褐藻糖胶的提取纯化及其抗凝血活性的研究

从海带中提取出的水溶性提取物，经超滤，醇析获得褐藻糖胶粗多糖，以DEAE-Sephrose Fast Flow离子交换层析分离纯化，得到了F1，F2和F3三个级分，这三个级分具有明显的抗凝血作用。尤其是F3级分，能显地延长激活部分凝血活酶时间和凝血酶时间。     

胶原/褐藻糖胶膜的制备及生物活性的研究

制备了一种新型具有生物活性的胶原/褐藻糖胶膜。采用FTIR分析了胶原与褐藻糖胶间离子键的形成,并分别采用体外凝血试验tAPTT、tTT、tPT和MTT染色法评价了其体外抗凝血活性和人脐静脉血管内皮细胞HUVEC生长增值效果。结果表明,tAPTT、tTT分别在不同浓度出现显著性差异,而tPT未出现显著性差异;胶原/褐藻糖胶膜比胶原膜的OD550nm增加得多,HUVEC增殖数量有大幅度提高,胶原中添加褐藻糖胶后促进了HUVEC的增殖。     

丝素褐藻糖胶共混膜的结构与热性能

丝素是蚕丝的主要成分，是人类最早应用的天然蛋白质之一，作为性能优良的天然纤维一直用于纺织行业．近年来，丝素膜由于具有良好的透气透氧性和较少的炎症反应，尤其是对活体组织具有良好的生物相容性的特点，在生物工程和生物医学领域得到广泛地研究，被用作酶的固定化材料和哺乳动物细胞培养的基质、体外组织工程支架和抗凝血材料等．     

褐藻糖胶的分离、化学修饰和清除羟自由基作用研究

用酸法提取褐藻糖胶,经乙醇初步分级得褐藻糖胶HD1和褐藻淀粉HD2;褐藻糖胶HD1经DEAE(二乙氨乙基)-纤维素柱层析,控制洗脱速度1.0mL/min,先经二次水洗脱,然后用0～1.5mol/LNaCl梯度洗脱;浓缩、透析,得褐藻糖胶HDⅠ和HDⅡ;用氯磺酸法合成了硫酸酯化褐藻糖胶HDSⅡ;红外光谱法确定了硫酸酯键的特征吸收。通过Fenton反应产生羟自由基模型,对比研究了褐藻多糖化学修饰前后体外抗氧自由基性质;褐藻糖胶HDⅡ经硫酸化修饰后、通过清除.OH自由基表明,褐藻糖胶组分HDⅡ、HDSⅡ均可作为自由基清除剂。     

不同提取方法所得褐藻糖胶的理化性质比较

通过各种理化性质的测定,对不同提取方法所得褐藻糖胶进行了分析,乙醇沉淀法的测定结果为:总糖含量(76.00±9.00)%、硫酸根含量(11.33±0.47)%、岩藻糖含量(35.60±4.20)%、重均/数均分子量(3.42×104)/(1.21×104);高分子电解质沉淀法的测定结果为:总糖含量(70.00±11.00)%、硫酸根含量(10.80±0.58)%、岩藻糖含量(35.15±2.85)%、重均/数均分子量(1.15×105)/(5.88×104)。高分子电解质沉淀法所得褐藻糖胶粗品和纯化后褐藻糖胶,其高分子电解质残留量分别为(0.12±0.038)%和(0.022±0.002)%。结果表明,乙醇沉淀法所得产品质量优于高分子电解质沉淀法,但是高分子电解质沉淀法具有工艺简单、成本低,更适于工业化生产等优点。     

玉米芯水溶性多糖的分离纯化和抗凝血活性研究

从玉米芯中提取到水提水溶性粗多糖,通过乙醇分级、冻融、凝胶过滤层析,生物测定导向等手段,分离到一种能延长体外凝血时间,而且具有外源抗凝血功能的多糖CCⅢ.CCⅢ对活化部分凝血酶原时间(APTT)无显著影响,但可显著延长体外抗凝血时间(PT).将CCⅢ纯化,经糖组成分析、甲基化、高碘酸氧化、Smith降解和GC-MS分析,确定该多糖结构为:β-(1→4)Glc,(1→3)Xyl构成主链,Glc在6-O处有分枝.平均每10个糖残基有1个分枝,支链由β-(1→3)Xyl,(1→3)Glc构成.     

