A Practical and Eco-Friendly Method for Conversion of Epoxides to Thiiranes with Immobilized Thiourea on CaCO3

Abstract

Solvent-free conversion of various epoxides to the corresponding thiiranes was carried out efficiently with immobilized thiourea on CaCO₃. The reactions were completed within 1–12 min under oil bath (60 °C–70 °C) conditions to afford thiiranes in 88%–98% yields.

[Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental resource: Figures S1–S3.]

GRAPHICAL ABSTRACT      

壳聚糖-硅基凝胶微球作为固定化金属螯合亲和色谱基质的研究

采用溶胶凝胶及微乳液技术制备了以壳聚糖-硅基杂化材料为骨架并带有金属离子螯合官能团的球形基质(CSHB),并对该基质的制备条件及结构形貌进行了研究与表征。实验表明,当微乳液反应体系的组分为:100mL壳聚糖溶液(2%m/V)、100mL Span乳化剂、250mL环己烷、13.3mL四乙氧基硅烷(TEOS)、1.33mL 3-缩水甘油丙氧基三甲氧基硅烷(GPTMS)和亚氨基二乙酸(IDA)0.802g时,可获得粒径均匀,刚性较好的微球。红外光谱证明了该基质是一种多组分的杂合材料,差热分析数据表明该杂合材料的热稳定性随反应体系中GPTMS的含量增加而增大。CSHB通过动态吸附金属离子Cu2 与Ni2 后,可对金属螯合蛋白产生配位吸附作用。Cu2 -CSHB柱对牛血清蛋白(BSA)具良好的可逆吸附能力,蛋白能被咪唑等金属离子螯合剂洗脱,回收率达76.6%。BSA在CSHB柱上的吸附率只有4.7%,表明CSHB对蛋白的非特异吸附较低。Ni2 -CSHB柱对过氧化氢酶(CAT)也显示出初步的纯化效果,一步纯化倍数为2.43倍。该基质有望用于具有组氨酸纯化标签的基因工程表达蛋白的分离与纯化。     

First Stage of the Development of an Eco-Friendly Detergent Formulation for Efficient Removal of Carbonized Soil

Detergent formulations for cleaning a carbonized soil—degreasers—typically comprise surfactants, organic solvents, phosphate-based cleaning agents, and alkaline agents, which results in high pH values (>11) that raise human and environmental risks. It is important to develop eco-friendly and safer degreasers, while maintaining their cleaning efficiency. In this work, simple degreaser formulations, with a pH below 11 and without phosphates, were developed by using a mixture of solvent, surfactant, and water to remove carbonized soil. The efficiency of the new degreaser formulations (with 5 wt% solvent, 5 wt% nonionic or ionic surfactant, and 90 wt% water) was evaluated by an abrasion test in the removal of carbonized soil from ceramic and stainless steel surfaces and compared with a commercial product. The results obtained show that the formulations comprising isopropylene glycol (IPG) with C₁₁–C₁₃ 9EOs and diethylene glycol butyl ether (BDG) with octyltrimethylammonium octanoate ([N₁₁₁₈][C₈O₂]) present the best cleaning efficiency for both surfaces. The composition of these formulations was optimized for each surface using a mixture design. The resulting formulations, despite having a simpler composition, a pH lower than 11, and being phosphate-free, presented a cleaning efficiency equal or slightly higher than the commercial control. These results show that it is possible to design degreasers that are much less aggressive to the environment and user, while simultaneously fulfilling the market requirements.     

