Structural analysis of ginseng polysaccharides extracted by EDTA solution

In the present study, polysaccharides were extracted from ginseng with ethylene diamine tetraacetic acid (EDTA) after consecutive hot water and alpha-amylase extraction. The yield of EDTA-soluble ginseng polysaccharide (EGP) was 6.0%. Using anion exchange and gel permeation chromatography, EGP was fractionated into one major starch-like glucan (EGP-N), two minor glucan fractions (EGP-1a and EGP-1b) and four pectic fractions (EGP-2a, EGP-2b, EGP-3a and EGP-3b). High-performance liquid chromatography, fourier transform-infrared and nuclear magnetic resonance analyses demonstrated that the four pectic fractions were composed of both homogalacturonan and type-I rhamnogalacturonan domains. EGP had a better stimulation effect on lymphocyte proliferation in vivo than hot water and alpha-amylase extracted polysaccharides, demonstrating that some novel and active polysaccharides can be extracted from ginseng by EDTA. These results provide new insight into the preparation of ginseng polysaccharides that may have potential use in the food and pharmaceutical industries.