杂合褐藻糖胶寡糖的制备及结构分析

采用热水提取法从海蒿子(Sargassum pallidum)中得到一个杂合的褐藻糖胶(SPF); 采用稀酸水解和低压凝胶渗透色谱(LPGPC)分离得到一系列杂合硫酸寡糖. 结合单糖组成、 甲基化和电喷雾碰撞诱导串联质谱(ES-CID-MS/MS)分析表明, 所得21个寡糖属于杂化岩藻寡糖硫酸酯, 主要由α1→3连接的Fuc及少量β1→4连接的Xyl和β1→6连接的Gal组成; 硫酸基取代位点主要存在于Fuc的C4或C2位、 Xyl的C2位和Gal的C4位; Fuc主要存在于寡糖的非还原端. 实验结果表明, ES-CID-MS/MS 技术可用于各种杂合褐藻糖胶寡糖的结构序列分析. 这些结构多样的硫酸寡糖可进一步点印到糖芯片上, 研究其与蛋白相互作用.     

基于脂质代谢组学研究褐藻糖胶对黄颡鱼幼鱼的影响

采用超高效液相色谱-四极杆-飞行时间质谱 (UPLC-Q-TOF-MS) 技术,结合多元变量数据分析方法,研究0.1%褐藻糖胶喂养黄颡鱼幼鱼1~8周的脂质代谢组学.通过不同喂养时间的黄颡鱼脂质成分的重要性(VIP)值和差异性(P)值,筛选出98个差异性代谢物,其中鉴定出与褐藻糖胶对黄颡鱼随喂养时间变化的影响有重要作用的11种脂质生物标志物,包括Lyso-PC 16∶0、PC 22∶6/16∶0、PE 22∶6/16∶0、PI 18∶0/22∶6、DAG 16∶0/16∶0、DAG 16∶0/18∶1、DAG 18∶1/18∶1、TAG 20∶5/16∶0/18∶3、TAG 20∶4/16∶1/18∶2、TAG 16∶0/18∶2/20∶5 和TAG 18∶2/14∶0/18∶1.研究表明,经0.1%褐藻糖胶喂养不同时期的黄颡鱼中Lyso-PC、PC、PE和PI的含量在第8周时达到最大值;DAG的含量呈现出先减少后增加的变化规律,而TAG的变化不定,TAG 18∶2/14∶0/18∶1、TAG 20∶5/16∶0/18∶3和TAG 20∶4/16∶1/18∶2的含量随着喂养褐藻糖胶时间的延长而增加,而TAG 16∶0/18∶2/20∶5呈减少的趋势.根据上述实验结果,推测褐藻糖胶可能通过调节脂质成分的含量来增加黄颡鱼幼鱼的免疫力.本研究结果为褐藻糖胶对黄颡鱼脂质代谢响应机理的影响的研究提供理论依据.     

枸杞子糖缀合物的LbGp4糖链的结构及其免疫活性的研究

枸杞子糖缀合物LbGp4经β-消除、柱层析分离后得到一条分子量高达180800的分支多糖化合物LbGp-OL.LbGp4-OL糖基组成分为n(Rha):n(Ara):n(Gal)=0.05:1.33:1，根据甲基化、部分酸水解及^1HNMR、^13CMR分析，确定了其主要的结构，并对LbGp4和LbGp4-OL的免疫活性进行了研究。     

氮芥苯甲酸氧化二丁基锡复合物的合成、晶体结构及其体外抗癌活性研究

Di-n-butyltin oxide reacted with p-[N,N-bis（2-chloroethyl）amino]benzoic acid to yield the compounds {{4-[（ClCH2CH2）2N]C6H4COOSnBu2}2O}2 （1） and {4-[（ClCH2CH2）2N]C6H4COO}2SnBu2 （2）, which have been characterized by IR and ^1H NMR spectra. The X-ray diffractional studies of 1 reveal the structure of the molecule to be a dimer, in which the two Bu2Sn groups were linked via two bridging oxygen atoms to form a central Bu4Sn2O2 unit. And the tin atom adopts two carbons from two n-butyl groups and three oxygen atoms from the acid and the bridging oxygen. In vitro test showed compound 1 to exhibit high cytotoxicity against P388 and HL-60 cell lines.     

