A novel Stauntonia leucantha fruits arabinogalactan: isolation and structural characterization

Polysaccharides were the key ingredients of many herbal medicines, and were responsible for multiple pharmacological activities. In this study, a novel polysaccharide fraction, named SLP-2, was isolated from Stauntonia leucantha fruits, and purified by DEAE-52 and Sephadex G-100 column chromatography . Furthermore, SLP-2 was identified by congo red, methylation , partial acid hydrolysis and NMR . The results indicated that the backbone of SLP-2 was composed of →4)-β-D-Gal p -(1 → 4)-β-D-Gal p -(1→ substituted at C-6 with 1,5-linked arabinan . SLP-2 had good anti-oxidation ability in vitro. Surprisingly, we found that reduction of carboxyl groups and methylation of hydroxyl groups enhanced the ability to scavenge 2,2′-azinobis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS) radicals and inhibit lipid peroxidation , and weakened the activity to scavenge 1,1-diphenyl-2-picrylhydrazyl (DPPH) radicals and reduce ferric iron.