苯酚-硫酸法测定灵芝多糖含量的研究

以灵芝子实体为样品,对利用苯酚-硫酸法测定灵芝多糖含量时的多糖提取和测定条件进行了较为详细、系统的研究,最终找到了一个多糖提取和测定的最佳条件,即用5%苯酚溶液1.0mL,硫酸5.0mL,于室温下放置30min,在490nm波长处测定吸收度.以此作为灵芝多糖含量的测定方法,结果更加准确和稳定.利用本实验的提取工艺,多糖含量超过60%.     

硫酸多糖的结构与生物活性关系研究现状

综述了国内外关于硫酸多糖结构与活性关系的研究进展。研究表明，影响硫酸多糖活性的最主要是硫酸根的取代量和取代位置；多糖的分子量、单糖种类、糖苷键的类型以及其他离子的取代，也在一定程度上影响多糖活性。     

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。     

萘酚-硫酸显色光度法测定白果多糖含量方法的研究

建立了一种以葡萄糖为标准对照品,通过α-萘酚-硫酸显色、吸光光度法测定多糖含量的方法,用于测定银杏白果多糖的含量。结果显示,溶液最大吸收波长569 nm,在0.57~11.5μg/mL范围内吸光度与被测量之间具有良好的线性关系,回归方程为C(μg/mL)=14.48A-0.120 8,R=0.999 0,RSD=2.94%,平均加样回收率96.9%;以葡萄糖计,白果中多糖的含量为7.60 g/100 g。与常用的苯酚-硫酸法相比较,测定结果和实验步骤基本一致,但萘酚-硫酸法在试剂消耗等方面更具优势。     

苯酚-硫酸法测定黄精多糖含量研究

目的:建立用苯酚-硫酸法测定黄精总多糖含量的方法。方法:以葡萄糖为对照品,在490 nm处以浓硫酸的用量、反应温度和反应时间为考察因素,优选最佳显色条件。结果:苯酚-硫酸法测定多糖的最佳显色条件为加浓硫酸7.0 mL、反应温度50℃和反应时间20 min,葡萄糖浓度在12.16~60.80 g·mL-1范围内与吸光度呈良好的线性关系(r=0.9994)。结论:用该法测定黄精总多糖含量,快速准确,稳定可靠,可作为黄精总多糖含量测定方法。     

实验教学中苯酚硫酸法检测灵芝多糖的探索

多糖提取实验是生物工程实验教学中重要内容,其分析检测是该实验的主要部分。利用苯酚-硫酸法对灵芝多糖进行检测是教科书中常用方法之一。本研究用酶标仪替代传统的分光光度仪检测多糖,优化了苯酚-硫酸法检测多糖的相关参数(试剂比例、温度、时间等),评价了用酶标仪分析灵芝多糖的方法。在实验教学实践中使用酶标仪能节约实验时间、节省危化品试剂、减少废弃物。     

硫酸酯化香菇多糖衍生物制备的研究

从香菇子实体中提取得到一种多糖化合物--香菇多糖,用不同的硫酸化试剂合成香菇多糖硫酸酯.找到合适的多糖硫酸酯化方法,研究了氯磺酸-吡啶法中不同因素对硫酸基含量及产物收率的影响.当氯磺酸与吡啶比例为1∶(2～4)、反应时间为2～4 h、反应温度为30～60℃时,可以得到较理想的香菇多糖硫酸酯.     

苯酚——硫酸法测定白及多糖

本文讨论了苯酚－硫酸法中各条件对白及多糖测定的影响,通过试验证明了此法适于白及多糖的测定。     

蒽酮-硫酸法测定地笋多糖含量的研究

采用蒽酮-硫酸法测定地笋多糖含量并对其测定条件进行研究。实验结果表明:使用蒽酮-硫酸试剂在430~800nm扫描地笋多糖的最大吸收波长为625nm,蒽酮试剂的最佳浓度为4g/L,最佳加热时间为8min,最佳显色时间4min,精密度实验RSD值为2.31%。平均回收率为92.99%,RSD为3.60%。     

海带中硫酸酯化多糖提取研究

硫酸酯化多糖 (sulfatedpolysaccharides,SPS)具有多种生物活性 ,采用了单因素分析法对硫酸酯化多糖的提取工艺条件进行了优选研究。确定了最佳条件为 :提取时间为 2h ,提取为温度 90℃ ,加水量为干净海藻质量的 2 5倍。SPS产率达到 1.99%,其主要理化指标“硫酸根 +多糖”质量分数为 61.2 6%。     

硫酸酯化多糖提取工艺优化

对硫酸酯化多糖的提取工艺条件进行了优选研究并对产品进行了鉴别实验.确定了提取时间为2 h、提取温度90℃、加水量为干净海藻的25倍的最佳条件,产率达到1.99%,主要理化指标"硫酸根 多糖"含量为61.26%.     

