魔芋多糖硫酸酯化工艺优化研究

采用氯磺酸—吡啶法合成硫酸酯化魔芋多糖,单因素试验研究氯磺酸用量、反应时间、反应温度等因素对魔芋多糖硫酸酯化取代度的影响。正交试验,以魔芋多糖硫酸酯取代度作为考察指标,优化出最佳硫酸酯化工艺:氯磺酸用量为6mL;反应温度为50℃,反应时间为2h,在此条件下魔芋多糖的酯化度达到1.12。     

白沙参多糖与真鱿多糖的对比研究

采用蛋白酶水解白沙参与真鱿软骨,从组织中释放出多糖糖链,乙醇沉淀去除蛋白质,得到白沙参多糖与真鱿多糖,检测两种多糖中硫酸软骨素的二糖组分、多糖分子量及其抗凝活性。结果表明,白沙参多糖与真鱿多糖中硫酸软骨素均含有硫酸软骨素E二糖单位,在硫酸软骨素中的含量分别为34.8%和31.1%,两种硫酸软骨素分子量分别为105 000和259 000。两种多糖的硫酸化程度高,硫酸基含量分别为13.4%和10.2%。白沙参多糖与真鱿多糖均具有一定的抗凝活性,白沙参多糖的抗凝活性更高。     

羊栖菜褐藻多糖的提取及抗肿瘤活性

褐藻多糖是一种天然的硫酸杂多糖,是羊栖菜多糖中最具药理活性的成分,在抗肿瘤、抗氧化、增强免疫力、抗炎等多方面有着重要的作用。羊栖菜多糖的药理活性与其褐藻多糖的含量密切相关,褐藻多糖的硫酸化程度越高,发挥的作用越强。本文就褐藻多糖的提取工艺及其抗肿瘤活性进行讨论,希望能对进一步的深入研究提供参考。     

活性多糖构效关系研究评述

从结构与活性、理化性质与活性两个角度分别对活性多糖的构效关系进行论述。影响多糖生物学活性的结构因素包括多糖的主链性质、支链性质和多糖分子的高级结构 ,其中多糖主链的糖单元组成、糖苷键类型均直接决定多糖的活性 ,多糖支链的类型、聚合度、支链在多糖链上的分布及其取代度决定了多糖活性大小 ,多糖分子的高级结构如链的柔韧性和空间构像与多糖的活性紧密相关。多糖的理化性质如分子质量、溶解度和黏度等在一定程度上影响多糖活性的发挥     

拐枣中多糖的提取与含量测定

提取了拐枣中的活性多糖(非淀粉多糖)，并用蒽酮-硫酸比色法测定其多糖含量。测得多糖含量为13．83％，检测波长为568nm。回收率为99．20％，RSD=1．13％，实验结果表明，此方法简便、重现性和稳定性好。     

黄柏多糖的含量测定及抗氧化活性研究

目的对中药黄柏中多糖成分进行含量测定并研究其抗氧化能力。方法采用水提醇沉法制备黄柏多糖,苯酚-硫酸法测定多糖含量;用清除DPPH自由基、羟基自由基的能力来评价黄柏多糖的体外抗氧化活性。结果葡萄糖浓度在0.0159～0.03582mg·mL~(-1)范围内呈现良好的线性关系(r=0.9954);黄柏多糖的总糖含量为37.85%。黄柏多糖对DPPH自由基和羟基自由基清除能力较好,清除率呈量效关系。结论苯酚-硫酸法结果准确,重复性好,可以用于黄柏多糖的含量测定,同时药理活性实验证明黄柏多糖具有良好的抗氧化活性。     

不同来源猫爪草多糖质量分数测定及其抗氧化活性研究

以猫爪草为材料，研究不同提取时间、液料比、提取温度对猫爪草多糖质量分数的影响。在单因素试验的基础上，以猫爪草的多糖质量分数作为响应值，运用响应面法对猫爪草多糖提取条件进行优化。采用苯酚-硫酸法测定10个不同来源猫爪草药材中多糖的质量分数，并利用猫爪草多糖对DPPH的清除活性评价其抗氧化作用。结果表明：超声提取猫爪草多糖的最佳条件是提取时间41min，液料比15∶1mL·g^-1，提取温度84.6℃。不同来源猫爪草多糖的质量分数和抗氧化活性差异明显，其中河南信阳淮滨多糖质量分数最高，为72.72 mg·g^-1,IC50为2.6 mg·mL^-1，且猫爪草多糖对DPPH的清除能力与多糖质量分数呈正相关性。     

褐藻多糖硫酸酯的生物活性及应用前景

褐藻多糖硫酸酯是褐藻的重要活性成分,可用于药品、保健品、食品和化妆品等领域。介绍了近年来褐藻多糖硫酸酯的生物活性研究进展,详细讨论了其抗凝血、抗肿瘤、免疫调节、抗炎等作用和工业应用前景。     

