalactan-I as side chains.