排序方式: 共有93条查询结果,搜索用时 46 毫秒
81.
Costa LS Fidelis GP Telles CB Dantas-Santos N Camara RB Cordeiro SL Costa MS Almeida-Lima J Melo-Silveira RF Oliveira RM Albuquerque IR Andrade GP Rocha HA 《Marine drugs》2011,9(6):952-966
Fucan is a term used to denominate a type of polysaccharide which contains substantial percentages of l-fucose and sulfate ester groups. We obtained five heterofucans from Sargassum filipendula by proteolytic digestion followed by sequential acetone precipitation. These heterofucans are composed mainly of fucose, glucose, glucuronic acid, galactose and sulfate. These fucans did not show anticoagulant activity in PT and aPTT tests. Their antioxidant activity was evaluated using the follow tests; total antioxidant capacity, scavenging hydroxyl and superoxide radicals, reducing power and ferrous ion [Fe(II)] chelating. All heterofucans displayed considerable activity, especially SF-1.0v which showed the most significant antioxidant potential with 90.7 ascorbic acid equivalents in a total antioxidant capacity test and similar activity when compared with vitamin C in a reducing power assay. The fucan antiproliferative activity was performed with HeLa, PC3 and HepG2 cells using MTT test. In all tested conditions the heterofucans exhibited a dose-dependent effect. The strongest inhibition was observed in HeLa cells, where SF-1.0 and SF-1.5 exhibited considerable activity with an IC50 value of 15.69 and 13.83 μM, respectively. These results clearly indicate the beneficial effect of S. filipendula polysaccharides as antiproliferative and antioxidant. Further purification steps and additional studies on structural features as well as in vivo experiments are needed to test the viability of their use as therapeutic agents. 相似文献
82.
83.
以海带(Laminaria japonica)为原料,采用阴离子交换和自由基氧化降解反应制备了不同分子量和硫酸根含量的岩藻聚糖硫酸酯,然后以血浆复钙时间(RT)、活化部分凝血活酶时间(APTT)、凝血酶原时间(PT)、凝血酶时间(TT)为指标,研究海带岩藻聚糖硫酸酯抗凝血活性的构效关系.结果表明,采用离子交换,可从海带糖提取物中分离出低硫大分子组分F-A和高硫大分子组分F-B.粗糖经自由基氧化降解,可得到分子量为1.5 kD和8.0 kD左右的低分子组分,实验重复性好,产物分子量集中,其中分子量8.0 kD左右的低分子组分硫酸根含量最高.抗凝血实验表明,岩藻聚糖硫酸酯能显著延长RT、APTT和TT,尤以高硫组分大分子F-B抗凝血效果最好,而对PT影响不大,说明岩藻聚糖硫酸酯对外源凝血系统影响很小,它的抗凝血活性主要是通过内源性凝血途径来实现的.岩藻聚糖硫酸酯分子量对抗凝血活性的影响要比硫酸根含量的影响更大,其抗凝血活性随着分子量的降低而显著降低.对于分子量相近的岩藻聚糖硫酸脂,硫酸根含量越高,则抗凝血活性越高.总之,岩藻聚糖硫酸酯分子量和硫酸根含量越高,其抗凝活性越高. 相似文献
84.
85.
用化学发光分析法研究了3种低分子量涨带岩藻聚糖硫酸酯(LMWF-M,LMWF-I,LMWF-IV)体外清除超氧阴离子自基基(O2^-)及羟基自同基(.OH)的作用,并观察了LMWF-M对高脂血症大鼠的抗氧化作用,结果表明阴离子分量海带岩藻聚糖硫酸酯组分均有清除活性氧自由基的能力,随体系中LMWF浓度的增加,其清除活氧自由基的能力增强,LMWF-I清除自同基的能力最强,它对O2^-的IC50为0.044mg.mL^-1,对.OH的IC50为0.062mg.mL^-1,,LWMF-M能显著降低高脂血症大鼠箅清和组织中LPO含量(P<0.01),增强SOD活力(P<0.01). 相似文献
86.
为探究苷苔Ecklonia cava岩藻聚糖硫酸酯粗品(EC-FUC)的组成结构,以产自韩国济州岛海岸的苷苔Ecklonia cava中提取的EC-FUC为原料,利用DEAE-Sepharose fast flow阴离子交换层析和Sephacryl S-300、S-400凝胶柱层析对EC-FUC进行分离纯化及分子量的测定,采用苯酚-硫酸法和明胶-Ba Cl2法分别测定纯化各组分的总糖含量及硫酸根含量,采用高效液相色谱法、红外光谱法、核磁共振波谱法分别测定各个纯化组分的单糖组成并分析多糖结构。结果表明:EC-FUC纯化后得到ECF-1、ECF-2和ECF-3组分,其总糖含量分别为41.7%、57.79%、75.78%,硫酸根含量分别为3.68%、3.41%、18.03%,回收率分别为6.27%、8.77%、16.19%,其相对分子质量分别为16 430、16 430、222 460;ECF-1单糖组成主要为葡萄糖,ECF-2单糖组成主要为甘露糖醛酸、葡萄糖醛酸和岩藻糖,ECF-3单糖组成主要为岩藻糖和葡萄糖醛酸;红外光谱分析显示,ECF-1、ECF-2和ECF-3硫酸基主要连接在岩藻糖的C2、C3位置;13C核磁共振分析显示,ECF-2中存在甘露糖醛酸,ECF-3在17.97×10-6处出现α-L-吡喃岩藻糖C6信号峰。本研究结果可为苷苔藻聚糖硫酸酯组成结构提供丰富的信息。 相似文献
87.
