细胞色素C在单糖修饰金电极上的直接电化学

Hill等发现在4,4′-联吡啶存在时,细胞色素C在金电极上能进行准可逆的电化学反应。在研究细胞色素C的直接电化学过程中,人们又发现一些生物小分子如氨基酸、嘌呤等对细胞色素C的电化学反应有促进作用,但迄今未见有关糖类分子对细胞色素C电化学反应促进作用研究的报道。本文研究了5种单糖对细胞色素C电化学反应的促进作用。     

重组人糖基化尿型纤溶酶原尿激活剂中糖链的组成研究

重组人糖基化尿型纤溶酶原激活剂(RHU-PA)是一种溶血栓药物。研究了使单糖从RHU-PA中定量释放的酸解条件和纯化单糖的方法。应用气相色谱技术测定了RHU-PA上的糖链由岩藻糖、甘露糖、半乳糖和N-乙酰氨基葡萄糖组成,相对摩尔比为1.0∶3.9∶1.1∶3.4。酸解法测得的总糖含量与酶解法测得的结果一致。     

基于对二烷基氨基苯甲酰苯胺分子内电荷转移的单糖比值法荧光受体

Two dual fluorescent receptors (1 and 2) for monosaccharides based on 4-dialky(alkyl=methyl and n-butyl) containing boronic acid group at the amido aniline were synthesized and their spectral properties were investigated. These receptors exhibited dual fluorescence with the long-wavelength band displaying strong solvent-polarity dependence, indicating the occurrence of the excited-state intramolecular charge transfer （ICT).With increasing pH value in aqueous solutions, the hybridization of the boron atom changed from sp^2 to sp^3, inducing a decrease in the total fluorescence quantum yield. The experimental results indicated that the anionic form of the boronate group acted as an electron donor and the benzanilide-like charge transfer was promoted upon hybridization change. In the presence of monosaccharides, the boronic acid in 1 and 2 changed from neutral to anionic form. The intensity of the locally excited (LE) state emission decreased in the presence of sugars while a slight increase in the intensity at the charge transfer (CT) emission occurred. Based on the change in the CT to LE intensity ratios of 1 and 2 due to sugar binding, ratiometric fluorescent assays for monosaccharide sensing were established.     

气相色谱-质谱法分析研究野生菱角壳中多糖化合物的单糖组成

采用乙醇分级沉淀法，首次从野生菱角壳中提取出4种多糖化合物，利用气相色谱-质谱法，确定了菱角多糖分别由阿拉伯糖，鼠李糖，木糖，甘露糖，半乳糖，葡萄糖，乳糖和蜜二糖组成，其中以葡萄糖，半乳糖，甘露糖和木糖为主。     

A Sensitive Derivatization Method for the Determination of the Sugar Composition after Pre-column Reductive Amination with 3-Amino-9-ethylcarbazole （AEC） by High-Performance Liquid Chromatography

3-Amino-9-ethylcarbazole （AEC） was employed for monosaccharide derivatization. The derivatives can be analyzed by high-performance liquid chromatography （HPLC） with an ultraviolet detection （wavelength： 254 nm）. Monosaccharides were quantitatively derivatized with 3-amino-9-ethylcarbazole （AEC） at 70 ℃ for 60 min. The method was linear for all samples over the concentration range tested （r〉0.999）, the precision was found to be satisfactory （R.S.D. 〈 3%）, and the recovery ratios were 〉98.62%. The stability analysis showed R.S.D. was between 1.81%-3.16%. Detection limits for the samples （D-glucose, L-xylose, D-mannose, L-arabinose, and L-rhamnose） ranged from 0.06 to 1.97 ng/mL （S/N=3）. Under the optimized derivatization and HPLC conditions, five monosaccharides were well separated using a narrow bore C18 column （250 mm×4.6 mm） with 0.1 mol/L ammonium acetate containing 25% acetonitrile at a flow rate of 0.5 mL/min. As an application, the method has been successfully applied to the determination of monosaccharide compositions of three polysaccharides SPPA-1, SPPB-1 and SPPC- 1 of Spirulina platensis. This method also has potential application to oligosaccharide or glycan analyses.     

