A new solvent of cellulose (1.5 mol/L NaOH/0.5 mol/L urea aqueous solution) was used as one of the homogeneous reaction media of polysaccharides for methylation

hydroxyethylation and hydroxypropylation. A water insoluble β-(1→3)-D-glucan

sample PCS3-Ⅱisolated from fresh sclerotium of Poria cocos was sulfated in dimethyl sulfoxide (Me2SO)

carboxymethylated in NaOH

isopropanol solution

as well as methylated

hydroxyethylated and hydroxypropylated in the new solvent system

respectively

to obtain five water-soluble derivatives coded as S-PCS3-ⅡC-PCS3-Ⅱ

M-PCS3-Ⅱ

HE-PCS3-Ⅱand HP-PCS3-Ⅱ.Their chemical structure and distribution of substitution were characterized by infrared spectroscopy (IR)

elementary analysis (EA)

1H-NMR

13C-NMR

2D-COSY

2D-TOCSY and 2D-1H-detected 1H13C HMQC spectra. The results reveal that the relative reactivity of hydroxyl groups of the β -(1→3)-D-glucan is in the order C-6 > C-4 > C-2 on the whole. The substitution of the samples S-PCS3-Ⅱ

C-PCS3-Ⅱ and M-PCS3-Ⅱoccurred mainly at C-6 position and secondly at C-4 and C-2 positions

and that of HE-PCS3- Ⅱoccurred at C-6 and C-4 positions and of HP-PCS3-Ⅱalmost completely occurred at C-6 position. The degrees of substitution (DS) obtained from 13 C-NMR range from 0.23 to 1.27. The water solubility of the derivatives is in the order S-PCS3-Ⅱ>C-PCS3-Ⅱ>M-PCS3-Ⅱ>HE-PCS3-Ⅱ>HP-PCS3-Ⅱ. This work provides a novel and nonpolluting process for the methylation

hydroxyethylation and hydroxypropylation of β-(1→3)-D-glucan.