白玉菇抗肿瘤活性多糖 WHB3 的结构表征

文章采用热水浸提及 DEAE-Cellulose 离子交换层析从白玉菇 (White Hypsizygus marmoreus) 子实体中分离纯化出均一多糖组分 WHB3。糖醛酸测定表明 WHB3 不含糖醛酸；单糖组成分析表明 WHB3 由葡萄糖组成；相对分子质量测定结果为 $ 2.3 \times 10^{5} $ Da；结构分析结果表明，WHB3 主链由 $ (1 \rightarrow 6) $- $ \beta $-D-Glcp 组成，其中部分 $ (1 \rightarrow 6) $- $ \beta $-D-Glcp 的 O-3 位连有支链 1- $ \alpha $-D-Glcp。通过体外肝癌细胞 HepG2 抗肿瘤实验模型考察白玉菇多糖 WHB3 及其部分酸水解产物 WHB3-S 的抗肿瘤活性，结果表明 WHB3 和 WHB3-S 对肝癌细胞 HepG2 的增殖具有显著的抑制作用，且与多糖质量浓度呈正相关，多糖质量浓度达到 $ 500 \mu g/mL $ 时，抑制率分别达到 38.18%、35.88%。构效关系分析表明，与 WHB3 相比，WHB3-S 在各质量浓度下的抑制率明显较低，说明相对分子质量的减小及支链的缺失对 WHB3 的抗肿瘤活性有显著的影响，降低了 WHB3 的肿瘤抑制活性。研究结果为揭示白玉菇多糖化学结构与生物活性之间的潜在联系提供更多依据。

In this paper, the crude polysaccharide was isolated from the fruiting bodies of white Hyp-sizygus marmoreus by water extraction at boiling temperature. After purification by DEAE-Cellulose ion exchange chromatography, the homogenous polysaccharide fraction WHB3 was obtained. The results of uronic acid determination showed that WHB3 contained no uronic acid. Monosaccharide composition analysis showed that WHB3 contained only glucose and its relative molecular mass was determined to be $ 2.3 \times 10^{6} $ Da. Structural characterization results indicated that the main chain of WHB3 was consisted of $ (1 \rightarrow 6) $- $ \beta $-D-Glcp, part of which was connected with branched 1- $ \alpha $-D-Glcp at the O-3 position. The anti-tumor activity of WHB3 and its hydrolysate WHB3-S on HepG2 cells was investigated in vitro by establishing hepatocellular carcinoma cell model. The results showed that the inhibitory effects of WHB3 and WHB3-S on HepG2 cells were positively correlated with the polysaccharide mass concentration. The structure-activity relationship analysis showed that the inhibitory rates of WHB3 and WHB3-S on HepG2 cells were 38.18% and 35.88% when the polysaccharide mass concentration was 100 mg/g.