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11.
Heparin has been used as an anticoagulant drug for many years, but it has significant side ef fects. In the search for good substitutes, low molecular weight(MW) polysaccharides from S argassum fusiforme have been examined and confi rmed to possess biological activities. Here, S. fusiforme polysaccharides(SFP) were extracted and subjected to a hydrogen peroxide(H_2O_2) oxidation method for the preparation of low-MW SFP(LSFP). The effects of temperature, pH, and H_2O_2 concentration on the degradation process were also examined. Several LSFP of 36, 9, 5.7, and 2.7 kDa were obtained under different conditions, and their anticoagulant activities studied in vitro. The results showed that SFP and LSFP prolonged activated partial thromboplastin(APTT), prothrombin(PT) and thrombin times(TT) significantly, indicating that these low MW polysaccharides possessed anticoagulant activity in the intrinsic, extrinsic, and common coagulation pathways. As these ef fects were related to the MW of the polysaccharides in APTT and TT but not in PT, the contents of the monosaccharide fucose and sulfate and the polysaccharide MW could have exerted combined ef fects. The details of this mechanism require further verifi cation. 相似文献
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Although prebiotic activities of alginate and agar oligosaccharides isolated from seaweeds have been reported, it remains unknown whether seaweed polysaccharides have prebiotic activity. In this study, we isolated polysaccharides from four species of seaweeds, such as Grateloupia fi licina(GFP), Eucheuma spinosum(ESP), Ulva pertusa(UPP), and A scophyllum nodosum(ANP), and characterized their structures and prebiotic ef fects in vitro. The results showed that these polysaccharides were dif ferent in total sugar and sulfate contents as well as monosaccharide composition. GFP and ESP significantly promoted bifi dobacterium proliferation and 0.1% ESP and 0.4% GFP resulted in the highest proliferation rates of beneficial bacteria, whereas UPP and ANP inhibited the growth of beneficial bacteria at all tested concentrations(0.1%–0.5%). The different behaviors of the four seaweed-originated polysaccharides might be refl ected by differences in monosaccharide composition and structure. Therefore, polysaccharides isolated from GFP and ESP could be utilized as prebiotics. However, more studies must be carried out in vivo. 相似文献
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海蜇中常量和微量元素的同时测定 总被引：1，自引：0，他引：1
海蜇(Rhopilema esculentum Kishinouye),钵水母纲,根口水母,广泛分布于我国的沿海近岸,是我国传统渔业生产的主要大型经济水母[1].海蜇的营养十分丰富,除含有蛋白质、脂肪酸和维生素外,还含有大量的矿物质[2].海蜇的药用价值在我国早有记录[3],在韩国海蜇被作为减肥和美容的食品,而澳大利亚的土族人则用干海蜇粉治疗烫伤[4].近代研究表明海蜇有治疗高血压、慢性气管炎、哮喘、胃溃疡和单纯性甲状腺肿大的作用[5].美国Auburn大学的研究小组报道:Stomolophus meleagris水母的胶原质对实验鼠抗原引起的关节炎有一定的抑制作用[6]. 相似文献
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为了寻找安全有效的海洋生物保水剂，本研究以海洋生物多糖/寡糖为研究对象，经多糖筛选和单因素实验确定壳聚糖1号、壳聚糖2号和海藻酸钠的最佳添加量，采用响应面优化实验确定最优复配值为：壳聚糖1号0.29%，壳聚糖2号1.11%，海藻酸钠0.93%，在此条件下测得的鱼丸解冻失水率为1.46%±0.24%，结果表明该多糖复配组合对鱼丸制品具有较好的保水作用。通过扫描电镜观察多糖组鱼丸的微观结构，发现其结构致密，无较大孔隙。通过本实验的开展，能够为水产品的保水保鲜剂的开发提供新思路。 相似文献
16.
