人参总糖的近红外光谱定量分析

采用近红外光谱分析技术对中国人参的总糖指标进行了光谱及定量分析,并且结合偏最小二乘回归法对人参总糖进行了定标建模分析,分析结果表明该技术所给出的分析精度可以和传统化学分析方法相媲美,定标标准差(RMSEC)为1.9％,相关系数为0.951 7,而且具有分析速度快、无化学污染、样品制备简单、分析成本较低、适用于在线成分质量监控等特点。     

Utility of Bioluminescent Homogeneous Nucleotide Detection Assays in Measuring Activities of Nucleotide-Sugar Dependent Glycosyltransferases and Studying Their Inhibitors

Traditional glycosyltransferase (GT) activity assays are not easily configured for rapid detection nor for high throughput screening because they rely on radioactive product isolation, the use of heterogeneous immunoassays or mass spectrometry. In a typical glycosyltransferase biochemical reaction, two products are generated, a glycosylated product and a nucleotide released from the sugar donor substrate. Therefore, an assay that detects the nucleotide could be universal to monitor the activity of diverse glycosyltransferases in vitro. Here we describe three homogeneous and bioluminescent glycosyltransferase activity assays based on UDP, GDP, CMP, and UMP detection. Each of these assays are performed in a one-step detection that relies on converting the nucleotide product to ATP, then to bioluminescence using firefly luciferase. These assays are highly sensitive, robust and resistant to chemical interference. Various applications of these assays are presented, including studies on the specificity of sugar transfer by diverse GTs and the characterization of acceptor substrate-dependent and independent nucleotide-sugar hydrolysis. Furthermore, their utility in screening for specific GT inhibitors and the study of their mode of action are described. We believe that the broad utility of these nucleotide assays will enable the investigation of a large number of GTs and may have a significant impact on diverse areas of Glycobiology research.     

酶促反应合成糖脂化合物

对糖脂化合物的酶促合成研究进行了总结,其中包括有机相中和无溶剂条件下的糖脂酶促合成。     

糖和糖醇的高效液相色谱分析

采用高效液相色谱示差折光检测器（ＲＩ）,对９种糖和五种糖醇进行了分离检测;另以对甲氧基苯胺和苯甲酰氯为衍生试剂,分别对糖和糖醇进行柱前衍生,使其接上紫外吸收基团,然后用紫外检测器（ＵＶ）进行检测。在０．５￣１２ｇ／Ｌ浓度范围内,对糖和糖醇浓度与其衍生物峰面积进行线性回归分析,其相关系数在０．９８４￣０．９９８之间;ＵＶ的检测灵敏度比ＲＩ的要高约１０００倍。     

川续断中新七糖三萜皂苷的核磁共振研究

从中药川续断根部的乙醇提取物中分得一个新的三萜皂甙.经过测定,它为:3-O[α-L-吡喃鼠李糖(1→3)][-β-D吡喃葡萄糖(1→4)]-β-D吡喃葡萄糖(1→3)-α-L-吡喃鼠李糖(1→2)-β-L-吡喃阿拉伯糖-常春藤甙元-28-O-β-D-吡喃葡萄糖(1→6)-β-D-吡喃葡萄糖酯甙.本文采用一维SEMDY,旋转坐标NOE差谱和选择性远程DEPT新技术相结合测定该化合物的糖链结构.     

Crystal Structure and Conformation of an Imino Sugar

The title compound 3 was synthesized and characterized by IR,NMR and H-RMS,and its crystal structure was determined by X-ray diffraction analysis. The crystal is of monoclinic system (C16H23NO7S,Mr=373.41),space group P21,with a=12.000(2),b=5.5970(11),c=13.689(3),β=93.25(3)°,V=917.9(3)3,Z=2,Dc=1.351 g/cm3,F(000)=396,μ=0.213 mm-1,the final R=0.0489 and wR=0.0777 for observed reflections (I > 2σ(I)). Three intramolecular and three intermolecular hydrogen bonds were found. The absolute configuration of this molecule was confirmed by comparing with the original material.     

FT-NIR光谱仪测定烟草化学成分不同谱区范围对数学模型影响的研究

应用傅里叶近红外技术建立快速定量分析烟草化学成分的数学模型 ,使用BrukerOptics公司的MPA型傅里叶变换近红外光谱仪 ,谱区扫描范围 12 0 0 0～ 4 0 0 0cm- 1 ,选择不同的谱区范围对烟碱、总糖和总氮三种组分的数学模型进行优化 ,结果显示不同谱区范围对同一组分数学模型影响有明显的差异 ,而且不同组分所选择的最佳建模谱区范围是不一样的 ,说明在模型优化过程中选择最佳谱区范围是非常关键的 ,烟碱、总糖和总氮三种组分模型的最佳谱区范围分别是 95 0 0～ 4 2 31 2cm- 1 ,75 0 2 1～ 4 2 4 6 7cm- 1 ,75 0 2 1～4 5 97 7cm- 1 ,三种组分最佳模型交叉检验的均方差 (RMSECV)分别为 0 0 815 ,0 80 8,0 0 5 6。     

沉积物中多糖的微波消解及气相色谱分析

建立了采用硫酸体系微波消解沉积物中多糖,乙酰化后用气相色谱同时分离测定7种单糖的分析方法。考察了温度和微波消解时间对多糖水解效率的影响,实验表明在100℃下消解60min达到最高效率。将水解得到的单糖还原并乙酰化,采用HP-5石英毛细管柱(30m×0.32mm,0.25μm)为色谱柱,利用气相色谱法对7种单糖进行分离测定,总分析时间32min。用保留时间定性,内标法(以各个单糖的标样峰面积/内标样峰面积)进行定量。加样回收率为63%～106%,重现性测定平均相对标准偏差(RSD)为6.7%。实验结果表明本法是一种快速、有效测定沉积物中糖类物质组成的方法。     

Enhanced sugar-binding ability of deprotonated calix[4]resorcarene in water: Balance of CH-π interaction and hydrophobic effect

The complexation of calix[4]resorcarene as host and sugar (fucose) as guest in water can be significantly facilitated upon deprotonation of the OH groups of the host. The enhanced sugar-binding ability of the resulting anionic host having a more electron-rich and less hydrophobic aromatic cavity seems to result from a better sugar-host CH-π interaction.