基于柱前衍生-HPLC法研究焦栀子炮制过程单糖组成及含量变化

目的 建立柱前衍生-HPLC法测定焦栀子炮制过程样品中8种单糖（甘露糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、葡萄糖、半乳糖、木糖、阿拉伯糖）的含量测定方法,通过分析比较总单糖、结合型单糖和游离单糖的组成及差异,为揭示焦栀子炒制过程颜色褐变机制奠定基础。方法 以Phenomenex Luna C18柱（250 mm×4.6 mm,5μm）为色谱柱,流动相为100 mmol/L乙酸铵-乙腈（83∶17）,柱温35℃,体积流量1.0 mL/min的条件下,分别对酸水解糖提取方法、游离糖提取条件进行优化,衍生化后样品进行方法学考察。结果 酸水解方法以1.5 mol/L硫酸、100℃水解4.0 h最佳,游离单糖为超声处理15 min。焦栀子炮制过程样品酸水解产物检测出甘露糖、鼠李糖、葡萄糖醛酸、半乳糖醛酸、葡萄糖、半乳糖、木糖、阿拉伯糖共8种单糖;游离单糖检测出甘露糖、葡萄糖和半乳糖。经方法学验证,8种单糖的精密度、重复性、稳定性、加样回收率均符合方法学要求;酸水解得到的总单糖在种类上、含量上均高于游离单糖,总单糖和结合型单糖部分糖变化基本一致,甘露糖含量呈先降后升的趋势,半乳糖醛酸含量呈降低趋势,...     

Hyperosmotic arabinose solutions open the tight junctions between brain capillary endothelial cells in tissue culture

Noradrenergic, serotoninergic and peptidergic nerves have been demonstrated in perivascular plexuses of vasa nervorum of sympathetic, parasympathetic and somatic nerve trunks. 5-Hydroxytryptamine-, vasoactive intestinal polypeptide- and substance P-containing fibers were found by immunohistochemistry to variable extents in whole mounts of the epineurium of sciatic, vagus and paravertebral sympathetic chains of rabbits. Innervation increased with age. This suggests an hitherto unsuspected role for these vasoactive substances in normal blood flow to nerves and in the genesis of experimental and human neuropathies.     

自杀质粒同源重组方法构建弗氏志贺菌htrA可控表达菌株

目的：构建弗氏志贺菌HtrA蛋白的可控表达菌株。方法构建自杀质粒同源重组载体,利用重组方法在基因组htrA前插入阿拉伯糖启动子,同时构建并导入外源表达AraC蛋白的表达载体,实现对HtrA蛋白的可控表达;在此基础上,通过蛋白印迹实验,检测诱导前后全菌以及周质中HtrA蛋白的表达情况。结果测序结果表明,自杀质粒同源重组载体以及外源表达载体构建成功;蛋白印迹实验结果显示,对比阿拉伯糖诱导菌株,未诱导菌株中基本未检测到HtrA蛋白的表达。结论自杀质粒同源重组方式可在无阿拉伯糖时有效阻遏HtrA蛋白的表达;同时在诱导后,还可恢复HtrA蛋白的正常表达,有利于后续功能研究。     

Chemical and biological characterization of polysaccharides from wild and cultivated roots of Vernonia kotschyana

Ethnopharmacological relevance

In Malian traditional medicine the roots of Vernonia kotschyana are used for treating gastric ulcer and gastritis. In 2006, 9000 kg of roots from Vernonia kotschyana were used to produce Gastrosedal, an ameliorated traditional medicine in Mali. Harvesting from the wild, the main source of raw material, is causing a growing concern of diminishing populations of the plant, and Vernonia kotschyana is now being cultivated in several areas around Mali. In the current study the structures and bioactive properties of isolated polysaccharides from wild and cultivated Vernonia kotschyana were compared.

Materials and methods

Pectin- and inulin-type polysaccharides were isolated from the roots of cultivated and wild Vernonia kotschyana. The isolated polysaccharides were investigated regarding their chemical compositions, and for their abilities to fixate human complement and activate macrophages from a mouse macrophage cell line.

Results

No significant differences in the carbohydrate composition of the fractions isolated from the cultivated versus the wild roots were observed. A previously reported pectic arabinogalactan Vk2a was found in both the cultivated and the wild roots in this study, and exhibited potent complement fixation activity, and a moderate activation of macrophages.