新型苯并咪唑衍生物的合成及其抗凝血活性

以3-［(3-氨基-4-甲基氨基苯甲酰)吡啶-2-基氨基］丙酸乙酯为原料,与4-氰基-3-氟苯取代基乙酸经环化反应制得3-【【2-｛［(4-氰基-3-氟苯取代基）甲基］-1-甲基-1-H-苯并咪唑-5-基｝羰基】吡啶-2-基】氨基丙酸乙酯（3a, 3e）; 3经水解和酰胺化反应制得3-【【【2-｛［(4-氰基-3-氟苯基)取代基］甲基｝-1-甲基-1H-苯并咪唑-5-基】羰基】吡啶-2-基氨基】丙酰取代胺基（6a~6h）;6与乙酰氧肟酸经环合反应合成了8个新型的苯并咪唑衍生物（7a~7h）,其结构经1H NMR和HR-ESI-MS表征。抗凝血活性结果表明： 7a和7c的抗凝血活性最好,其aPTT值分别为(83.1±4.2) s和(80.7±2.9) s,优于阳性对照药达比加群酯(75.3±2.1)s。     

Antioxidant and Antisteatotic Activities of Fucoidan Fractions from Marine and Terrestrial Sources

Fucoidan is a fucose-rich sulfated polysaccharide typically found in the cell wall of marine algae but also recently isolated from terrestrial sources. Due to a variety of biological activities, including antioxidant properties, fucoidan exhibits an attractive therapeutic potential against a wide array of metabolic diseases associated with oxidative stress. We used FTIR, ¹H NMR and ¹³C NMR spectroscopy to investigate the structural features of a fucoidan fraction extracted from the brown alga Cystoseira compressa (CYS). The antioxidant potential of CYS was measured by DPPH, ABTS and FRAP assays, which revealed a radical scavenging capacity that was confirmed in in vitro cellular models of hepatic and endothelial cells. The same antioxidant effects were observed for another fucoidan fraction previously identified in the terrestrial tree Eucalyptus globulus (EUC). Moreover, in hepatic cells, CYS and EUC exhibited a significant antisteatotic action, being able to reduce intracellular triglyceride content through the regulation of key genes of hepatic lipid metabolism. EUC exerted stronger antioxidant and antisteatotic effects as compared to CYS, suggesting that both marine and terrestrial sources should be considered for fucoidan extraction and therapeutic applications.     

Antioxidant and Antisteatotic Activities of a New Fucoidan Extracted from Ferula hermonis Roots Harvested on Lebanese Mountains

Fucoidan is a fucose-rich sulfated polysaccharide with attractive therapeutic potential due to a variety of biological activities, including antioxidant action. Fucoidan is typically found in the cell wall of marine brown algae, but extra-algal sources have also been discovered. In the present work, for the first time we extracted a water soluble fucoidan fraction from the roots of the terrestrial shrub Ferula hermonis. This fucoidan fraction was termed FUFe, and contained fucose, glucose, sulfate, smaller amounts of monosaccharides such as galactose and mannose, and a minor quantity of proteins. FUFe structural features were investigated by FTIR, ¹H NMR and ¹³C NMR spectroscopy. The antioxidant property of FUFe was measured by DPPH, ABTS and FRAP assays, which revealed a high radical scavenging capacity that was confirmed in in vitro cellular models. In hepatic and endothelial cells, 50 μg/mL FUFe could reduce ROS production induced by intracellular lipid accumulation. Moreover, in hepatic cells FUFe exhibited a significant antisteatotic action, being able to reduce intracellular triglyceride content and to regulate the expression of key genes of hepatic lipid metabolism. Altogether, our results candidate FUFe as a possible bioactive compound against fatty liver disease and related vascular damage.     