采用MTT方法考查不同浓度的马尾藻岩藻聚糖硫酸脂对HepG2细胞存活率的影响,进一步运用流式细胞仪和检测ROS含量探讨马尾藻岩藻聚糖硫酸酯抑制HepG2细胞增殖的机理。结果表明,在0.5~8.0 mg/mL内,HepG2细胞的存活率随着马尾藻岩藻聚糖硫酸脂浓度的升高呈下降趋势。研究发现,随着马尾藻岩藻聚糖硫酸脂浓度的增加,细胞内SubG1和G0/G1的细胞数量升高。而且,通过检测细胞内活性氧(Reactive oxygen species,ROS)含量,发现随着马尾藻岩藻聚糖硫酸脂浓度的增加,细胞内ROS含量显著升高。马尾藻岩藻聚糖硫酸脂抑制HepG2细胞增殖是通过诱导细胞内ROS的过量产生导致细胞发生凋亡和G0/G1阻滞。 相似文献
88.
从福建省沿海生长的海带中提取岩藻聚糖硫酸酯,采用截留分子量50、30、10ku的平板超滤膜进行梯度超滤,发现50ku以上占了提取的岩藻聚糖硫酸酯的(84.29±2.772)%。采用EDTA和盐酸处理分子量大于50ku的岩藻聚糖硫酸酯,结合超滤技术进行脱除重金属As和Pb元素的研究,分别用原子荧光光谱仪和电感耦合等离子质谱检测处理前后岩藻聚糖硫酸酯中重金属As和Pb元素的残留量。结果显示,超滤后岩藻聚糖硫酸酯的相对电导率明显降低;用SPSS13.0统计方法对数据进行t检验,结果表明,试验组与对照组存在显著性差异,即用超滤结合螯合方法能显著脱除岩藻聚糖硫酸酯中重金属As和Pb。 相似文献
89.
Tomohiro Osaki Koudai Kitahara Yoshiharu Okamoto Tomohiro Imagawa Takeshi Tsuka Yasunari Miki Hitoshi Kawamoto Hiroyuki Saimoto Saburo Minami 《Marine drugs》2012,10(11):2560-2570
We investigated the effect of fucoidan, a sulfated polysaccharide, on acceleration of healing of experimental cartilage injury in a rabbit model. An injured cartilage model was surgically created by introduction of three holes, one in the articular cartilage of the medial trochlea and two in the trochlear sulcus of the distal femur. Rabbits in three experimental groups (F groups) were orally administered fucoidan of seven different molecular weights (8, 50, 146, 239, 330, 400, or 1000 kD) for 3 weeks by screening. Control (C group) rabbits were provided water ad libitum. After the experimental period, macroscopic examination showed that the degree of filling in the fucoidan group was higher than that in the C group. Histologically, the holes were filled by collagen fiber and fibroblasts in the C group, and by chondroblasts and fibroblasts in the F groups. Image analysis of Alcian blue- and safranin O-stained F-group specimens showed increased production of glycosaminoglycans (GAGs) and proteoglycans (PGs), respectively. Some injured holes were well repaired both macroscopically and microscopically and were filled with cartilage tissues; cartilage matrices such as PGs and GAGs were produced in groups F 50, F 146, and F 239. Thus, fucoidan administration enhanced morphologically healing of cartilage injury. 相似文献
90.
Woo Jung Kim Joo Woong Park Jae Kweon Park Doo Jin Choi Yong Il Park 《Marine drugs》2015,13(7):4398-4417
The Search for enzyme activities that efficiently degrade marine polysaccharides is becoming an increasingly important area for both structural analysis and production of lower-molecular weight oligosaccharides. In this study, an endo-acting fucoidanase that degrades Miyeokgui fucoidan (MF), a sulfated galactofucan isolated from the sporophyll (called Miyeokgui in Korean) of Undaria pinnatifida, into smaller-sized galactofuco-oligosaccharides (1000–4000 Da) was purified from a marine bacterium, Sphingomonas paucimobilis PF-1, by ammonium sulfate precipitation, diethylaminoethyl (DEAE)-Sepharose column chromatography, and chromatofocusing. The specific activity of this enzyme was approximately 112-fold higher than that of the crude enzyme, and its molecular weight was approximately 130 kDa (FNase S), as determined by native gel electrophoresis and 130 (S1), 70 (S2) and 60 (S3) kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). The optimum pH and temperature of FNase S were pH 6.0–7.0 and 40–45 °C, respectively. FNase S activity was enhanced by Mn2+ and Na+ (115.7% and 131.2%), but it was inhibited by Ca2+, K+, Ba2+, Cu2+ (96%, 83.7%, 84.3%, and 89.3%, respectively), each at 1 mM. The Km, Vmax and Kcat values of FNase S on MF were 1.7 mM, 0.62 mg·min−1, and 0.38·S−1, respectively. This enzyme could be a valuable tool for the structural analysis of fucoidans and production of bioactive fuco-oligosaccharides. 相似文献