Conclusions

The present study has shown that the cultivated roots of Vernonia kotschyana contain the same types of bioactive polysaccharides as the wild roots. It is therefore preliminarily feasible for the cultivated roots of Vernonia kotschyana to be used as a herbal medicine to replace the wild roots.     

Computational design of ligand binding is not a solved problem

Computational design has been very successful in recent years: multiple novel ligand binding proteins as well as enzymes have been reported. We wanted to know in molecular detail how precise the predictions of the interactions of protein and ligands are. Therefore, we performed a structural analysis of a number of published receptors designed onto the periplasmic binding protein scaffold that were reported to bind to the new ligands with nano- to micromolar affinities. It turned out that most of these designed proteins are not suitable for structural studies due to instability and aggregation. However, we were able to solve the crystal structure of an arabinose binding protein designed to bind serotonin to 2.2 Å resolution. While crystallized in the presence of an excess of serotonin, the protein is in an open conformation with no serotonin bound, although the side-chain conformations in the empty binding pocket are very similar to the conformations predicted. During subsequent characterization using isothermal titration calorimetry, CD, and NMR spectroscopy, no indication of binding could be detected for any of the tested designed receptors, whereas wild-type proteins bound their ligands as expected. We conclude that although the computational prediction of side-chain conformations appears to be working, it does not necessarily confer binding as expected. Hence, the computational design of ligand binding is not a solved problem and needs to be revisited.     

HPLC-DAD-MS(n) analysis and HPLC quantitation of chemical constituents in Xian-ling-gu-bao capsules

In this study, a systematic method was established for the global quality control of Xian-ling-gu-bao capsules (XLGB), a popular six-herb Traditional Chinese Patent Medicine (TCPM) for the treatment of osteoporosis. Both qualitative and quantitative analyses were conducted. In qualitative analysis part, a fast and sensitive method based on high-performance liquid chromatography coupled with diode-array detection and electrospray ionization tandem mass spectrometry (HPLC-DAD-MS(n)) was established for rapid separation and sensitive identification. Samples were separated on a Waters Symmetry C(18) column (250mm×4.6mm, 5μm) by gradient elution using acetonitrile (A) and water-formic acid (B; 0.03%, v/v) as mobile phase at a flow rate of 1.0ml/min. Based on the mass spectra, UV spectra and retention time, 47 compounds were identified or tentatively characterized, including 27 flavonols (all from Epimedii Herba, the major component herb), 4 coumarins, 3 flavonones, 1 chalcone, 3 isoflavones, 1 coumestrol, 3 triterpenoid saponins, 1 iridoid, 3 steroidal saponins, and 1 phenolic acid. Among them, 18 compounds were confirmed by comparing with reference standards. In quantitative analysis part, 10 major compounds in 18 batches of XLGB were simultaneously determined by HPLC/UV detected at 270nm. The method was validated with respect to intra- and inter-day precision, repeatability and stability, with RSD less than 1.0%, 1.5%, 2.9% and 1.8%, respectively. All the 10 analytes showed good linearity in wide linear ranges (r(2)=0.9999), and their average recoveries varied between 97.8% and 104.9%.     

Complement activity of polysaccharides from three different plant parts of Terminalia macroptera extracted as healers do

Ethnopharmacological relevance

Water decoctions of the root bark, stem bark and leaves of Terminalia macroptera are used by traditional healers in Mali to cure a wide range of illnesses, such as wounds, hepatitis, malaria, fever, cough and diarrhea as well as tuberculosis. Plant polysaccharides isolated from crude water extracts have previously shown effects related to the immune system. The aims of this study are comparing the properties of the polysaccharides among different plant parts, as well as relationship between chemical characteristics and complement fixation activities when the plant material has been extracted as the traditional healers do, with boiling water directly.

Materials and methods

Root bark, stem bark and leaves of Terminalia macroptera were extracted by boiling water, and five purified polysaccharide fractions were obtained by anion exchange chromatography and gel filtration. Chemical compositions were determined by GC of the TMS derivatives of the methyl-glycosides and the linkage determined after permethylation and GC–MS of the derived partly methylated alditol acetates. The bioactivity was determined by the complement fixation assay of the crude extracts and purified fractions.

Results

The acidic fraction TRBD-I-I isolated from the root bark was the most active of the fractions isolated. Structural studies showed that all purified fractions are of pectic nature, containing rhamnogalacturonan type I backbone. Arabinogalactan type II side chains were present in all fractions except TRBD-I-II. The observed differences in complement fixation activities among the five purified polysaccharide fractions are probably due to differences in monosaccharide compositions, linkage types and molecular sizes.