A Novel MALDI Matrix for Analyzing Peptides and Proteins: Paraffin Wax Immobilized Matrix

制作出一种新型的石蜡固化基质,并将其用于多肽以及蛋白质的MALDI-FTMS分析。在其制作过程中通过加热将固体石蜡融化并均匀涂敷在不锈钢靶板上,在不同温度下滴加基质溶液于石蜡涂层及不锈钢靶板上,分别制得不同形式的基质点。三维视频显微镜表征各基质点的表观形貌,并对比其上样前后的形貌变化。通过在不同基质点上分析多肽混合液以及牛血清白蛋白酶解液,以评价该固化基质的性能。MALDI-FTMS分析结果表明石蜡涂层内固化基质方法检测灵敏度明显优于其它几种状况下的样品分析方法。     

Reduction and Elimination of Humic Acid Fouling in Air Sparged Membrane Distillation Using Nanocarbon Immobilized Membrane

In this paper, we present the treatment of humic acid solution via carbon nanotube immobilized membrane (CNIM) distillation assisted by air sparging (AS). Carbon nanotubes offer excellent hydrophobicity to the modified membrane surface and actively transport water vapor molecules through the membrane to generate higher vapor flux and better rejection of humic acid. The introduction of air sparging in the membrane distillation (MD) system has changed the humic substance fouling by changing the colloidal behavior of the deposits. This modified MD system can sustain a higher run time of separation and has enhanced the evaporation efficiency by 20% more than the regular membrane distillation. The air sparging has reduced the deposition by 30% in weight and offered lesser fouling of membrane surface even after a longer operating cycle. The water vapor flux increased with temperature and decreased as the volumetric concentrating factor (VCF) increased. The mass transfer coefficient was found to be the highest for the air sparged—carbon nanotube immobilized membrane (AS-CNIM) integrated membrane distillation. While the highest change in mass transfer coefficient (MTC) was found for polytetrafluoroethylene (PTFE) membrane with air sparging at 70 °C.     

Solvent-Free Conditions as an Eco-Friendly Strategy for Synthesis of Organophosphorus Compounds

A series of diverse NH- and CH-acids are used for a one-pot synthesis of stable phosphorus ylides and 1,4-diionic organophosphorus compounds by trapping of the zwitterionic intermediate from the reaction between triphenylphosphine and dialkyl acetylenedicarboxylates under solvent-free conditions. The structural geometry for one of the products was confirmed by single crystal X-ray diffraction analysis.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.     

Interaction of Enzyme with Polymer Matrix in Immobilized Enzymes

Thermolysin was immobilized by radiation polymerization of hydroxyalkyl acrylate and tetradecaethylene glycol dimethacrylate monomers at low temperatures in the presence of the enzyme, and the degree of interaction of the enzyme with the polymer matrix was studied by measuring the thermal stability of the immobilized enzyme. The thermal stability was affected by the molecular structure of the monomer; the thermal stability of the immobilized enzyme from hydrophilic monofunctional monomers in the wet state was higher than that from hydrophobic bifunctional monomers. The thermal stability in polymers formed from hydroxy-alkyl acrylates decreased with an increase in the number of methylene units in the monomer, owing to a change of the state of the enzyme trapped in the porous polymer matrix. The enzyme molecule trapped in a hydrophilic porous polymer matrix appeared to be stabilized by interaction with the polymer chains.     

合成固载希夫碱配合物作为配体交换材料

Two new sporopollenin-immobilized Schiff bases, S-[N-(2-aminoetil) salicylaldiimino] and S-[N-(2-aminoetil) benzaldiimino], and their cobalt (Ⅲ) and nickel (Ⅱ) complexes, S-[N-(2-aminoetil) benzaldiimino] aquatriacetato cobalt (Ⅲ), S-[N-(2-aminoetil) salicylaldiimino] aquadiacetato cobalt (Ⅲ), S-[N-(2-aminoetil) benzaldiimino] diacetato nickel (Ⅱ), and S-[N-(2-aminoetil) salicylaldiimino] diacetato nickel (Ⅱ), were synthesized onto a chemically modified sporopollenin with ethylenediamine. The immobilized ligands and their metal complexes were characterized by thermal analysis and spectroscopic techniques such as infrared, ultraviolet-visible, and atomic absorption spectrometry. Immobilized Schiff base metal complexes, S-[N-(2-aminoetil) benzaldiimino] aquatriacetato cobalt (Ⅲ) and S-[N-(2-aminoetil) salicylaldiimino] aquadiacetato cobalt (Ⅲ), were used as ligand exchanger media to investigate ligand adsorption behavior of methylene blue (MB) with column technique. The result shows that the chelation of methylene blue with S-[N-(2-aminoetil) salicylaldiimino] aquadiacetato cobalt (Ⅲ) complex increases ligand adsorption capacity.     