单糖与糖胺的水相乙酰化及其气相色谱测定

1　实验部分1.1　仪器和试剂　　岛津GC 17气相色谱仪,配有氢焰检测器、HP色谱工作站。所用9种单糖和2种糖胺标准品、甲基咪唑、醋酸酐、正辛醇均为Sigma公司产品,硼氢化钠为Aldrich公司产品。1.2　单糖与糖胺的还原　　分别配制木糖(Xyl)、阿拉伯糖(Ara)、核糖(Rib)、鼠李糖(Rha)、甘露糖(Man)、半乳糖(Gal)、阿洛糖(All)、葡萄糖(Glu)、藻岩糖(Fuc)、葡萄糖胺(GluNH)、半乳糖胺(GalNH)标准溶液(100mg/L)各100mL,同时配制混合标准糖样(1g/L),加入阿洛糖为内标。将配制的标准糖液置于-20℃冰箱中保存备用,或加入5%的苯甲酸后置于-…     

温和条件下柱前标记-高效液相色谱-质谱法测定枸杞多糖中单糖组成

基于高效液相色谱-质谱联用分析技术（HPLC-MS）,在温和的NH₃·H₂O条件下,采用1-苯基-3-甲基-5-吡唑啉酮（PMP）衍生化试剂成功地标记了果糖及多种醛单糖,同时提出了PMP标记果糖的衍生化机理。采用Kromasil-C18色谱柱（100 mm×4.6 mm,3.5 μm）分离,梯度洗脱,选择离子模式检测,建立了8种常见单糖标记物的结构确认及含量测定的分析方法。该方法在一定质量浓度范围内具有良好的线性（相关系数> 0.9947）,检出限为0.003~0.05 mg/L,定量限为0.01~0.15 mg/L。平均回收率为65.1%~116.2%,相对标准偏差≤10.2%（n=5）。自制4个产地枸杞多糖,对其单糖组成的分析结果表明,它们均由甘露糖、果糖、鼠李糖、半乳糖、葡萄糖、木糖、阿拉伯糖和脱氧核糖8种单糖组成,但各种单糖含量的分布有较大的差异。该法简便,灵敏度高,重复性好,可用于水热法水解枸杞多糖水解液中单糖标记物结构的确认及测定,对规范植物多糖的质量控制具有重要意义。     

牛膝多糖中单糖组分的毛细管电泳-电化学检测方法研究

利用毛细管电泳－电化学检测技术（CE－EC）对牛膝多糖水解液中的单糖进行了分离测定,证实牛膝多糖的化学组成中主要有葡萄糖、甘露糖和果糖3种单糖组分,并对其含量进行了测定。讨论了工作电位、分离电压、缓冲液浓度等因素对分离检测的影响。     

基质辅助激光解吸电离-飞行时间质谱法检测罕见单糖合成酶

以VioF(普罗威登斯菌O30中O抗原基因簇内)编码的甲酰基转移酶酶促反应产物为研究对象,采用碰撞诱导解离(CID)负离子模式基质辅助激光解吸电离-飞行时间质谱(MALDI-TOF MS)技术建立简单、高效的罕见单糖合成酶监测方法。本方法首先直接质谱分析0.3μL未经色谱分离、除盐处理的酶促反应混合物,随后应用CID串联质谱技术对酶活反应产物进行结构表征,实现酶活反应的快速监测。结果表明:高能CID MALDI-TOF/TOF-MS平台适用于新建克隆的单糖合成酶酶活反应的监测,与现有的监测方法相比,在速度、灵敏度、重现性、自动化和溶剂消耗方面具有绝对优势。