Structure feature and antitumor activity of a novel polysaccharide isolated from Lactarius deliciosus Gray

A novel heteropolysaccharide was isolated from the fruiting bodies of Lactarius deliciosus Gray through DEAE-cellulose column and Sephadex G-100 column. The L deliciosus Gray polysaccharide (LDG-A) had a molecular weight of 1.1 x 10(4) Da and was mainly composed of L-mannose and D-xylose (L-Man and D-Xyl) which ratio was 3:1. As a precondition to understand the bioactivity, structural feature of L. deliciosus Gray polysaccharide (LDG-A) were investigated by a combination of total hydrolysis, methylation analysis, gas chromatography-mass spectrometry (GC-MS), scanning electron microscope (SEM), infrared (IR) spectra, nuclear magnetic resonance (NMR) spectroscopy and dynamical analysis of the atomic force microscope (AFM) studies. The results indicated that L deliciosus Gray polysaccharide (LDG-A) had a backbone of 1,6-disubstituted-alpha-L-mannopyranose which branched at O-2 and the branches were mainly composed of a -> 3)-alpha-D-xylopyranose residue. LOG-A exhibited significant anti-tumor activates in vivo. L. deliciosus Gray may be one ideal sources of antitumor development. (C) 2012 Elsevier Ltd. All rights reserved.