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981.
Vendrell M Krishna GG Ghosh KK Zhai D Lee JS Zhu Q Yau YH Shochat SG Kim H Chung J Chang YT 《Chemical communications (Cambridge, England)》2011,47(29):8424-8426
The diversification of the BODIPY scaffold has been hindered by its controversial adaptability to solid-phase chemistry. Herein we report the first solid-phase synthesis of a BODIPY library in high purities. We screened the library against a set of proteins, identified an immunoglobulin fluorescent sensor (Ig Orange) and confirmed its binding by SPR experiments. 相似文献
982.
Li C Wang L Jiang Y Hu M Li S Zhai Q 《Applied biochemistry and biotechnology》2011,165(7-8):1691-1707
Chloroperoxidase (CPO) is thought to be the most versatile heme-containing enzyme with enormous applications in organic synthesis, biotransformation, pharmaceutical production, and detoxification of environmental pollutants. Any improvement in the stability of this enzyme will greatly enhance its application in the mentioned areas. In the present study, the effects of three polysaccharides (soluble starch, β-cyclodextrin, and dextrin) on the stability of CPO at elevated temperatures (20, 30, 35, 40, and 50 °C) or in aqueous-organic solvents media (methanol, dioxane, DMSO, and DMF) were investigated. An improved catalytic performance of CPO was observed in the presence of a small amount of the three polysaccharides, where dextrin provided the most effective promotion. The changes of enzyme structure and microenvironment around heme in the presence of additives were studied by fluorescence, circular dichroism, and UV-vis spectra analyses, as well as kinetic parameters measurement. A catalytically favorable structure of CPO was induced, including the strengthening of the α-helix structure and more exposure of heme for easy access of the substrate, resulting in an increase of catalytic turnover frequency (k (cat)) and the improvement of affinity and selectivity of CPO to substrate. The results revealed that the introduction of trace soluble starch, β-cyclodextrin, and dextrin (<10 μmol/L) in reaction media was an effective strategy for the enhancement of the thermodynamic and the operational stability of the enzyme, which are promising in view of the industrial applications of this versatile biological catalyst. 相似文献
983.
Re(VII) extraction and separation from Mo(VI) by levextrel resins containing trialkyl amine 总被引:1,自引:0,他引:1
K. X. Jiang Y. C. Zhai W. Shan Y. Xiong X. F. Wang Z. N. Lou 《Russian Journal of Inorganic Chemistry》2011,56(7):1153-1156
A synthetic method of novel trialkyl amine (N235, R3N, R = C8–C10) Levextrel resin was described in this paper. The extraction behavior of rhenium(VII) and molybdenum(VI) with this N235 Levextrel
resin has been studied. The mechanism of extraction of Re(VII) with the N235 Levextrel resin has been discussed briefly through
equi-molar series method and the conventional slope analysis method. The optimal conditions of extraction and separation Mo(VI)
and Re(VII) with the N235 Levextrel resin were determined. Also, its excellent extraction characteristics for Re(VII) were
confirmed by extraction and stripping tests in a analog liquid solution containing Mo(VI) and Re(VII). 相似文献
984.
Anion photoelectron spectroscopy and theoretical calculations are combined to probe the structures and chemical bonding of two boron-rich oxide clusters, B(5)O(3)(-) and B(6)O(3)(-), which are shown to be appropriately formulated as B(2)(BO)(3)(-) and B(3)(BO)(3)(-), respectively. The anion clusters are found to each possess a bridging η(2)-BO group, as well as two terminal BO groups and are analogs of B(2)H(3)(-) and B(3)H(3)(-). This finding advances the boronyl chemistry and helps establish the isolobal analogy between boron-rich oxide clusters and boranes. 相似文献
985.
Lee JJ Lee SC Zhai D Ahn YH Yeo HY Tan YL Chang YT 《Chemical communications (Cambridge, England)》2011,47(15):4508-4510
A bodipy probe was developed for site-specific labeling of tagged proteins inside live cells which displays a large spectral change upon covalent coupling to the designed peptide that contains two pairs of Arg-Cys. 相似文献
986.