In this study, several methods were compared for the efficiency to concentrate venom from the tentacles of jellyfish Rhopilema esculentum Kishinouye. The results show that the methods using either freezing-dry or gel absorption to remove water to concentrate venom are not applicable due to the low concentration of the compounds dissolved. Although the recovery efficiency and the total venom obtained using the dialysis dehydration method are high, some proteins can be lost during the concentrating process. Comparing to the lyophilization method, ultrafiltration is a simple way to concentrate the compounds at high percentage but the hemolytic activities of the proteins obtained by ultrafiltration appear to be lower. Our results suggest that overall lyophilization is the best and recommended method to concentrate venom from the tentacles of jellyfish. It shows not only the high recovery efficiency for the venoms but high hemolytic activities as well. 相似文献
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甲壳素是一种天然高分子多糖，具有与纤维素相近的骨架结构，其资源丰富，用途广泛(方波，1998)。但由于分子内和分子间存在很强的氢键作用力，因而不能熔融，也不溶于普通溶剂(如水、乙醇等)(董炎明等，2002)，实际应用中较多的是其部分或全部脱乙酰化产物——壳聚糖。壳聚糖虽然可以溶于酸性水溶液，但不能直接溶于水中，且在酸性水溶液中不稳定，也不溶于一般的有机溶剂，这在很大程度上限制了它的应用(董炎明等，2002)。所以，水溶性壳聚糖衍生物的研制正成为一个新的研究方向。壳聚糖分子中C2位上的-NH2，C3、C6位上的-OH，均具有较强的反应活性，在适当条件下可进行多种化学修饰，如酰基化、羧烷基化、硫酸酯化、烷基化、羟烷基化及氰烷基化等。引入上述功能性基团，可增加壳聚糖的溶解性和功能性，拓宽了壳聚糖的应用范围。这些衍生物的制备研究已成为壳聚糖应用开发的主要方向之一。 相似文献
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The present work is the first report of the biochemical characterization of the venom from nematocysts of the jellyfish Rhopilema esculentum Kishinouye. The nematocysts were isolated by autolysis and centrifugation and separated by flow cytometry. Four types of
nematocysts were identified: mastigophores, euryteles, and atrichous and holotrichous isorhiza. SDS-PAGE and amino acid analyses
demonstrated that most of the proteins in the nematocyst extract were between 10 kDa and 40 kDa, and that glutamic acid was
the main amino acid. A hemolytic activity assay showed that the activity of the nematocyst venom (RNV) was strongest in Tris-HCl
buffer (50 mmol/L, pH 7.8, 5% glycerol, 0.5 mmol/L EDTA, 0.1 mol/L NaCl). The hemolytic activity was related to protein concentration
and the HU50 against chicken erythrocytes was 0.91 μg/mL. 相似文献
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甲壳质(chitin)，又名甲壳素，几丁质，主要存在于虾、蟹、蛹及昆虫等动物外壳中。其衍生物壳聚糖(chitosan)又名甲壳胺或脱乙酰甲壳素，是甲壳质经脱乙酰化反应制得的产物，是最基本、最重要的甲壳质衍生物。
壳聚糖具有良好的吸湿性、成膜性、气透性、降解性、生物相溶性、无毒副作用以及不污染环境的优良性质，广泛应用于环保、食品、化工、医药、纺织、造纸、卷烟、农业、化妆品、印染、生物医学、酶制剂、保健品、金属回收等许多行业中。因此甲壳质作为一种纯天然的自然资源，对其开发和应用具有极其深远的意义。但甲壳质及其壳聚糖的高度不溶性极大地限制了它们的应用，必须对它们进行化学深加工，或结构修饰，引入或改变其分子链上的某个基团，或者完全降解或部分降解其分子链，从而得到一些具有特殊性质、水溶性有所改善的衍生物产品来满足人们的使用需要，因此甲壳单糖随之问世。
D-氨基葡萄糖盐酸盐(GAH)是甲壳质或壳聚糖的降解产物，其结构为D-葡萄糖分子中C2-羟基被氨基所取代，因氨基显碱性，与盐酸结合成盐。D-氨基葡萄糖盐酸盐是重要的生化试剂和医药中间体，其用途十分广泛：对人体具有重要的生理功能，它参与肝肾解毒，发挥抗炎护肝的作用；它能促进抗生素药剂的注射功能，也可作为糖尿病患者的营养补助剂，大剂量使用对宿主组织无害，但对体内恶性细胞却是一种细胞毒；它促进人体黏多糖的合成，改善关节软骨的代谢及修复；此外，它还可作为化妆品和饲料的添加剂。目前，国内、外对D-氨基葡萄糖的需求日益增加。
本文论述了甲壳质和壳聚糖的制备技术，并着重研究了单糖的最优化制备方法，通过正交实验，进行了3因素6水平72(36×2)个实验；同时研究了抽滤工艺和脱色工艺对产品质量的影响，为今后高质量的生产D-氨基葡萄糖盐酸盐及工业化提供了技术指导。 相似文献
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