Practical Applications of Tetraene Macrolide Antibiotic Lucensomycin as an Eco-Friendly Fungicide

Russian Journal of General Chemistry - This review systematically describes the published data on the preparation, physicochemical properties, chemical structure, and biological activity of...     

介孔分子筛上的蛋白质直接电化学

将介孔分子筛用于不同含血红素蛋白质的直接电子传递研究,分别研究了辣根过氧化物酶、血红蛋白和肌红蛋白在六方介孔硅(HMS)上的直接电化学,探讨了介孔分子筛与这些蛋白质间的相互作用,构建了过氧化氢和亚硝酸根的新型的生物传感器. 这些工作扩展了HMS在蛋白质固定、直接电子传递研究和无试剂生物传感器制备方面的应用.     

纳米材料热力学的研究现状及展望

本文分别从纳米材料的热容、晶格参数、结合能、内聚能、界面能、界面应力、热稳定性、熔点、熔解焓、熔解熵、相图及纳米材料参与反应时反应体系的化学平衡、吸附能等方面对纳米材料热力学的研究进展进行了阐述,并对纳米材料热力学的研究和应用前景进行了展望。     

Development and Application of an Immobilized Enzyme Electrode for the Determination of Sulfite in Foods and Feeds

Abstract

An enzyme electrode was developed using the enzyme sulfite oxidase (EC 1.8.3.1) immobilized onto pig intestine. All experimental parameters such as pH, temperature, buffer constituent concentration, etc., were thoroughly investigated and optimized when appropriate. Hydrogen peroxide was monitored amperometrically. The response to sulfite concentration was linear in the range of 5.2 × 10^?6 to 1.0×10^?3M. The proposed method was found to have a correlation coefficient of 0.952 when evaluated versus the standard titration method.     

以硅胶为载体的交联壳聚糖作为亲和层析填料基质的研究

采用硅胶为载体的交联壳聚糖（CTS－SiO2）作为亲和层析填料基质，对其卵清蛋白的偶联能力，以及亲和纯化小鼠抗卵清蛋白抗体效果等进行了研究。结果显示卵清蛋白能方便地用二醛偶联于CTS－SiO2基质，该新型亲和层析填料稳定性高，选择性好，非特异性吸附小，每克交联壳聚糖上可偶联卵清蛋白54.25mg，用该填料可有效地亲和吸附小鼠抗卵清蛋白抗体，并可用碱性缓冲液将该抗体洗脱，初步显示出较好的分离纯化效果。     

Effect of Concentration of the Diazoalcene Molybdenum Complex Immobilized in Ureasil Matrix

The complex trans-[FMo(NNCHCHCHCH₂CH₃)(Ph₂PCH₂CH₂PPh₂)₂][BPh₄], was dispersed in a hybrid matrix synthesized by a sol-gel process. The host matrix of the so-called ureasil is a network of silica to which oligopolyoxyethylene chains [POE, (OCH₂CH₂)_n] are grafted by means of urea cross-links. The free complex and sol-gel materials were characterized by thermal analysis (DSC), surface analysis (XPS) and spectroscopic methods (FT-IR and UV/Vis). The data gathered indicates that the molybdenum(IV) complex is immobilized in the host matrix, and it exhibits structural properties different from those of the free form. These differences could arise either from distortions caused by steric effects imposed by the structure of hybrid matrix or by interactions with the matrix. These materials shows potential applications in heterogeneous catalysis in mild conditions.     

微生物燃料电池在传感分析中的应用及研究进展

微生物燃料电池(Microbial fuel cell,MFC)是一种利用微生物将化学能直接转化为电能的装置.近年来,除改善微生物燃料电池的输出性能外,研究者也不断开发其在传感分析中的应用.基于微生物燃料电池的传感分析装置无需外加电源,具有操作简单、可连续检测等优点,是一种极具应用前景的传感分析技术.本文依据这些传感分析装置的用途进行分类,主要综述了微生物燃料电池在检测分析生化需氧量(BOD)、挥发性脂肪酸、毒性物质、微生物活性和数量以及其它方面的研究,并对其发展趋势和应用前景进行了展望.     

