绿藻硫酸多糖SHW及其低分子量片段的结构及抗凝活性研究

Structure and anticoagulant activity of the green algal sulfated polysaccharide SHW and its low-molecular-weight fragments

目的对绿藻多糖SHW及其低分子量片段的结构及抗凝活性进行研究。方法通过热水提取、强阴离子交换色谱和凝胶渗透色谱,从绿藻硬毛藻中提取分离得到硫酸多糖SHW;通过可控酸解方法制备SHW低分子量片段;采用高效凝胶渗透色谱、高效液相色谱、红外光谱及甲基化方法对多糖结构进行表征;通过活化部分凝血活酶时间、凝血酶时间、凝血酶原时间研究多糖SHW及其低分子量片段体外抗凝血活性。结果多糖SHW及其低分子量片段主要由阿拉伯糖组成,含有少量半乳糖和氨基葡萄糖;糖链中阿拉伯糖主要以→4)-Arap-(1→和→3,4)Arap-(1→的形式存在,半乳糖以→4)-Galp-(1→形式存在,硫酸根主要位于→4)-Arap-(1→的C-3位。SHW及其低分子量片段A1~A6的分子量分别为492、200、170、100、26、14和10 kDa。SHW具有较高的抗凝血活性,且其抗凝活性随着其分子量的减少而降低。结论海藻多糖SHW是1种具有抗凝活性的新颖硫酸多糖,其抗凝活性与分子量密切相关。

Objective To study the structure and anticoagulant activity of the green algal sulfated polysaccharide SHW and its low-molecular-weight fragments.Methods Sulfated polysaccharide(SHW)was obtained from the green alga Chaetomorpha aerea by hot water,and further purified by strong anion exchange chromatography and gel permeation chromatography.The low-molecular-weight fragments of SHW(A1~A6)were prepared by controlled acid degradation.The structures of the polysaccharides were characterized by high performance gel permeation chromatography,high performance liquid chromatography,Fourier infrared spectroscopy and methylation analysis.Anticoagulant properties in vitro of SHW and A1~A6 were evaluated by studying the activated partial thromboplastin time,thrombin time and prothrombin time.Results SHW and its low-molecular-weight fragments were mainly composed of arabinose with small amounts of galactose and glucosamine.The arabinose in the polysaccharide chain was existed in the forms of→4)-Arap-(1→and→3,4)-Arap-(1→,and the galactose was existed as→4)-Galp-(1→.The sulfate ester was substituted at C-3 of→4)-Arap-(1→residues.The molecular weights of SHW and A1~A6 were 492,200,170,100,26,14 and 10 kDa,respectively.SHW had high anticoagulant activity.A decrease in the molecular weight of SHW was accompanied by a decrease in the anticoagulant activity.Conclusion SHW was a novel sulfated polysaccharide with anticoagulant activity,and its anticoagulant activity was closely related with molecular weight.