Zou C Zhang L Zhai L Lin D Gao J Li Q Yang Y Chen X Huang S 《Chemical communications (Cambridge, England)》2011,47(18):5256-5258
We have demonstrated that quaternary Cu(x)In(x)Zn(2(1-x))S(2) nanobelts could be synthesized through a facile solution-based method. The composition and band gap of quaternary nanobelts can be tuned within the broad range by changing the relative ratio of precursors. The growth mechanism of quaternary nanobelts was deduced to be catalyst-assisted growth. 相似文献
987.
Background
The importance of the isatinic quinolyl hydrazones arises from incorporating the quinoline ring with the indole ring. Quinoline ring has therapeutic and biological activities whereas, the indole ring occurs in Jasmine flowers and Orange blossoms. As a ligand, the isatin moiety is potentially ambidentate and can coordinate the metal ions either through its lactam or lactim forms. In a previous study, the ligational behavior of a phenolic quinolyl hydrazone towards copper(II)- ions has been studied. As continuation of our interest, the present study is planned to check the ligational behavior of an isatinic quinolyl hydrazone.Results
New homo- and heteroleptic copper(II)- complexes were obtained from the reaction of an isatinic quinolyl hydrazone (HL) with several copper(II)- salts viz. Clˉ, Brˉ, NO3ˉ, ClO4 -, SO4 2- and AcO-. The obtained complexes have Oh, Td and D4h- symmetry and fulfill the strong coordinating ability of Clˉ, Brˉ, NO3ˉ and SO4 2- anions. Depending on the type of the anion, the ligand coordinates the copper(II)- ions either through its lactam (NO3ˉ and ClO4 -) or lactim (the others) forms.Conclusion
The effect of anion for the same metal ion is obvious from either the geometry of the isolated complexes (Oh, Td and D4h) or the various modes of bonding. Also, the obtained complexes fulfill the strong coordinating ability of Clˉ, Brˉ, NO3ˉ and SO4 2- anions in consistency with the donor ability of the anions. In case of copper(II)- acetate, a unique homoleptic complex (5) was obtained in which the AcO- anion acts as a base enough to quantitatively deprotonate the hydrazone. The isatinic hydrazone uses its lactim form in most complexes. 相似文献988.
989.
Zeolite A and A + X mixtures were prepared from coal-fly ash procured from China by using an alkali fusion method. X-ray diffraction
showed that both the materials were crystalline and reproducible. Scanning Microscopy revealed that pure zeolite A particles
have cubic morphology while the mixture shows intergrowth of cubic and pyramidal crystals. The surface area for A + X mixture
was around 330 m2/g which is higher than zeolite A, however, lower than typical X zeolite. CO2 and N2 adsorption isotherms were measured and the data was fitted by the Dual Site Langmuir equation. These zeolites were then tested
for CO2 capture at different temperatures in a process with a nine step cycle. When compared with 13X zeolites at higher temperature
(∼90 °C), both the zeolite A + X mixture and zeolite A prepared from fly ash showed better performance in CO2 capture from flue gas because they have higher selectivity of CO2 over N2. 相似文献
990.
实验发现,阿奇霉素对联吡啶钌的电致化学发光(ECL)具有显著的增强作用。据此,建立了以金电极为工作电极的测定阿奇霉素ECL分析新方法。采用了循环伏安(CV)和ECL法,研究了阿奇霉素对联吡啶钌体系的电化学行为和ECL行为的增强作用。结果表明,在最佳条件下,阿奇霉素浓度在2.0×10-4~4.0×10-7 mol/L范围内与相对发光强度呈线性关系,其线性回归方程为I计数=22.848×106 C+221.8(r=0.9981,n=12)。检出限为3.00×10-9 mol/L(S/N=3)。连续平行测定1.0×10-5 mol/L的阿奇霉素标品溶液10次,发光强度值的相对标准偏差(RSD)为2.09%。对样品进行回收率试验,回收率在95.0%~102.0%之间,RSD为2.40%(n=5)。该方法具有较高的选择性和灵敏度,样品处理简单快速,用于药物中阿奇霉素的测定,结果满意。 相似文献