A novel polysaccharide (BEP) was extracted from Boletus edulis, and its structural characteristics and immunologic activity were evaluated. Our findings revealed that BEP (139 kDa) contained Man, Glc, and Gal in the molar ratio of 1:0.15:0.17 with typical characteristic absorption peaks of polysaccharides. Moreover, the results of methylation and 1D/²D NMR spectroscopy indicated that the backbone of BEP was →6)-α-Manp-(1→ and →3,6)-α-Manp-(1→, with the side chain →3)-β-Manp-(1→, →3)-α-Galp-(1→ and α-Glcp-(1→). The immunological activity tests demonstrated that the BEP could enhance phagocytosis of peritoneal macrophages and secrete NO and cytokines in a dose-dependent by activated macrophage. It was noteworthy that the secretions of NO, IL-6 and TNF-α at 400 μg/mL concentration were increased by 25.50%, 191.67% and 196.05% compared with the control group, respectively. The results illustrated that BEP was a novel polysaccharide, which may be marked as an immunologic agent in the food, pharmaceutical and cosmetic industries.

从牛肝菌中提取一种新型多糖（BEP），对其结构特征和免疫活性进行了评价。我们的研究结果表明，BEP (139 kDa) 含有摩尔比为 1:0.15:0.17 的 Man、Glc 和 Gal，具有典型的多糖特征吸收峰。此外，甲基化和一维/二维核磁共振谱的结果^表明，BEP的主链是→6)-α-Man p- (1→和→3,6)-α-Man p- (1→，与侧链 →3)-β-Man p -(1→, →3)-α-Gal p -(1→ 和 α-Glc p-（1→）。免疫活性测试表明，BEP可以增强腹腔巨噬细胞的吞噬作用，并通过活化的巨噬细胞以剂量依赖性方式分泌NO和细胞因子。值得注意的是，浓度为400 μg/mL的NO、IL-6和TNF-α的分泌较对照组分别增加了25.50%、191.67%和196.05%。结果表明，BEP是一种新型多糖，可在食品、医药和化妆品行业中被标记为免疫剂。