Derivatized Polysaccharides: Preparation,Characterization, and Application as Bioadhesive Polymer for Drug Delivery

Derivatization of a natural polysaccharide, tamarind seed polysaccharide (TSP), was carried out. Both cationic and anionic derivatives of TSP were prepared, characterized, and their degree of substitution was determined. Films prepared using derivatives were evaluated for their swelling potential and bioadhesive strength. The carboxymethyl and sulfate derivatives were showed higher swelling index and required higher force of detachment compared to native gum thus, indicating that introduction of carboxymethyl, sulfate, and amine groups in TSP can increase the bioadhesive strength. The results suggested that anionic and cationic derivatives can be employed for formulation of bioadhesive drug delivery systems.     

Freshwater Plants Synthesize Sulfated Polysaccharides: Heterogalactans from Water Hyacinth (Eicchornia crassipes)

Sulfated polysaccharides (SP) are found mainly in seaweeds and animals. To date, they have only been found in six plants and all inhabit saline environments. Furthermore, there are no reports of SP in freshwater or terrestrial plants. As such, this study investigated the presence of SP in freshwaters Eichhornia crassipes, Egeria densa, Egeria naja, Cabomba caroliniana, Hydrocotyle bonariensis and Nymphaea ampla. Chemical analysis identified sulfate in N. ampla, H. bonariensis and, more specifically, E. crassipes. In addition, chemical analysis, FT-IR spectroscopy, histological analysis, scanning electron microscopy (SEM) and energy-dispersive X-ray analysis (EDXA), as well as agarose gel electrophoresis detected SP in all parts of E. crassipes, primarily in the root (epidermis and vascular bundle). Galactose, glucose and arabinose are the main monosaccharides found in the sulfated polysaccharides from E. crassipes. In activated partial thromboplastin time (APTT) test, to evaluate the intrinsic coagulation pathway, SP from the root and rhizome prolonged the coagulation time to double the baseline value, with 0.1 mg/mL and 0.15 mg/mL, respectively. However, SP from the leaf and petiole showed no anticoagulant activity. Eichornia SP demonstrated promising anticoagulant potential and have been selected for further studies on bioguided fractionation; isolation and characterization of pure polysaccharides from this species. Additionally in vivo experiments are needed and are already underway.     

A Convenient Preparation Method for Synthesizing Formamidine Utilizing Sulfated Zirconia

Sulfated zirconia is able to effectively catalyze the reaction between aniline and trimethyl orthoformate to produce formamidine with a product yield of 97% at 313 K. N-phenylformimidate is proposed as the reaction intermediate, which reacts further with aniline to produce formamidine. Less degree of acid sites poisoning by the reaction mixture due to the weaker acidity of sulfated zirconia as well as its mesoporosity seem to play important role in this catalyzed reaction.     

Molecular Basis of the Receptor Interactions of Polysialic Acid (polySia), polySia Mimetics,and Sulfated Polysaccharides

Polysialic acid (polySia) and polySia glycomimetic molecules support nerve cell regeneration, differentiation, and neuronal plasticity. With a combination of biophysical and biochemical methods, as well as data mining and molecular modeling techniques, it is possible to correlate specific ligand–receptor interactions with biochemical processes and in vivo studies that focus on the potential therapeutic impact of polySia, polySia glycomimetics, and sulfated polysaccharides in neuronal diseases. With this strategy, the receptor interactions of polySia and polySia mimetics can be understood on a submolecular level. As the HNK‐1 glycan also enhances neuronal functions, we tested whether similar sulfated oligo‐ and polysaccharides from seaweed could be suitable, in addition to polySia, for finding potential new routes into patient care focusing on an improved cure for various neuronal diseases. The knowledge obtained here on the structural interplay between polySia or sulfated polysaccharides and their receptors can be exploited to develop new drugs and application routes for the treatment of neurological diseases and dysfunctions.     