Rheological Study on Polypropylene/Cycloolefin Copolymer Blends

Summary: Polypropylene, cycloolefin copolymer and their blends were characterized by means of melt flow analysis and capillary rheometry at temperatures between 190 and 230 °C in order to shed more light on COC fiber formation obtained in injection molding process. Melt viscosity and its activation energy as functions of blend composition show negative deviation from the expected additivity (Negative Deviating Blends). The COC/PP viscosity ratio increases with shear rate, but decreases with temperature. High temperature, low viscosity ratio and high shear rate seem to be favorable for fiber formation. Glass transition (from the reversible heat flow curve of modulated DSC) of dumbbell specimens produced by injection molding at 230 °C with COC minor component was 2–4 °C higher than that of grinded pellets obtained from mixing at 190 °C.     

纳米稀土氧化物/硫酸酯化壳聚糖杂化材料的制备及其抗凝血性能研究

利用接枝的方法制备了4 种纳米RE₂O₃/硫酸酯化壳聚糖杂化材料(Nd₂O₃-TDI-CS, Eu₂O₃-TDI-CS, La₂O₃-TDI-CS, Sc₂O₃-TDI-CS, TDI=甲苯二异氰酸酯, CS=壳聚糖), 用红外光谱、热重分析和扫描电镜表征了产物, 结果表明壳聚糖接枝于经过活化后的纳米氧化物表面. 抗凝血实验结果和复钙实验结果说明制备的4种杂化材料比纳米稀土氧化物具有更好的抗凝血性能.     

Anticancer,Anticoagulant, Antioxidant and Antimicrobial Activities of Thevetia peruviana Latex with Molecular Docking of Antimicrobial and Anticancer Activities

Natural origin molecules represent reliable and excellent sources to overcome some medicinal problems. The study of anticancer, anticoagulant, and antimicrobial activities of Thevetia peruviana latex were the aim of the current research. An investigation using high-performance liquid chromatography (HPLC) revealed that the major content of the flavonoids are rutin (11.45 µg/mL), quersestin (7.15 µg/mL), naringin (5.25 µg/mL), and hisperdin (6.07 µg/mL), while phenolic had chlorogenic (12.39 µg/mL), syringenic (7.45 µg/mL), and ferulic (5.07 µg/mL) acids in latex of T. peruviana. Via 1,1-diphenyl-2- picrylhydrazyl (DPPH) radical scavenging, the experiment demonstrated that latex had a potent antioxidant activity with the IC₅₀ 43.9 µg/mL for scavenging DPPH. Hemolysis inhibition was 58.5% at 1000 µg/mL of latex compared with 91.0% at 200 µg/mL of indomethacin as positive control. Negligible anticoagulant properties of latex were reported where the recorded time was 11.9 s of prothrombin time (PT) and 29.2 s of the activated partial thromboplastin time (APTT) at 25 µg/mL, compared with the same concentration of heparin (PT 94.6 s and APPT 117.7 s). The anticancer potential of latex was recorded against PC-3 (97.11% toxicity) and MCF-7 (96.23% toxicity) at 1000 μg/mL with IC₅₀ 48.26 μg/mL and 40.31 µg/mL, respectively. Disc diffusion assessment for antimicrobial activity recorded that the most sensitive tested microorganisms to latex were Bacillus subtilis followed by Escherichia coli, with an inhibition zone (IZ) of 31 mm with minimum inhibitory concentration (MIC) (10.2 μg/mL) and 30 mm (MIC, 12.51 μg/mL), respectively. Moreover, Candida albicans was sensitive (IZ, 28 mm) to latex, unlike black fungus (Mucor circinelloides). TEM examination exhibited ultrastructure changes in cell walls and cell membranes of Staphylococcus aureus and Pseudomonas aeruginosa treated with latex. Energy scores of the molecular docking of chlorogenic acid with E. coli DNA (7C7N), and Rutin with human prostate-specific antigen (3QUM) and breast cancer-associated protein (1JNX), result in excellent harmony with the experimental results. The outcome of research recommended that the latex is rich in constituents and considered a promising source that contributes to fighting cancer and pathogenic microorganisms.     

