银耳孢糖的化学结构初步研究及其免疫活性

Structure and Biological Activity of Tremella fuciformis Polysaccharide

目的:从银耳孢糖中分离、纯化3种均一多糖,TSP2a～TSP2c,研究其结构特征及生物活性。方法:银耳孢糖经DEAESephadexA50分离得TSP2,进一步采用SephadexG150分离纯化得TSP2a～2c,经凝胶色谱法和HPGPC方法鉴定其纯度。利用化学方法和色谱及光谱分析方法进行结构研究。采用放射免疫法测定了TSP2、TSP2a～TSP2c刺激人外周血单核细胞(PBMC)后促进细胞因子IL1α、IL6、IL8分泌的增加。结果:TSP2a～TSP2c为均一多糖,分子量分别为1100kD、500kD、400kD。组成糖为岩藻糖(Fuc)、木糖(Xyl)、甘露糖(Man)、葡萄糖(Glc)和葡萄糖醛酸(GlcA)。其结构都以(1→3)DMan为主链,并在O2,O4,O6位上有分支点。各均一多糖在不同程度上对细胞因子的产生起到促进作用。结论:TSP2a～TSP2c均为一多分枝的结构复杂的酸性杂多糖,具有显著的免疫活性。

AIM： To investigate polysaccharide from Tremella fuciformis Berk（TSP）, and the structural characteristics and biological activities. METHODS：TSP-2 was obtained by DEAE-SephadexA-50 gel columns chromatography from crude polysaccharide. TSP-2 was purifited to obtain TSP-2a-TSP-2c by Sephadex G-150 column chromatography and the purity was identifited by gel chromatography and HPGPC. Both chemical and spectral analyses were used to investigate the structural characteristics, Cytokine-stimulating effect on PBMC was studied by the method of radioimmunoassav. RESULTS： TSP-2a - TSP-2c were uniform singal peek and molecular weight were 1100 kD, 500 kD, 400 kD, respectively. They were composed of Fuc, Xyl, Man, Glc and GlcA. Glycosidic linkage analysis showed that they all had （1→3）-D-Man backbones, with the branching points at the 2-, 4-, or 6- position. They had similar cytokine stimulating activity. CONCLUSION： The results suggest that TSP-2a-TSP-2c were a highly branched heteroglycan with observable immune activity.