Anticoagulant, Antioxidant and Antitumor Activities of Heterofucans from the Seaweed Dictyopteris delicatula

In the present study, six families of sulfated polysaccharides were obtained from seaweed Dictyopteris delicatula by proteolytic digestion, followed by acetone fractionation and molecular sieving on Sephadex G-100. Chemical analyses demonstrated that all polysaccharides contain heterofucans composed mainly of fucose, xylose, glucose, galactose, uronic acid, and sulfate. The fucans F0.5v and F0.7v at 1.0 mg/mL showed high ferric chelating activity (～45%), whereas fucans F1.3v (0.5 mg/mL) showed considerable reducing power, about 53.2% of the activity of vitamin C. The fucan F1.5v presented the most prominent anticoagulant activity. The best antiproliferative activity was found with fucans F1.3v and F0.7v. However, F1.3v activity was much higher than F0.7v inhibiting almost 100% of HeLa cell proliferation. These fucans have been selected for further studies on structural characterization as well as in vivo experiments, which are already in progress.     

褐藻多糖硫酸酯/甲基丙烯酸甲酯接枝聚合及抗凝血性能研究

研究了Cu(Ⅱ)离子存在时,褐藻多糖硫酸酯与甲基丙烯酸甲酯(MMA)的接枝聚合反应。主要探讨了V(MMA)/V(H2O)、Cu(Ⅱ)浓度、反应时间、温度对接枝率的影响。采用FT-IR对接枝共聚物进行了表征。接枝共聚物的体外抗凝血活性采用部分凝血活酶时间(APTT)、凝血活酶时间(PT)、凝血酶时间(TT)来评价。结果表明,褐藻多糖硫酸酯的水溶液在Cu(Ⅱ)离子存在时,可以引发MMA的自由基聚合反应。当褐藻多糖硫酸酯的质量浓度为5 6g/L,V(MMA)/V(H2O)=0 20,Cu(Ⅱ)浓度为3 26mmol/L,反应温度85℃,反应时间为3h时,接枝率为197.0%。APTT、TT、PT实验证明,接枝产物的APTT、TT比空白对照物分别延长20s和5s以上,具有抗凝血性能。     

The effect of dietary Laminaria‐derived laminarin and fucoidan on nutrient digestibility,nitrogen utilisation,intestinal microflora and volatile fatty acid concentration in pigs

BACKGROUND: In experiment 1, 30 boars were assigned to one of five treatments (n = 6): T1, 0 g kg^?1 seaweed extract (SWE); T2, 0.7 g kg^?1 SWE; T3, 1.4 g kg^?1 SWE; T4, 2.8 g kg^?1 SWE and T5, 5.6 g kg^?1 SWE. The extract contained laminarin and fucoidan only and was extracted from Laminaria spp. In experiment 2, 28 boars were assigned, in a 2 × 2 factorial to one of four treatments (n = 7): T1, control; T2, control plus 300 mg laminarin; T3, control plus 240 mg fucoidan; T4, control plus 300 mg laminarin and 240 mg fucoidan kg^?1 diet. RESULTS: In experiment 1 there was a response to SWE on colonic Bifidobacterium spp. (P < 0.01 quadratic), Enterobacterium spp. (quadratic P < 0.05) and on caecal Enterobacterium spp. (quadratic P < 0.05). In experiment 2 there was an interaction (P < 0.05) between laminarin and fucoidan supplementation on Enterobacterium spp. in the proximal and distal colon. Pigs offered laminarin had reduced Enterobacterium spp. compared with pigs offered the control diet. However, the combination of laminarin and fucoidan had increased Enterobacterium spp. compared with alone. Pigs offered diets containing fucoidan had increased Lactobacilli spp. in the proximal colon (P < 0.05) and distal colon (P < 0.001) compared with non‐fucoidan diets. CONCLUSION: Overall, the reductions in intestinal Enterobacterium spp. and increases in Lactobacilli spp. obtained suggest that laminarin and fucoidan may provide a dietary means to improve gut health in pigs. Copyright © 2009 Society of Chemical Industry     

羊栖菜褐藻糖胶的分级纯化和结构分析

从浙江洞头产羊栖菜中提取得到的褐藻糖胶,经DEAESepharoseCL 6B柱层析得F1、F2和F33个组分,F3又经SepharoseCL 6B柱层析得F31、F32和F333个级分.经凝胶过滤色谱检测,F31、F32和F33为均一组分.化学组成分析表明,这5个级分均为岩藻糖、半乳糖和甘露糖等糖基组成的杂多糖,并含有硫酸酯、糖醛酸以及少量的蛋白质,相对分子质量范围为2.5×104～9.5×105.F33中氮的质量分数为2%,氨基酸分析和紫外扫描表明氮大部分可能来自核酸.F32的硫酸酯对碱基本稳定,表明大部分硫酸酯位于单糖残基的垂直位置.     