款冬花磷酸酯多糖合成工艺研究

本研究以款冬花多糖为原料，采用混合磷酸盐法，制备款冬花磷酸酯多糖。以磷酸基的取代度（DS）为指标，在单因素实验的基础之上，采用响应面法对款冬花多糖磷酸酯化的制备工艺条件进行优化。并且对款冬花磷酸酯多糖清除DPPH?自由基的活性进行了初步研究。研究结果表明，最优合成工艺条件：反应时间6.03h，反应温度86℃，尿素用量14.25%，混合磷酸盐质量比为2.0，混合磷酸盐与款冬花多糖质量比为1.5。按此工艺条件，款冬花多糖磷酸酯中磷酸基团的取代度DS的平均值为0.697，且其清除DPPH?自由基的活性有所提高。     

茯砖茶茶多糖乙酰化修饰及其降血糖活性研究

以水提醇沉法制得伏砖茶多糖,以乙酸酐制备乙酰化伏砖茶多糖并测定取代度,采用体外化学模型研究伏砖茶多糖对α-淀粉酶、α-葡萄糖苷酶抑制活性。实验结果表明:伏砖茶多糖的提取率为4.62%,含量为68.72%,乙酰化茯砖茶多糖的取代度为0.214。4.0 mg/mL的茯砖茶多糖和乙酰化茶多糖对α-淀粉酶的抑制率分别为92.3%和96.8%;0.18 mg/mL的茯砖茶多糖和乙酰化茶多糖对α-葡萄糖苷酶的抑制率分别为90.3%和92.2%。两种多糖对两种酶均具有剂量依赖性抑制活性,乙酰化茶多糖抑制活性高于非乙酰化茶多糖,说明乙酰化修饰能增加茶多糖的降血糖活性。     

Recent Advances in Artificially Sulfated Polysaccharides for Applications in Cell Growth and Differentiation,Drug Delivery,and Tissue Engineering

Artificially sulfated polysaccharides, as the mimetics of native heparin and heparan sulfate, are important bioactive compounds, since they show great potential for tuning crucial biological activities within living organisms. Herein, we summarize progress in the development of artificially sulfated polysaccharides, such as cellulose sulfate, chitosan sulfate, and other sulfated polysaccharides, with a particular focus on the fields of biomedical and bioengineering applications in the past ten years. Their effects on cell growth and differentiation, but also as building blocks for drug carriers and medical implants, are emphasized.     

以鸡胸软骨为原料提取硫酸软骨素的研究

以鸡胸软骨为原料,在60℃下用木瓜蛋白酶水解除去蛋白质,再用乙醇沉淀获得鸡胸软骨多糖。色谱分析和聚丙烯酰胺凝胶电泳鉴别显示,鸡胸软骨多糖主要是硫酸软骨素,表明鸡胸软骨是可行的硫酸软骨素新来源。     

Kinetic study on the effects of acidic polysaccharides on the interaction of fibrinogen and thrombin

Summary Retardation effect of acidic polysaccharides on the interactions of fibrinogen with thrombin was kinetically investigated by measuring the turbidity as a measure of the concentration of fibrin polymer formed in the system. To this aim, the fibrinogenfibrin conversion curve was analyzed kinetically based on the elementary reactions, and the slope and the induction period of the conversion curve were expressed as functions of the concentrations of fibrinogen, thrombin, and polysaccharide. The strong retardation effect of dextran sulfate and heparin was quantitatively interpreted. Seven kinds of polysaccharides were examined.     

Deproteinization and structural characterization of bioactive exopolysaccharides from Ganoderma sinense mycelium

Deproteinization was comparatively employed for the purification of crude exopolysaccharide (CEP) of Ganoderma sinense mycelium. Results showed that ammonium sulfate (70% saturation) salting out could remove 95% proteins of CEP, whereas 20% trichloroacetic acid precipitation was best with a polysaccharide loss less than 20%. Protein-bound polysaccharides could be removed by both methods, and polysaccharides with high molecular weight dominated in the lost polysaccharides. Through anion-exchange chromatography, a highly branched α-(1→6)-D-mannan and a protein-bound heteropolysaccharide were prepared from CEP. Both fractions could inhibit the in vitro proliferation of tumor cells BEL-7402, and induce TNF-α secretion of murine splenocytes.     

Fabrication of poly(3,4‐ethylenedioxythiophene)‐polysaccharide composites

Poly(3,4‐ethylenedioxythiophene) (PEDOT) doped with a series of anionic polysaccharides such as carboxymethyl cellulose, sodium hyaluronate, xanthan gum, pectin, gellan gum were prepared by electropolymerization in aqueous solutions. Some other dopants of potassium nitrate, potassium sulfate, sodium poly(styrenesulfonate), and sodium polyacrylate were used in comparison with the anionic polysaccharides. The electrochemical properties and stability of the obtained PEDOT films were also investigated. It was found that indium tin oxide (ITO) conductive glass could be used as the working electrode of the electropolymerization of EDOT and that the dopant had a great influence on polymerization potential and overoxidation potential. These charged biomolecules of anionic polysaccharides were found to facilitate electropolymerization of EDOT instead of common doping anions as counterion. The electroactive PEDOT films doped with anionic polysaccharides showed stable electrochemical properties, good texture, and adhesion properties to the ITO conductive glass. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012     

