采用氯磺酸-吡啶法对米糠多糖(RBPS2 a)进行硫酸酯化修饰得到硫酸酯化米糠多糖(SRBPS2 a),使用HPGPC测定SRBPS2 a的分子质量,利用红外光谱和13CNMR进行结构分析,应用体内、外抗肿瘤试验对SRBPS2 a抗肿瘤活性进行评价。结果发现:SRBPS2 a的取代度为1.29,分子质量为3.5×105u,在体内和体外对小鼠乳腺癌细胞EMT-6有显著的抑制作用。RBPS2 a经硫酸酯化修饰后,SRBPS2 a主链结构保持-β(1→3)-D-甘露糖不变,侧链被切除,硫酸基团的取代发生在C-2和C-4位上,C-6氧化形成糖醛酸甲酯。

A novel sulfated polysaccharide SRBPS2a with anti-tumor activity was derived from defatted rice bran by chlorosulfonic acid-pyridine(CSA-Pyr) method.The average molecular weight of SRBPS2a was 3.5×105 u and the degree of sulfation(DS) was 1.29.The Fourier-Transform Infrared Spectra(FT-IR) and 13C NMR spectroscopy analysis revealed that SRBPS2a was mainly consist of β-(1→3)-D-galactopyranosyl residues,the sulfate substitution site was on C-2 and C-4 while the side chains were cut off during the sulfated reaction.Furthermore,SRBPS2a exhibited evident growth inhibition on mouse mammary tumor EMT-6 cells both in vitro and in vivo.