我国化学发展前景

化学是一门实用的学科,它与数学、物理学等学科共同成为当代自然科学迅猛发展的基础.化学的核心知识已经应用于自然科学的方方面面,与其它学科相辅相成,构成了创造自然、改造自然的强大力量.     

聚甲基丙烯酸甲酯固定化碳纳米管作为MALDI基质的研究

将聚甲基丙烯酸甲酯材料在多壁碳纳米管表面原位聚合, 利用这种修饰的碳纳米管作为基质辅助激光解析离子化(MALDI)的基质, 利用修饰后的碳纳米管可以“溶解”的特性实现了稳定的MALDI离子化, 并且消除了在低质量端的基质噪音. 此类聚合物衍生的碳纳米管具有相对较好的亲水性表面, 可“溶解”在溶剂中. 此方法适用于有机小分子、多肽、聚合物和蛋白质酶解肽段的质谱分析. 实验表明聚甲基丙烯酸甲酯固定化碳纳米管能有效地吸收和传递激光能量, 可与样品充分地分散混合, 质谱检测背景低, 重现性好, 具有较宽的可测质量范围. 此方法在小分子快速检测和蛋白质组学方面有很大的应用前景.     

荧光微球的制备技术及其应用进展

荧光微球作为一类特殊的功能微球,以其稳定的形态结构、窄的粒径分布、好的单分散性和高效的发光效率,吸引了国内外研究者广泛的关注,且在许多领域尤其是生物医学领域有很重要的应用.但是就其发展情况来看,还是远远不够的.尤其是在我国,目前应用的荧光微球基本上依赖进口,因此,如能使荧光微球国产化,将对我国生物医学等领域的发展具有重要的意义.本文主要对荧光微球的定义、分类、制备技术及其应用进行了综述,并对荧光微球的研究及应用前景进行了展望.     

脱水Ni-Fe类水滑石的制备及其作为环保型催化剂用于生物质糠醛的高选择性缩醛化反应

合成了含硝酸根离子的脱水Ni-Fe类水滑石（Ni-Fe HTLCs）并将其应用于室温下的糠醛缩醛化反应。脱水Ni-Fe HTLCs对糠醛缩醛化反应显示出高选择性并基本实现糠醛的完全转化。作为耐水的路易斯酸和脱水剂,脱水Ni-Fe HTLCs被证明是适用于糠醛缩醛化反应的高效双功能催化剂。通过研究发现,脱除Ni-Fe HTLCs中水分导致颗粒收缩并增强层板间硝酸根离子间的电荷互斥,Ni-Fe HTLCs中弱酸性位点在糠醛缩醛化中发挥重要作用,脱水可改变酸性位点结构并增强其活性。脱水Ni-Fe HTLCs可吸收缩醛化反应中产生的大部分水分,但吸水后Ni-Fe HTLCs的结构并不能完全恢复,这可能是由扩散进入HTLCs层板间的有机分子导致。     

Phytase Production and Development of an Ideal Dephytinization Process for Amelioration of Food Nutrition Using Microbial Phytases

Development of an ideal process for reduction of food phytates using microbial phytases is a demanding task by all food and feed industries all over the world. Phytase production by Bacillus subtilis subsp. subtilis JJBS250 isolated from soil sample was optimized in submerged fermentation using statistical tools. Among all the culture variables tested, sucrose, sodium phytate and Tween-80 were identified as the most significant variables using the Placket–Burman design. Further optimization of these variables resulted in a 6.79-fold improvement in phytase production (7170 U/L) as compared to unoptimized medium. Supplementation of microbial phytases (fungal and bacterial) resulted in improved bioavailability of nutritional components with the concomitant liberation of inorganic phosphorus, reducing sugar, soluble protein and amino acids, thus mitigating anti-nutritional properties of phytic acid.