生物活性多糖在化妆品中的应用

综述了生物活性多糖的护肤性能，包括延缓衰老、血管美容、抗粉刺、修复皮肤组织、美白和保湿作用。这与多糖的抗凝血、抗氧化、促进细胞增生和抑菌等生物学功能和吸水性的理化特性有关。透明质酸、甲壳素和肝素等多糖已作为功效型添加剂在化妆品行业有着广泛的应用。还介绍了一种具有抗凝血活性的新型多功能化妆品添加剂——纤维素硫酸酯，指出生物活性多糖在功效性化妆品中有着广阔的应用前景。     

Evaluation of adhesion properties of blends of cottonseed protein and anionic water-soluble polymers

There is increasing interest in agro-based, biodegradable and eco-friendly wood adhesives as partial replacements for petroleum-based adhesives. In this work, we studied the adhesion of cottonseed protein isolate (CPI) blended with several anionic water-soluble polymers. Anionic vinyl polymers studied included poly(acrylate), poly(acrylate-co-acrylamide), poly(vinyl sulfate), poly(vinyl sulfonate), and poly(vinyl phosphonate). Anionic polysaccharides studied included three types of carrageenan, carboxymethyl cellulose (CMC), low-methoxy pectin, alginate, and chondroitin sulfate. In general, the adhesive strength of CPI increased with the addition of anionic polymer up to a certain level and then decreased with further polymer addition. Different anionic polymers showed different enhancements. The best result for vinyl polymers was observed for the CPI/poly(vinyl sulfate) blend, which exhibited a 30% improved dry strength over CPI alone. The best results for the polysaccharides were obtained for the CPI/CMC and CPI/pectin blends, with improvements in dry adhesive strength over the CPI control of 66% and 50%, respectively. The CPI/CMC and CPI/pectin blends also showed improved hot water resistance. These findings suggest that the CPI/anionic polymer blends might be useful components in biobased wood adhesive formulations.     

Increased thermal stability of nanocellulose composites by functionalization of the sulfate groups on cellulose nanocrystals with azetidinium ions

Cellulose nanocrystals (CNCs) prepared via sulfuric acid hydrolysis are decorated with sulfate groups that yield a stable water suspension. To make the CNCs adaptable for use in composites, the hydroxyl groups on the surface are usually hydrophobized. In this article, an alternative hydrophobization method is described in which the sulfate groups are conjugated with azetidinium salts. The results of this study show that the sulfate groups can be functionalized with azetidinium salts and from thermal studies, it was discovered that the functionalization led to a 100 °C increase in thermal stability, compared with unmodified CNCs. The nanocomposites prepared by extrusion of CNC‐coated low‐density polyethylene powder displayed similar mechanical properties as the CNC‐reference sample, but without the discoloration, due to the increased thermal stability. In conclusion, the azetidinium reagent reacts preferentially with sulfate groups, and this new type of chemical conversion of sulfate groups on polysaccharides will be beneficial in nanocomposite manufacturing. © 2017 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2018 , 135, 45963.     

酱油曲霉产微生物絮凝剂MBFA1的纯化及成分分析

经离心、乙醇沉淀、透析、凝胶过滤层析及冷冻干燥后获得纯化的微生物絮凝剂MBFA1,并利用紫外、红外、凝胶渗透色谱、气质色谱进行絮凝剂的组分、含量、分子量和结构的分析。结果表明,纯化后的MBFA1为淡黄色,主要成分为多糖类物质,其中多糖含量为91.2%,蛋白质为0.59%。元素分析显示MBFA1中C、H、N、S的含量分别为33.41%、7.69%、9.63%和0.39%。采用凝胶色谱法测得MBFA1的重均相对分子质量约为1.38×104。紫外光谱显示,MBFA1在199 nm处出现了吸收峰值,为多糖的特征峰。红外光谱显示MBFA1中含有羟基、氨基、羧基、氢键、硫酸根等对絮凝有利的基团。GC-MS分析MBFA1主要的单糖构成为D-葡萄糖,并含有少量的D-阿拉伯糖及D-甘露糖,其摩尔比约为100.7∶1∶8.2。     

On the optical activity of pseudoisocyanine bound by sulfated polysaccharides in dilute aqueous solution

Summary Visible absorption and circular dichroism spectra of the cationic dye pseudoisocyanine bound to sulfated polysaccharides in dilute aqueous solution are reported. Characteristic, strong optical activity is associated with stacks of dye molecules bound by dextran sulfate as well as by i-carrageenan in the random coil states. Conversion of i-carrageenan chains to an ordered state (by addition of NaCl) markedly changes the dye circular dichroism spectrum. The possible configurational origins of the observed effects are pointed out.