MALDI-TOF质谱准内标法及其用于rhTPO复杂糖一致性研究

采用基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)准内标法准确测定重组人血小板生成素(rhTPO)仿制药和原研药中4类糖修饰的相对含量,并进行样本间和批间一致性比较。结合多种切糖酶逐步切除rhTPO的N-糖、唾液酸和O-糖;以牛血清白蛋白(BSA)为标准品,与样本非混合点靶;采用MALDI-TOF质谱准内标法检测,分别获得各样本完整含糖分子量及不同层次切糖后分子量;通过分子量差值计算4类糖修饰的相对含量;最后比较仿制药与原研药样本间和批间一致性。以BSA多电荷峰对rhTPO切糖前后的MALDI-TOF质谱测定值进行准内标法校正,BSA多电荷峰之间相对标准偏差(RSD)均≤0.075%,批间RSD为0.001%~0.004%,方法误差均0.01%。rhTPO仿制药N-糖、O-糖唾液酸、O-糖和糖化糖的相对含量分别约为24.6%、2.9%、9.0%和5.1%,批间一致性良好,且总糖含量与文献值一致;rhTPO原研药N-糖、O-糖唾液酸、O-糖和糖化糖的相对含量分别约为25.6%、2.9%、7.9%和3.5%,总糖含量较文献值偏低。与rhTPO原研药相比,仿制药糖基化糖相对含量基本一致,糖化糖含量有差异。rhTPO糖化糖研究未见文献报道,其差异是不同厂家rhTPO之间差异的重要因素,主要由发酵工艺差异导致。     

糖番的合成方法及应用研究进展

糖番是一类兼具环番和天然环糊精性质的化合物。本文就糖番的定义、结构、发现和命名等作一基本介绍,并综述了糖番合成的发展、不同的合成路线、合成策略和合成条件,揭示了糖番这类手性的、水溶性的、具有疏水性空腔结构特点的化合物可能在生物、医药、化工等领域具有潜在的应用价值。根据它的手性识别和糖-糖相互作用的能力,预测了这类化合物于主客体化学、寡糖的识别、催化剂设计等方面的应用。最后,根据糖番的结构特点,指出对于其糖基和芳香烃部分的结构改造,可能是未来糖番合成的发展方向,以期对以后糖番的合成提供启示和借鉴。     

在汞电极上酮糖还原的电化学行为

用极谱法及恒电位电解法研究了酮糖中的单糖、果糖、塔格糖、二糖、拉克杜糖的电还原行为，由酮糖的电还原行为从理论上导出了相应的极谱电流－电压方程，该方程被实验所证实，成功地解释了实验现象。恒电位电解后电解的分析结果表明，电解选择性为１００％，电解产物为由酮糖还原成相应的多元醇。     

糖芯片制备和应用的最新研究进展

糖芯片是一种研究微量糖与生物大分子之间相互作用的生物检测技术,因其具有用量少、快速、高效和高通量等特点,现已被广泛应用到药物开发、免疫学,临床诊断和细菌检测等诸多领域中。近年来,尽管对糖芯片的制备方法和应用进行了较为深入的研究,但对糖芯片的制备方法和应用的综述还较少报道。本文主要介绍糖芯片的制备原理、非化学修饰和化学修饰制备糖芯片的最新方法,然后对糖芯片在自组装等方面应用的最新进展进行综述,并对糖芯片所遇到的挑战和发展趋势也作了展望。     

糖芯片最新研究进展

糖芯片是一种快速、高效、高通量获取糖-生物大分子相互作用信息的生物检测技术,对后基因组时代糖生物学的发展具有重大影响。本文主要论述了糖芯片固定化技术的最新进展,包括未经化学修饰的糖的化学固定,天然糖库及其固定,复杂寡糖的合成及其固定,糖基的密度差异固定化技术以及间隔基的引入技术。这些新的固定化技术保持了糖的化学结构,扩大了糖芯片的来源和应用范围,进一步提高了糖芯片的检测效率。此外,本文还介绍了虚拟筛选技术在这一领域的应用潜力以及糖芯片在医疗诊断等方面的应用,最后对糖芯片技术遇到的挑战和发展做了展望。     

半刀豆球蛋白非标记电化学阻抗传感器

近年来,糖生物学在糖链结构、生物合成、生理功能以及疾病诊断等方面的研究备受关注.糖芯片是继基因芯片和蛋白质芯片之后兴起,正如继基因工程、蛋白质工程之后兴起的糖工程,继基因组学、蛋白质组学之后兴起的糖组学一样,功能糖芯片技术已成为第3代高通量、大规模生物芯片检测技术的核心.     

