蜈蚣藻中一种硫酸半乳聚糖的分离纯化、结构鉴定及其抗新生血管生成活性

为了寻找多糖类血管生成抑制剂, 我们以蜈蚣藻(Grateloupia filicina)为原料, 经水提、醇沉、DEAE-Sepharose Fast Flow和Sepharose CL-6B凝胶柱层析分离纯化, 得到一个均一多糖(GFP15).采用HPGPC、糖组成分析、绝对构型测定、甲基化分析、IR和NMR等技术对GFP15进行结构鉴定.结果表明, GFP15为一琼胶和卡拉胶中间型的硫酸半乳聚糖, 主要由1,3连接的β-D-半乳糖和1,4连接的2,3位硫酸基双取代的α-D-半乳糖交替组成, 1,3连接β-D-半乳糖的4位和6位上分别有少量的硫酸基取代, 1,4连接的半乳糖有少量是α-L-半乳糖, 此外, 还有极少量的木糖、3,6-脱水半乳糖和6-甲基-半乳糖.利用鸡胚尿囊膜法(CAM)对GFP15进行抗新生血管生成活性评价, 结果显示, GFP15(100 μg/egg)能抑制尿囊膜新生血管的形成, 提示GFP15 作为一种多糖类血管生成抑制剂具有开发为抗肿瘤药物的潜在价值.

Sulfated Galactan from Grateloupia filicina: Isolation, Purification, Structure Characterization and Its Antiangiogenic Activity

Sulfated polysaccharides from marine algae attracted more and more attention as their diverse biological activities. Tumor neovascularization has become a new target for anti-cancer drugs, and antiangiogenic activities of sulfated polysaccharides have been increasingly reported in recent years. In order to discover polysaccharide-type angiogenic inhibitors, a homogenous sulfated galactan, GFP15, was obtained from Grateloupia filicina, by water extraction, DEAE-Sepharose Fast Flow and Sepharose CL-6B gel permeation chromatography. The structure of GFP15 was characterized with monosaccharide composition analysis, absolute configuration determination, methylation analysis, IR and NMR. The results consistently indicate that GFP15 was an agaran-carrageenan hybrid polysaccharide, composed of 3-linked β-D-galactose partially sulfated at positions O4 and O6, and 4-linked α-D-galactose 2,3-disulfate and α-L-galactose 2,3-disulfate. Small quantities of xylose, 3,6-anhydro-α-galactose and 6-methyl-galactose were also present. The antiangiogenic activity of GFP15 was evaluated via the chick chorioallantoic membrane(CAM) assay. GFP15(100 μg/egg) could reduced new vessel formation. These results indicate that as a potential angiogenesis inhibitor, GFP15 may be a good candidate for future development as an anti-cancer agent.