【作者】 蔡跃飘；

【导师】 薛长湖；

【作者基本信息】 中国海洋大学 ， 水产品加工与贮藏工程， 2005， 博士

【摘要】 岩藻聚糖硫酸酯是一种杂多糖,一般存在于褐藻和一些棘皮动物体中。近年来海洋药物方面的研究表明它有如抗凝血、抗肿瘤、抗病毒、抗溃疡等等多种活性,因此近年来对它研究逐渐增多。但其结构和组成随着提取来源的不同,往往有较大的差别。海带（Laminaria japonica）是海带科（Laminariaceae）的一种大型海藻,不但含有丰富的蛋白质、维生素和矿物质,也含有岩藻聚糖硫酸酯,具有较高的经济价值。我国目前已成为世界上海带生产养殖的第一大国家,年产量占世界海带产量的80%以上。但海带产业在我国却迟迟未能发展成为大产业,主要原因之一,就是产品单一、科研开发力度不够,产业总体上处于低水平、低附加值的阶段。为了促进海带产业以及整个海藻工业的发展,必须深入研究海带的综合利用,加快高附加值产品的开发。 海带岩藻聚糖硫酸酯已有不少关于它活性的报道,但对它的结构分析却很少,本文将试图对其结构进行分析。文中主要完成了以下工作: 1.通过酸提取、膜分离和乙醇沉淀法,制备得到岩藻聚糖硫酸酯粗品。利用Q-Sepharose FF阴离子交换树脂分级和凝胶色谱纯化,得到硫酸基含量不同的三个组分:F-0,F-1和F-2,得率分别为13.4%,34.8%,28.6%。经化学组成分析,这三个组分的硫酸基含量分别是7.6%,16.1%,30.5%;糖醛酸分别为20.8%,21.4%,8.4%。其中F-1是高糖醛酸组分,F-2是高硫组分。气相色谱分析表明这三种组分的单糖组成为岩藻糖、半乳糖、葡萄糖、甘露糖、鼠李糖和木糖。其中岩藻糖含量最高,分别达到40.7%,52.9%和62.5%。HPSEC法测定分子量表明F-1和F-2的数均分子量分别为150,700和160,000。 2.比较酸水解,酶水解和氧化水解的产物发现氧化水解更适合制备岩藻聚糖硫酸酯低聚糖。通过正交实验确定出最佳氧化水解条件为9%H₂O₂,60℃,反应6h。对氧化降解产物利用截留分子量为5,000（Da）的超滤膜分离,再用Bio-P4、P2进行进一步纯化,分别得到F-1b,F-1c和F-2b,F-2c。通过比较酸降解和氧化降解产物的硫酸基含量,发现氧化降解产物的硫酸基含量要高一些。更多还原

【Abstract】 Fucoidan is a kind of heteropolysaccharides. It’s generally found in brown seaweeds and some echinoderms, Recent researches in the marine drugs area show it has many biological activities, such as anticoagulant, anti-tumor, antiviral and anti-ulcer etc.. And the study on fucoidan is more and more concerned by researchers in recent years. Fucoidans extracted from different sources generally have different structure and constituents.Kelp (Laminaria japonica), a kind of large seaweed, is rich in protein, vitamins and minerals. It also contains fucoidans. China has become the largest country in the cultivation of kelp. Its annual production of kelp takes a share of over 80 percent of the whole world. But the kelp industry of China has never grown big. The main problem is that the production line is too simple. The entire industry is still on a low level. To accelate the development of the kelp industry of China, more effort should be conducted on the study of new high value products.Recently, many biological activities of fucoidans from Laminaria japonica have been studied, but reports on their structure are seldom seen. This paper tries to elucidate the structure of fucoidans from Laminaria japonica.1. Crude fucoidans were extracted from Laminaria japonica and then separated by anion-exchange chromatography on Q-Sepharose FF into three fractions, F-0, F-1 and F-2. Where F-l was the fractions with high uronic acids, and F-2 was high with sulfate ester. The yield ratios were 13.4%, 34.8%, and 28.6% respectively. Chemical composition analysis shows the contents of sulfate ester in the three fractions are 7.6%, 16.1%, and 30.5%. And the contents of uronic acids are 20.8%, 21.4%, 8.4%. QC analysis shows monosaccharides constituents in the three fractions are fucose, galactose, glucose, mannose, rhamnose, and xylose. Where fucose contents are the the highest, i.e. 40.7%, 52.9%, and 62.5% respectively. HPSEC shows the average molecular weights are 150,700 for F-l, and 160,000 for F-2.2. By comparing the hydrolysis products by methods of H2SO4, H2O2, and enzyme, H2O2 was found to be the best choice for the preparation of oligo-fucoidans. Through orthogonal experiments, the best hydrolysis condition was found to be 9%H2C>2, 60 °C, and 6h. Fucoidans were hydrolyzed with H2O2, separated by 5,000 Da. ultra-filtration membrane, and then purified by Bio-P4, and P2. The products were named F-lb, F-lc, F-2b, and F-2c. Comparison of the contents of sulfate ester in the products of acid degradation and H2O2 degradation showed the latter was higher.3. Anticoagulant experiments on the H2O2 degraded products with different molecular weights shows F-2 has strong anticoagulant, activity. And the 5,000~15,000 fraction of F-2 also shows strong activity, while the lower fraction does not. Compared with F-2, the F-l and its products are all less active. And the lower fraction of F-l even shows no activity at all.4. The structure of F-2, desulfated F-2, and F-2b were analyzed by IR, methylation, GC-MS, and NMR. The IR spectrum revealed that disulfated fucose exists in F-2. F-2 and its desulfated derivative were subjected to methylation analysis by GC-MS. The result showed that 1—>3-linkage is the major linkage pattern in fucose residues. Sulfate groups are substituted mainly at C-4 positions, lessly at C-2 of fucose residues, and some of fucose residues are disulfated at C-2, 4 positions. NMR showed F-2b is 1—>3 linked tetra-saccharides. It has fucose residues of two configurations, a and (3. And sulfate groups are substituted at C-4. The structure model of F-2b is -?a-L-Fucp-4(SO4))-(l->3)-(/3-L-Fucp-4(SO4))-(l-?3)-a-L-Flicp-(l-?3)-更多还原