条斑紫菜多糖的纯化、理化性质及其免疫活性研究

Purification, Physicochemical Properties and Immunomodulatory Activity of Polysaccharides from Porphyra yezoensis

利用DEAE纤维素-52和Sephadex G-100凝胶柱层析对木瓜蛋白酶法提取的条斑紫菜多糖进行分离纯化，得到PPYP-1、PYP-2、PYP-3和PYP-4多糖组分。然后对PYP-2、PYP-3和PYP-4单一组分的总糖含量、糖醛酸含量、硫酸基含量、分子质量、单糖组成和红外光谱特征进行分析，并运用小鼠单核巨噬细胞RAW264．7模型研究各组分的体外免疫调节活性。结果表明：PYP-2、PYP-3和PYP-4组分总糖含量分别为91．83％、96．93％和97．66％，糖醛酸含量分别为19．39％、23．77％和18．23％，硫酸基含量分别为18．84％、17．63％和18．41％，分子质量分别为478．6、314．4、417．3kD，且3种多糖均是由半乳糖、葡萄糖和木糖3种单糖以β-糖苷键链接的吡喃糖。3种多糖在25～250μg／mL质量浓度范围内能够显著促进小鼠腹腔巨噬细胞RAW264．7的增殖，增强其吞噬中性红能力，表现出显著的免疫调节活性。

Polysaccharides from Prophyra yezoensis （PYP） were extracted with papain and purified using DEAE cellulose-52 and Sephadex G-100 chromatography. Four fractions named as PYP-1, PYP-2, PYP-3 and PYP-4 were obtained, and their physicochemical properties including total sugar content, molecular weight, sulfate and uronic acid contents and monosaccharide composition were investigated. In addition, RAW264.7 macrophage cell model was employed to evaluate the immunomodulatory activity in vitro. Results showed that total sugar contents of PYP-2, PYP-3 and PYP-4 were 91.83%, 96.93% and 97.66%, respectively. Uronic acid contents were 19.39%, 23.77% and 18.23%, respectively, and sulfate group contents were 18.84%, 17.63% and 18.41%, respectively. All these three polysaccharides were composed of galactose, glucose and xylose with molecular weight of 478.6, 314.4 kD, and 417.3 kD, respectively. Pyranose ring structure and t-type glycosidic linkages were also found in them. PYP-2, PYP-3, and PYP-4 when used at a concentration ranging from 25 to 250μg/mL could significantly promote the proliferation and neutral red phagocytosis of RAW264.7 macrophage cells in vitro, suggesting the potential immunomodulatory activities of PYP-2, PYP-3, and PYP-4.