探秘无糖饮料的甜

市面上的无糖饮料日渐增多，但人们关于无糖饮料中的甜味还知之甚少。简要介绍甜味剂及其分类、无糖饮料中甜味剂的使用情况、甜味剂对人体的影响等，以期提升人们对无糖饮料中甜味剂的理解。其中对人体的影响方面主要针对无糖饮料中常用的7种甜味剂。     

气相色谱定量分析单糖的研究

单糖糖腈乙酰酯制备简单,性质稳定,是气相色谱分析葡萄糖、半乳糖、木糖、阿拉伯糖、甘露糖等醛糖的较理想衍生物。本文研究了XE-60和OS-138两种固定液对糖腈乙酰酯的分离,以求配制出适用单糖含量有数量级差别的糖样分析柱;选用4,4′-二异丙基联苯为内标,研究反应条件对糖腈乙酰酯得率的影响;测定阿拉伯糖、木糖、甘露糖、葡萄糖和半乳糖(衍生成糖腈乙酰酯)对内标的相对响应值以用于单糖的定量分析。     

糖组学研究中糖蛋白糖链结构分析技术

遗传信息由DNA传递至蛋白质,再经蛋白质翻译后糖基化修饰形成糖蛋白.与DNA、蛋白质相比,糖蛋白糖链结构更加多样,功能更加复杂,在一些重大的生理、病理事件中发挥着重要调节作用;而糖链如此复杂的功能是由其多样的结构决定的,糖链结构是糖组学研究的重要内容.本文就近年来糖组学研究中糖蛋白样品的提取分离、糖链释放及结构分析的基本方法及相关技术进展作了简要介绍.     

298.15 K下NaBr在D-海藻糖和D-纤维二糖水溶液中的活度系数

通过测定由离子选择性电极组成的电池的电动势, 分别求得了298.15 K下NaBr和二糖（D-海藻糖/D-纤维二糖）在NaBr–D-海藻糖/D-纤维二糖–水三元体系中的活度系数, 计算了NaBr和这两种二糖的相互作用参数C1. 基于糖立体结构比较讨论了NaBr与海藻糖、纤维二糖和葡萄糖相互作用的差异.     

Determination of traces of fluorine or sulfur by x-ray analysis

New X-ray methods have been developed for the determination of as little as 1 μg of fluorine or as little as 0.1 μg of sulfur. Fluorine as fluoride is precipitated as lanthanum fluoride in 75% ethanol-water mixture and determined by measuring the amount of lanthanum present in the precipitate. Sulfur as sulfate is precipitated as barium sulfate from a barium sulfate saturated 50% ethanol-buffer mixture, using selenate as a coprecipitant, and determined by measuring the amount of sulfur present. Sulfur as sulfide is precipitated as cadmium sulfide and determined by measuring the amount of sulfur or cadmium in the precipitate.     

Controlled release of volatiles under mild reaction conditions: from nature to everyday products

Volatile organic compounds serve in nature as semiochemicals for communication between species, and are often used as flavors and fragrances in our everyday life. The quite limited longevity of olfactive perception has led to the development of pro-perfumes or pro-fragrances--ideally nonvolatile and odorless fragrance precursors which release the active volatiles by bond cleavage. Only a limited amount of reaction conditions, such as hydrolysis, temperature changes, as well as the action of light, oxygen, enzymes, or microorganisms, can be used to liberate the many different chemical functionalities. This Review describes the controlled chemical release of fragrances and discusses additional challenges such as precursor stability during product storage as well as some aspects concerning toxicity and biodegradability. As the same systems can be applied in different areas of research, the scope of this Review covers fragrance delivery as well as the controlled release of volatiles in general.     

三明治式双极膜的制备及其光催化性能

以Cr3+交联羧甲基纤维素钠(CMC)作为阳膜层,戊二醛改性壳聚糖(CS)作为阴膜层,纳米TiO2光催化剂作为双极膜的中间层,在TiO2上涂布光敏剂八羟基喹啉（Oxine）以增强其光催化解离水的性能,制备了三明治式的双极膜（mCMC/TiO2-Oxine/mCS BPM)。 该双极膜在紫外光照射下,具有高的水解离效率,优良的亲水性能,双极膜阻抗小,工作电压低,当工作电流密度达0.12 A/cm2时,电槽工作电压小于5.0 V。     

咪草烟分子印迹聚合物的制备及其选择性吸附性能的研究

以丙烯酸为聚合单体,TMPTA为交联剂,AIBN为引发剂,咪草烟为模板分子,采用在低温光聚合的方法,制备了对咪草烟分子具有选择性识别能力的分子印迹聚合物．通过IR和HPLC表征,咪草烟分子印迹聚合物对咪草烟分子具有良好的识别作用．     

Macromolecular chemistry and medicine

Macromolecular substances are used in medicine both as materials and as reagents. In the former category polymers serve as replacements for soft tissue, as cardiovascular and orthopedic implants, and as adhesives. When employed as reagents, macromolecules interact with living tissue and play an active part in bodily repair processes.     