Conclusion

The crude extracts from root bark and stem bark have similar total activities, both higher than those from leaves. The root bark, leaves and stem bark are all good sources for fractions containing bioactive polysaccharides. But due to sustainability, it is prefer to use leaves rather than the other two plant parts, and then the dosage by weight must be higher when using leaves.     

整合糖组与代谢组学方法比较蒸制和酒炖熟地黄化学成分

目的对《中国药典》收载的蒸制和酒炖2种炮制法所得熟地黄的化学成分进行比较研究。方法整合基于HPLC(C₁₈)-PDA、HPLC(NH₂)-ELSD和高效凝胶渗透色谱(HPGPC)-ELSD的糖组学和基于UPLC-QTOF-MS/MS的代谢组学方法,对2种熟地黄的糖类组分(多糖、寡糖和游离单糖)和非糖小分子组分进行分析比较。结果与蒸制地黄相比,酒炖地黄多糖相对分子质量范围更宽,较大相对分子质量多糖占比较高。2种熟地黄多糖均由甘露糖、半乳糖醛酸、葡萄糖、半乳糖和阿拉伯糖组成,但其物质的量比稍有不同(2.57∶0.05∶1.00∶0.87∶0.10vs2.07∶0.07∶1.00∶1.05∶0.17)。2种熟地黄均含有寡糖水苏糖、甘露三糖和蜜二糖,但酒炖地黄中水苏糖含量显著高于蒸制地黄(P<0.01)。2种熟地黄均含有游离单糖葡萄糖、果糖、鼠李糖、甘露糖、半乳糖和阿拉伯糖,但酒炖地黄中葡萄糖(P<0.01)、鼠李糖(P<0.05)和甘露糖(P<0.05)含量均显著低于蒸制地黄,而半乳糖含量显著高于蒸制地黄(P<0.05...     

趁鲜切制和传统切制金荞麦饮片糖类组分比较研究

目的 比较趁鲜切制和传统切制方法对金荞麦Fagopyri Dibotryis Rhizoma饮片糖类组分的影响,基于糖组分探究适宜的金荞麦饮片切制方法。方法 采用多维色谱技术表征2种饮片中多糖含量、相对分子质量分布、单糖组成及物质的量比以及寡糖和游离单糖的含量,结合统计分析,比较2种饮片的糖组分特征。结果 与传统切制法相比,趁鲜切制饮片中多糖、寡糖含量较高;2种饮片中多糖的相对分子质量分布范围相似,但传统方法切制饮片在4.456×10⁶～8.095×10⁶区域占比较高;2种饮片多糖都主要由D-甘露糖、D-半乳糖醛酸、D-葡萄糖、半乳糖和阿拉伯糖组成,但传统方法切制饮片的D-葡萄糖物质的量比较高,D-甘露糖、半乳糖和阿拉伯糖物质的量比较低。结论 趁鲜切制能更好地保留多糖和寡糖组分,且操作方法相对简便,可以考虑作为金荞麦饮片的候选切制方法。     

基于代谢组学分析不同蒸制次数熟地黄中糖类成分的变化规律

目的:基于代谢组学技术研究不同蒸制次数的熟地黄中糖类成分的变化规律。方法:收集采用传统方法加工的第1蒸至第9蒸熟地黄样品,分别对其水提液进行1-苯基-3-甲基-5-吡唑啉酮衍生及LC-MS测定。采用SIMCA-P 13.0软件进行主成分分析(PCA)和正交偏最小二乘法-判别分析(OPLS-DA),得到差异标记物,通过多级质谱离子碎片及对照品比较对差异标记物进行鉴定。结果:经OPLS-DA共鉴定了6种糖类化合物,分别为甘露三糖、蜜二糖、甘露糖、葡萄糖、半乳糖和阿拉伯糖;其中甘露三糖和蜜二糖逐渐降低,在第9蒸熟地黄中相对峰面积最低,分别为0.60和0.52;阿拉伯糖逐渐升高,在第9蒸熟地黄中相对峰面积达到4.74;甘露糖先升高后降低,其相对峰面积在第5蒸熟地黄中最高,达3.33;而葡萄糖和半乳糖基本上处于稳定状态。PCA结果显示第1蒸至第9蒸熟地黄沿着PC1轴逐渐改变,糖类代谢物发生着显著变化。结论:不同蒸制次数的熟地黄样品中糖类成分差异较大,可为九蒸九晒熟地黄的质量评价提供实验依据。