In this study, a novel heteropolysaccharide was isolated from the fruiting bodies of Boletus speciosus Forst through DEAE–cellulose column and Sephadex G-200 column. The Boletus speciosus Forst polysaccharide (BSFP-1) had a molecular weight of 13300 Da and was mainly composed of l-Man and d-Gal which ratios were 2:1. Structural features of Boletus speciosus Forst polysaccharide (BSFP-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 Boletus speciosus Forst polysaccharide (BSFP-1) had a backbone of (1→4)-α-l-mannopyranose residues which branches at O-6 based on the experimental results. The branches were mainly composed of one with →1)-α-d-galactopyranose residue. The antioxidant activity of BSFP-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 BSFP-1 showed strong antioxidant.

polysaccharide structure, antioxidant assay, Boletus speciosus Forst, Boletus speciosus Frost

• Compound ID: 18748
  

  a-D-Galp-(1-6)-+ | -4)-a-L-Manp-(1-4)-a-L-Manp-(1-

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  Structure type: structural motif or average structure ; 13300
  Compound class: O-polysaccharide, galactomannan
  Reference(s) to other database(s): GTC:G28786IS
  
   
  
  Boletus speciosus
  CSDB ID 43797 (all data & tools)