HDPE／NBR共混物结构和性能的研究

本文对高密度聚乙烯(HDPE)/丁腈橡胶(NBR)共混物的组成、结构、性能和相互作用进行了研究。实验结果表明:少量的NBR能大幅度提高HDPE的冲击韧性和耐环境应力开裂性能。WAXD显示NBR在共混物中呈现一定程度的取向;TEM显示NBR能以平均粒径为0.2 μm的尺寸分散于HDPE中,且形成较牢固的结合;DMA分析发现HDPE与NBR间相互作用而引起α、γ、T_(?)转变温度发生变化。本文对HDPE与NBR相互作用的机理进行了讨论。     

Influence of Reactive Compatibilization on the Morphology of Polypropylene/Polystyrene Blends

To study the efficiency of different mechanisms for reactive compatibilization of polypropylene/polystyrene blends (PP/PS blends), main chain or terminal-functionalized PP and terminal-functionalized PS have been synthesized by different methods. While the in-situ block and graft copolymer formation results in finer phase morphologies compared to the corresponding non-reactive blends, the morphology development in the ternary blend system PP/PS + HBP (hyperbranched polymer) is a very complex process. HBP with carboxylic acid end groups reacts preferably with the reactive sites of the oxazoline functionalized PS (PS-Ox) and locates mainly within the dispersed PS-Ox phase. A bimodal size distribution of the PS-Ox particles within the oxazoline modified PP (PP-Ox) matrix phase is observed with big PS-Ox particles (containing the HBP as dispersed phase) and small PS-Ox particles similar in size to the unimodal distributed particles in the non-reactive PP-Ox/PS-Ox blends. Factors influencing the morphology are discussed.     

DSC and p-V-T Study of PVC/PMMA Blends

Poly(vinyl chloride)/Poly(methyl methacrylate) — PVC/PMMA — blends were investigated by comparative p-V-T and differential scanning calorimetry (DSC) measurements. The study was concentrated on the glass transition range of the blends, and it was found that the blends are characterized by a single glass transition temperature suggesting miscibility of the blend components. It is shown that the glass temperature of the blends increases with both increasing heating rate and pressure. In parallel hereto one observes a decrease in the volume expansion coefficients, which is more accentuated for the polymeric melts than for the polymeric glasses. The dependence of the glass temperature on the composition of the polymer blends shows a sigmoidal behaviour which is due to the fact that positive deviations of the glass temperature from values predicted by additivity rules are observed in the high PVC concentration range, whereas in the high PMMA range negative deviations occur. This suggests a denser packing of the blends and thus a stronger interaction between the blend components in the high PVC concentration range. These packing differences increase with increasing pressure and decreasing heating rate and are generally more accentuated for the glass temperatures evaluated from p-V-T measurements.This revised version was published online in November 2005 with corrections to the Cover Date.     

The Ameliorative Effects of Fucoidan in Thioacetaide-Induced Liver Injury in Mice

Liver disorders have been recognized as one major health concern. Fucoidan, a sulfated polysaccharide extracted from the brown seaweed Fucus serratus, has previously been reported as an anti-inflammatory and antioxidant. However, the discovery and validation of its hepatoprotective properties and elucidation of its mechanisms of action are still unknown. The objective of the current study was to investigate the effect and possible modes of action of a treatment of fucoidan against thioacetamide (TAA)-induced liver injury in male C57BL/6 mice by serum biochemical and histological analyses. The mouse model for liver damage was developed by the administration of TAA thrice a week for six weeks. The mice with TAA-induced liver injury were orally administered fucoidan once a day for 42 days. The treated mice showed significantly higher body weights; food intakes; hepatic antioxidative enzymes (catalase, glutathione peroxidase (GPx), and superoxide dismutase (SOD)); and a lower serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and C-reactive protein (CRP) levels. Additionally, a reduced hepatic IL-6 level and a decreased expression of inflammatory-related genes, such as cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase (iNOS) mRNA was observed. These results demonstrated that fucoidan had a hepatoprotective effect on liver injury through the suppression of the inflammatory responses and acting as an antioxidant. In addition, here, we validated the use of fucoidan against liver disorders with supporting molecular data.