Structure elucidation and antioxidant effect of a polysaccharide from Lactarius camphoratum (Bull.) Fr.

In this study, a heteropolysaccharide was isolated from the fruiting bodies of Lactarius camphoratum (Bull.) Fr. through DEAE-cellulose column and Sephadex G-200 column. The L. camphoratum (Bull.) Fr. polysaccharide (LC-1) had a molecular weight of 9279 Da and was mainly composed of β-d-Glu and α-d-Gal which ratios were 2:1. Structural features of L. camphoratum (Bull.) Fr. polysaccharide (LC-1) were investigated by a combination of total hydrolysis, methylation analysis, gas chromatography-mass spectrometry (GC-MS), infrared (IR) spectra and nuclear magnetic resonance (NMR) spectroscopy. The results indicated that L. camphoratum (Bull.) Fr. polysaccharide (LC-1) had a backbone of (1 → 4)-β-d-glucopyranose residues which branches at O-6 based on the experimental results. The branches were mainly composed of one with →3)-α-d-galactopyranose residue. The antioxidant activity of LC-1 was evaluated with two biochemical methods, including 1,1-diphenyl-2-picrylhydrazyl (DPPH−) radical scavenging, scavenging activity of 2,2′-azino-bis(3-ethylbenzthiazoline-6-suphonic acid) diammonium (ABTS+) radical. The results indicated that LC-1 showed strong antioxidant.