Regioselective sulfation of β-glucan from Ganoderma lucidum and structure-anticoagulant activity relationship of sulfated derivatives.

In the present study, regioselective sulfation of β-glucan (GLP) from Ganoderma lucidum were firstly established by using 4,4'-dimethoxytrityl chloride and hexamethyldisilazane as protecting precursor. 2,4,6-O-sulfated, 6-O-sulfated and 2,4-O-sulfated GLP derivatives were prepared and the molecular weights (M) of derivatives were determined to range from 0.94 × 10 to 6.27 × 10 g/mol, while the degrees of sulfation (DS) were calculated to vary from 0.83 to 1.74. The regioselective sulfation of GLP was confirmed by FT-IR, C NMR spectroscopy and methylation analysis. Results indicated that the sulfated substitution sites were predominantly at C-6 in 6-O-sulfated GLP (SGLP) and C-4 in 2,4-O-sulfated GLP (SGLP), respectively. Clotting assays (APTT, PT and TT) in vitro showed that sulfate groups were essential for anticoagulant activity and SGLP exhibited much higher than others. Meanwhile, sulfated GLP with higher DS and M showed stronger anticoagulant activity in the case of the same condition.