介孔SO_4~(2-)/ZrO_2的制备、表征及性能

以正丙醇锆为锆前躯体,硫酸铵为硫源,十六烷基三甲基溴化铵(CTAB)为模板剂,溴化钾为添加剂,按n(Zr4+)∶n(CTAB)∶n(SO24-)=2∶1∶2,在水热条件、酸性介质中合成了介孔ZrO2/SO24-。通过X射线衍射(XRD),N2物理吸附,扫描电镜(SEM),FTIR分析手段对其结构进行了表征;并以乙酸正丁酯的酯化反应为探针反应,考察了其催化活性。结果表明,采用两步焙烧法去除模板剂后,该样品的介孔结构类似于MCM-41,d值为3.85nm;在500℃焙烧后,该样品仍具有274m2/g的比表面积及3.2nm的平均孔径;SEM显示焙烧后的样品形貌为球形颗粒;FTIR分析得出,焙烧产物ZrO2/SO42-中S=O键对Zr4+有强的吸电子作用,产生强的Lewis酸中心。当催化剂用量为正丁醇质量的2.5%,n(乙酸)∶n(正丁醇)=1∶2,反应3h后,乙酸的转化率达91.48%。     

The Locus of Sulfate Sites on Sulfated Zirconia

The surface of sulfated zirconia was probed using X-ray photoelectron spectroscopy. It was observed that the entire inventory of sulfur could be completely removed by sputtering the surface using an argon beam. Calibration using a TiO₂(110) standard resulted in a surface concentration of 2.85 sulfur atoms/nm². This is in reasonable agreement with a value of 4.15 sulfur atoms/nm² based on sulfur analysis on the assumption that all of the sulfur was located at the surface. These results suggest that most, if not all, of the sulfur is near or at the surface. When charging was taken into account, we observed that the oxidation state of sulfur did not change following catalyst deactivation during the isomerization of n-butane. We also determined that the entire inventory of sulfur was present as SO₄ ^2-. These results reinforce previous studies suggesting that catalyst deactivation occurs as the result of carbon deposition and not a change in the oxidation state of sulfur.     

In Vitro Antioxidant Activities of Sulfated Derivatives of Polysaccharides Extracted from Auricularia auricular

In this research, two types of sulfated polysaccharide derivatives were successfully synthesized. Their antioxidant activities were investigated by employing various established in vitro systems. In addition, the degree of sulfation was evaluated using ion-chromatography and IR spectra. The results verify that, when employing scavenging superoxide radical tests, both the sulfation of acid Auricularia auricular polysaccharides (SAAAP) and the sulfation of neutral Auricularia auricular polysaccharides (SNAAP) derivatives possessed considerable antioxidant activity and had a more powerful antioxidant competence than that of the native non-sulfated polysaccharides (AAAP and NAAP). On the other hand, AAAP and NAAP exhibited stronger activity on scavenging both the hydroxyl radical and lipid peroxidation. Available data obtained with in vitro measurements indicates that the sulfated groups of AAAP and NAAP played an important role on antioxidant activity. In sum, the research demonstrates that the antioxidant activity of sulfated polysaccharide derivatives in vitro has a potential significance for seeking new natural antioxidant protective agents.     

C36二聚脂肪酸聚乙二醇聚酯硫酸酯盐的制备及性能表征

以C36二聚脂肪酸(简称二聚酸)和聚乙二醇为原料,缩聚后得到聚酯,再用氨基磺酸硫酸化,制备了新型的C36二聚脂肪酸聚乙二醇聚酯硫酸酯盐型两性高分子表面活性剂,并对其性能进行了研究。聚酯适宜的制备工艺条件是:在0.097 MPa下,n(二聚酸)∶n(聚乙二醇)=1∶1.2,催化剂w(SnC l2)=0.3%(相对于反应物总质量),反应温度200℃,反应时间6 h,酯化率达到98.11%。聚酯平均相对分子质量为613 5,相对分子质量分布系数为1.212。优化的C36二聚脂肪酸聚乙二醇聚酯硫酸酯盐的制备条件是:尿素为催化剂,n(二聚酸聚乙二醇聚酯)∶n(NH2SO3H)∶n(尿素)=1∶1.2∶1.2,反应温度130℃,反应时间2.8 h,聚酯端羟基硫酸酯酯化率达81.17%。表面性能分析结果为:产物γCMC(25℃)为3.021 mN/m,与十二烷基硫酸钠(K12)相当;CMC(25℃)为1.07 mmol/L,远低于K12;乳化性能和乳化稳定性与壬基酚聚氧乙烯醚(OP-10)相当。与K12相比,产物起泡性差但表现出很好的抑泡性能。该工作的新颖性已为河南省科学技术情报研究所2005年12月15日出具的第2005 c0006号《论文查新报告》所证实。