细茎石斛多糖DMP4a-1的结构特性及免疫活性研究

Study on structural characteristics and immunomodulatory activity of polysaccharide DMP4a-1 from Dendrobi-um moniliforme

目的研究从细茎石斛中分离纯化得到的酸性多糖DMP4a-1的结构性质,初步鉴定其免疫调节活性。方法 应用高效 凝胶渗透色谱(HPGPC),TLC,GC,GC．MS,IR,高碘酸氧化等方法进行组成结构分析,采用双抗夹心ELISA法检测巨噬细胞TNF-α 分泌水平、用CCK-8试剂进行脾淋巴细胞增殖实验。结果 细茎石斛水溶性酸性多糖DMP4a-1平均相对分子质量为3 049,主 要由葡萄糖,甘露糖,鼠李糖,阿拉伯糖和半乳糖组成,其分子摩尔数之比为2．873:2．850:1．762:1．279:l,糖链结构中存在1→ 4,1→3及1→6糖苷键,且摩尔数比为1．194:2．430:1。体外实验证明,DMP4a-1可明显刺激巨噬细胞分泌TNF-α,促进脾淋巴细 胞增殖。结论细茎石斛多糖DMP4a-1是一种β-D-吡喃杂多糖,在结构上与抗肿瘤多糖类似,富含1→3糖苷键,具有免疫增 强功能。

OBJECTIVE To investigate the structural feature and immunomodulatory activity of the water-soluble polysaccharide DMP4a-1 from Dendrobium moniliforrne （L.） Sw . METHODS The chemical structure of the polysaccharide DMP4a-1 was elucidated by periodate oxidation, HPGPC, TLC, GC, GC-MS and IR; TNF-a was quantified by sandwich ELISA, the proliferation of spleen lymphocyte was measured by CCK-8 reagent in vitro.RESULTS DMP4a-1 was composed of Gle-Man-Rha-Ara-Gal in a molar ratios of 2.873：2.850： 1.762：1.279： 1 with M： 3 049. They were （ 1→4, 1→3, 1→6） linked with glycosidic residues, in a ratio of 1.194： 2.430： 1. DMP4a-1 significantly stimulatd the secretion of TNF-α in maerophage and promoted the proliferation of lymphocyte from spleen in vitro. CONCLUSION Polysaeeharide DMP4a-1 consists of/β-D-pyranyl glycoside with （1→3）glycosidic bond, and markedly enhances immunological activity.