Further analysis of the structure and immunological activity of an RG-I type pectin from Panax ginseng

► The ginseng pectic fraction WGPA-2-RG was identified to have RG-I structure. ► WGPA-2-RG has a small backbone and long AG-II side chains. ► Most of the Gal are close to molecular core and all Ara on molecule surface. ► Ara residues are important to lymphocyte proliferation and NO production.