Abstract: Two neutral polysaccharides (GDPs-1 and GDPs-2) and one acidic polysaccharide (GDPs-3) were separated and purified from water-soluble crude polysaccharide from the leaves of Gynura davaricata (L.) DC. by D315 resin column and subsequent Sephadex G-25 gel column chromatography. GPC analysis showed that the average molecular weights of GDPs-1, GDPs-2 and GDPs-3 were 1.06 × 104, 4.17 × 103 D, and 3.74 × 103 D with a purity of 94.08%, 92.3% and 99.8%, respectively. Infrared spectra preliminarily confirmed that the purified fractions were polysaccharides. GDPs-1 was characterized as α- and β-configuration, and GDPs-2 and GDPs-3 asα-configuration. Nuclear magnetic resonance (1H-NMR) results further proved that the polysaccharides contained only α-configuration. In conclusion, all these investigations can provide reference data for further studies on structural characterization and bioactivity of Gynura davaricata polysaccharides.

Key words: Gynura davaricata (L.) DC., polysaccharide, separation and purification, infrared spectrum, configuration, nuclear magnetic resonance