双氧水氧化环己烯催化合成己二酸研究进展

评述了近年来以环己烯为底物,双氧水为氧源,分别采用钨酸盐、钨酸、杂多酸及杂多酸盐、功能化分子筛和负载离子液体等为催化剂催化合成己二酸的研究进展.     

Oxazole and Isoxazole Chemistry in Crop Protection

An overview is given of the significance of the oxazole and isoxazole scaffolds in crop protection chemistry. The main herbicidally, fungicidally, and insecticidally active oxazole and isoxazole classes are presented, together with their synthesis routes, modes of action, and biological efficacies. In addition, the role of oxazoles and isoxazoles as lead structure or as intermediate in the synthesis of other agrochemicals is reported. Also, partially and fully saturated oxazole and isoxazole derivatives such as oxazolines, isoxazolines, oxazolidines, and isoxazolidines, oxygenated derivatives such as oxazolones and isoxazolones as well as annulated derivatives, such as benzoxazoles and benzisoxazoles, are covered.     

Chemical reaction and Soret effects on MHD convective flow of second grade fluid through an absorbent medium with ramped wall temperature as well as ramped surface concentration

In the present paper, the heat generating and/or absorption as well as thermo-diffusion on the unsteady free convection MHD gyrating flow of radiation and chemical reactive second grade fluid past an unbounded perpendicular plate during absorbent medium have been discussed. Here, it is assumed that, the confining plate has the ramped wall temperature with ramped surface concentration and isothermal temperature with ramped surface concentration. The analytical solutions for the governing equations are found by utilization of Laplace transformation methodology. The velocity, temperature and concentration profiles are analyzed with quite few figures. It is determined that, velocity, temperature and concentration distribution sketches in case of ramped temperature as well as ramped surface concentration are not as much of as those of isothermal temperature as well as ramped surface concentration. In addition to the idioms of skin friction, Nusselt number as well as Sherwood number are achieved and characterized numerically with tabular format.     

Interactions and uses of antisense peptides in affinity technology.

Antisense peptides, amino acid sequences encoded in the antisense strand of DNA, can interact with significant affinity and selectivity with their corresponding sensepeptides. Experimentally, sense-antisense peptide recognition has been observed repeatedly. However, skepticism about the biological relevance of this phenomenon has persisted. This is due in part to the unexpected and somewhat couterintutive nature of the interaction as well as to its non-universality as an empirical observation. Nonetheless, antisense peptides in several cases investigated so far have been used as immobilized ligands for the successful affinity chromatographic separation of native (sense) peptides and proteins. For example, immobilized antisense peptides corresponding to Arg8-vasopressin (AVP) have been used to separate vasopressin from oxytocin chromatographically as well as to affinity capture AVP-receptor complex. These results, together with improved understanding of the general features of amino acid sequence which drive antisense-sense peptide interactions as well as new ideas for making antisense peptides chimeras, are beginning to suggest improved ways to make antisense-related peptides as affinity agents for separation as well as for other biotechnology applications.     

Enzyme-based biocatalysis for the treatment of organic pollutants and bioenergy production

Enzyme-based biocatalysis is emerging as an advanced technique to develop green processes that help to maintain the sustainability of the environment. The bioremediation of toxic organic pollutants and waste to bioenergy production using enzymes as biocatalysts is rapidly growing due to its eco-friendly and sustainable nature. Additionally, a range of microbial species that typically grow on organic wastes can be used to produce these enzymes in an efficient manner. This is seen as a potential strategy for the development of cost-effective manufacturing for a number of biotechnological applications. The present study discusses biocatalysis as a promising and sustainable method toward the bioremediation of hazardous organic pollutants as well as for bioenergy production, based on the immense potential of enzymes as biocatalysts. Emphasis has been placed on evaluating the critical elements that can enhance the production of enzymes used as biocatalysts, as well as their functional effectiveness and stability.