A hyperbranched β-D-glucan with compact coil conformation from Lignosus rhinocerotis sclerotia

Its structural characteristics were determined by GC–MS, FT-IR, GC, 1D and 2D NMR combined with Smith degradation and methylation analysis. The LRP had a (1 → 3)-β-D-Glcp backbone with every three residues bearing a (1 → 6)-linked and hyperbranched side chain that contained three (1 → 6)-β-D-Glcp residues as secondary main chain and two terminal β-D-Glcp residues linked at O3. The degree of branching was 0.76 from GC–MS analysis, implying a highly branched structure for LRP. The Mw, <S2>z1/2, Rhand [η] values of LRP in 0.25 M LiCl/DMSO were measured by SEC-MALLS-Vis-RI combination technology to be 2.88 × 105 g/mol, 30.36 nm, 22.34 nm and 131.50 ml/g, respectively. Furthermore, the exponent α of [η]–Mw, β of <S2>z1/2–Mw, the fractal dimension dfand molecular parameter ρ were determined to be 0.20, 0.33, 2.50 and 1.36, demonstrating that the LRP was a hyperbranched polysaccharide and adopted a compact coil conformation in LiCl/DMSO.