岩藻聚糖硫酸酯的研究进展

岩藻聚糖硫酸酯为含有硫酸基团的水溶性杂多糖,结构复杂,具有很多生物活性,包括抗氧化、降血脂、降血糖、抗炎、抗凝血、抗病毒、免疫调节等,使其在功能性食品、健康食品等领域有广阔的应用前景,在医药领域也有很大的应用潜力。不同的原料及其提取分离纯化的方法对其结构均有一定的影响,进而影响到其生物活性。且由于其结构的复杂性,对岩藻聚糖硫酸酯结构的解析方法也成为了研究重点。本文对岩藻聚糖硫酸酯的提取、分离纯化、结构分析及生物活性的研究进展进行了综述,并对岩藻聚糖硫酸酯在健康领域的应用现状进行了分析,以期为岩藻聚糖硫酸酯的研究与应用提供参考。     

岩藻聚糖硫酸酯的硫酸化修饰对其生物活性的影响

岩藻聚糖硫酸酯是一种硫酸化多糖,因其具有多种生物活性而得到广泛的研究,有研究表明岩藻聚糖硫酸酯的生物活性与其硫酸基团含量与位置息息相关。因此,对岩藻聚糖硫酸酯进行硫酸化修饰将有利于提高其生物活性。简述了硫酸基团对岩藻聚糖硫酸酯活性的影响以及岩藻聚糖硫酸酯的硫酸化方法,介绍了硫酸化修饰后的岩藻聚糖硫酸酯生物活性的变化,以期为岩藻聚糖硫酸酯硫酸化修饰的应用与发展提供理论参考。     

Inhibitory effects of fucan sulfates on enzymatic hydrolysis of starch

The effect of fucoidan and its oversulfated derivative on starch digestibility was investigated by determining the enzymatic reaction kinetics and their inhibitory activity against α-amylase and amyloglucosidase. After the α-amylase hydrolysis, the produced reducing sugars of the buckwheat starch (BW, 2.0-3.0 g/100 mL) and those of the blends of BW with low levels of native fucoidan (NF, 0.5-1.0 g/100 mL) and oversulfated fucoidan (OSF, 0.5-1.0 g/100 mL) were in the range of 440-450 mg/g starch. The addition of NF and OSF did not significantly influence the α-amylolysis. The hydrolysis of the starch and the fucoidan blends using both α-amylase and amyloglucosidase was decreased to 12% by the addition of 1.0 g/100 mL OSF, while only 5% reduction of the starch hydrolysis by 1.0 g/100 mL NF. The inhibitory activity of NF on amyloglucosidase was negligible, but that of OSF on amyloglucosidase was considerable up to 21.2% at the concentration of 10 mg/mL with non-competitive inhibition mechanism. It was suggested that the substantial reduction of starch hydrolysis by the addition of OSF may be caused by a direct inhibition of amyloglucosidase activity, implying a possible application of OSF as an enzyme inhibitor.     

海带岩藻多糖的抗脂质过氧化作用研究

用稀酸浸提和乙醇沉淀的方法提取海带岩藻多糖(Laminaria japonica fucoidan,LJF).采用体外实验研究LJF-2对H2O2诱导红细胞氧化溶血的抑制作用以及对小鼠肝匀浆脂质过氧化的保护作用,以此来评价LJF-2的抗脂质过氧化作用效果;结果表明,LJF-2对H2O2诱导的小鼠红细胞氧化溶血以及小鼠肝匀浆脂质过氧化具有明显的保护作用,且与浓度呈一定的量效关系.当浓度为0.54g/L时,对H2O2诱导红细胞氧化溶血的抑制率为50.32％,对小鼠肝匀浆脂质自发性过氧化的抑制率为28.24％.表明LJF-2具有显著的体外抗氧化活性.     

Fucoidans as Potential Therapeutics for Age-Related Macular Degeneration—Current Evidence from In Vitro Research

Age-related macular degeneration (AMD) is the major reason for blindness in the industrialized world with limited treatment options. Important pathogenic pathways in AMD include oxidative stress and vascular endothelial growth factor (VEGF) secretion. Due to their bioactivities, fucoidans have recently been suggested as potential therapeutics. This review gives an overview of the recent developments in this field. Recent studies have characterized several fucoidans from different species, with different molecular characteristics and different extraction methods, in regard to their ability to reduce oxidative stress and inhibit VEGF in AMD-relevant in vitro systems. As shown in these studies, fucoidans exhibit a species dependency in their bioactivity. Additionally, molecular properties such as molecular weight and fucose content are important issues. Fucoidans from Saccharina latissima and Laminaria hyperborea were identified as the most promising candidates for further development. Further research is warranted to establish fucoidans as potential therapeutics for AMD.