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71.
Dr. Christian Dubiella Dr. Haissi Cui Prof. Dr. Michael Groll 《Angewandte Chemie (International ed. in English)》2016,55(42):13330-13334
Electrophiles are commonly used for the inhibition of proteases. Notably, inhibitors of the proteasome, a central determinant of cellular survival and a target of several FDA‐approved drugs, are mainly characterized by the reactivity of their electrophilic head groups. We aimed to tune the inhibitory strength of peptidic sulfonate esters by varying the leaving groups. Indeed, proteasome inhibition correlated well with the pKa of the leaving group. The use of fluorophores as leaving groups enabled us to design probes that release a stoichiometric fluorescence signal upon reaction, thereby directly linking proteasome inactivation to the readout. This principle could be applicable to other sulfonyl fluoride based inhibitors and allows the design of sensitive probes for enzymatic studies. 相似文献
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《Biomedical chromatography : BMC》2017,31(6)
Triterpenic acids are widely distributed in many fruits and are known for their medicinal benefits. The study of bioavailability has been an important task for a better understanding of the triterpenic acids. Although many methods based on fluorescence labeling for triterpenic acid determination have been established, these reported methods needed anhydrous conditions, which are not suitable for the convenient study of triterpenic acid bioavailability. Inspired by that, a versatile method, which overcomes the difficulty of the reported methods, has been first developed in this study. The novel method using 2‐[12‐benzo[b ]acridin‐5‐ (12H)‐yl]‐acetohydrazide (BAAH) as the fluorescence labeling reagent coupled with high‐performance liquid chromatography with fluorescence detection was first developed for the study of triterpenic acid bioavailability. Furthermore, the labeling conditions have been optimized in order to achieve the best fluorescence labeling yield. Under the optimal conditions, the quantitative linear range of analytes was 2–1000 ng mL−1, and the correlation coefficients were >0.9998. The detection limits for all triterpenic acid derivatives were achieved within the range of 0.28–0.29 ng mL−1. The proposed method was successfully applied to the study of triterpenic acid bioavailability with excellent applicability and good reproducibility. 相似文献
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Atom transfer radical polymerization (ATRP) of MMA was conducted using 2‐(4‐chloromethyl‐phenyl)‐benzoxazole as initiator, CuCl as catalyst, and PMDETA as ligand. The results show that the polymerization is a first order reaction with respect to monomer concentration. The polymerization displayed living character as evidenced by a liner increase of monomer weight with conversation and a relatively narrow distribution (Mn/Mw range from 1.30 to 1.45). The structure of PMMA was analyzed by 1H‐NMR and proved the polymerization could be controlled to some degree. The optical property of the initiator was well preserved in the resulting PMMA, and the end‐functionalized PMMA exhibited fluorescent emission at 360 nm whether in DMF solution or in film state. 相似文献
78.
Tongmou Geng Guofeng Chen Can Zhang Lanzhen Ma Weiyong Zhang Hongyu Xia 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(11):1004-1011
AbstractA mesoporous covalent triazine framework, PCPDI, was synthesized via an aromatic nitrile trimerization reaction of N,N′-di(4-cyanphenyl)- 3,4,9,10-tetracarboxydiimide (CPDI) by CF3SO3H catalyzed at 40?°C and this method avoids the use of noble metal catalyzers or high temperature reaction. PCPDI exhibits high thermal stability and strong fluorescence. The PCPDI shows ultrahigh sensitivity to tracing o-nitrophenol in chloroform with KSV constant of 1.74?×?105 L mol?1 and detection limit (LOD) of 1.72?×?10?11?mol L?1. 相似文献
79.
Mousa Ghaemy Samaneh Sharifi Seyed Mojtaba Amini Nasab Mehdi Taghavi 《高分子科学杂志,A辑:纯化学与应用化学》2013,50(5):487-497
Two new symmetrical diamines were designed and synthesized having different functional groups such as a pair of phenyl ether linkages, 2,3-diaryl substituted imidazole rings and CF3 groups as pendant, and characterized by FT-IR, 1H and 13C-NMR spectroscopy and elemental analysis. A series of new fluorescent poly(imide-ether)s (PIEs) was prepared by polymerization of the diamines with commercial tetracarboxylic dianhydrides such as pyromellitic dianhydride and 3,3′,4,4′-benzophenone tetracarboxylic dianhydride. The resulting PIEs were amorphous and had intrinsic viscosity [η] in the range of 0.42–0.51 dL/g. The weight average molecular weights (Mw) of these polymers were measured by GPC and were in the range of 28658–35595 g/mol with molecular weight distribution (MWD) of 2.12–2.27. These polymers were readily soluble in a variety of organic solvents and formed low-colored and flexible thin films with cut-off wavelength (λ0) in the range of 385–420 nm, and all PIEs films exhibited high optical transparency. They also possessed good thermal stability with 10% weight loss temperatures (T10%) in the range 486–537°C in N2. The glass transition temperatures (Tg) of PIEs are in the range 251–324°C. These polymers showed fluorescence emission in film and in solution at 459–476 nm with the quantum yields in the range 4–12%. 相似文献
80.
Mauro Formica Luca Giorgi Eleonora Macedi Giovanni Piersanti Maria Antonietta Varrese 《Supramolecular chemistry》2013,25(6):365-379
The synthesis and anion binding studies of the new neutral receptor 1,1′-(2,2′-(4,10-dimethyl-1,4,7,10-tetraazacyclododecane-1,7-diyl)bis(2-oxoethane-2,1-diyl))bis(3-(3,5-bis(trifluoromethyl)phenyl)urea) (L1) are reported. L1 is a macrocyclic ligand containing the 3,5-trifluoromethylphenylureido-binding fragment attached as a side arm on the tetraazacyclododecane. L1 is soluble in numerous organic solvents; the binding properties of L1 towards several simple anions (G) were investigated by NMR, UV–vis and fluorescence techniques in DMSO and CH3CN solutions. L1 is able to bind F? , Cl? and AcO? in both solvents; in addition, it binds Br? in CH3CN. Fluoride shows the highest constant values in the halide series (F? > Cl? > Br? ) and AcO? is the most strongly bound among all the anions investigated. L1 is able to signal the presence of the anions in solution by fluorescence change; in the case of acetate, this occurs in the visible range. 相似文献