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101.
Fluorescent In Situ Targeting Probes for Rapid Imaging of Ovarian‐Cancer‐Specific γ‐Glutamyltranspeptidase 下载免费PDF全文
Feiyi Wang Prof. Ying Zhu Li Zhou Liang Pan Zhifen Cui Qiang Fei Sihang Luo Dr. Dun Pan Prof. Rui Wang Prof. Chunchang Zhao Prof. He Tian Prof. Chunhai Fan 《Angewandte Chemie (International ed. in English)》2015,54(25):7349-7353
γ‐Glutamyltranspeptidase (GGT) is a tumor biomarker that selectively catalyzes the cleavage of glutamate overexpressed on the plasma membrane of tumor cells. Here, we developed two novel fluorescent in situ targeting (FIST) probes that specifically target GGT in tumor cells, which comprise 1) a GGT‐specific substrate unit (GSH), and 2) a boron–dipyrromethene (BODIPY) moiety for fluorescent signalling. In the presence of GGT, sulfur‐substituted BODIPY was converted to amino‐substituted BODIPY, resulting in dramatic fluorescence variations. By exploiting this enzyme‐triggered photophysical property, we employed these FIST probes to monitor the GGT activity in living cells, which showed remarkable differentiation between ovarian cancer cells and normal cells. These probes represent two first‐generation chemodosimeters featuring enzyme‐mediated rapid, irreversible aromatic hydrocarbon transfer between the sulfur and nitrogen atoms accompanied by switching of photophysical properties. 相似文献
102.
Nannocystin A: an Elongation Factor 1 Inhibitor from Myxobacteria with Differential Anti‐Cancer Properties 下载免费PDF全文
Philipp Krastel Silvio Roggo Markus Schirle Nathan T. Ross Francesca Perruccio Peter Aspesi Jr. Thomas Aust Kathrin Buntin David Estoppey Brigitta Liechty Felipa Mapa Klaus Memmert Howard Miller Xuewen Pan Ralph Riedl Christian Thibaut Jason Thomas Trixie Wagner Eric Weber Xiaobing Xie Esther K. Schmitt Dr. Dominic Hoepfner 《Angewandte Chemie (International ed. in English)》2015,54(35):10149-10154
Cultivation of myxobacteria of the Nannocystis genus led to the isolation and structure elucidation of a class of novel cyclic lactone inhibitors of elongation factor 1. Whole genome sequence analysis and annotation enabled identification of the putative biosynthetic cluster and synthesis process. In biological assays the compounds displayed anti‐fungal and cytotoxic activity. Combined genetic and proteomic approaches identified the eukaryotic translation elongation factor 1α (EF‐1α) as the primary target for this compound class. Nannocystin A ( 1 ) displayed differential activity across various cancer cell lines and EEF1A1 expression levels appear to be the main differentiating factor. Biochemical and genetic evidence support an overlapping binding site of 1 with the anti‐cancer compound didemnin B on EF‐1α. This myxobacterial chemotype thus offers an interesting starting point for further investigations of the potential of therapeutics targeting elongation factor 1. 相似文献
103.
Diselenophosphate‐Induced Conversion of an Achiral [Cu20H11{S2P(OiPr)2}9] into a Chiral [Cu20H11{Se2P(OiPr)2}9] Polyhydrido Nanocluster 下载免费PDF全文
Dr. Rajendra S. Dhayal Jian‐Hong Liao Dr. Xiaoping Wang Dr. Yu‐Chiao Liu Dr. Ming‐His Chiang Dr. Samia Kahlal Prof. Jean‐Yves Saillard Prof. C. W. Liu 《Angewandte Chemie (International ed. in English)》2015,54(46):13604-13608
A polyhydrido copper nanocluster, [Cu20H11{Se2P(OiPr)2}9] ( 2H ), which exhibits an intrinsically chiral inorganic core of C3 symmetry, was synthesized from achiral [Cu20H11{S2P(OiPr)2}9] ( 1H ) of C3h symmetry by a ligand‐exchange method. The structure has a distorted cuboctahedral Cu13 core, two triangular faces of which are capped along the C3 axis, one by a Cu6 cupola and the other by a single Cu atom. The Cu20 framework is further stabilized by 9 diselenophosphate and 11 hydride ligands. The number of hydride, phosphorus, and selenium resonances and their splitting patterns in multinuclear NMR spectra of 2H indicate that the chiral Cu20H11 core retains its C3 symmetry in solution. The 11 hydride ligands were located by neutron diffraction experiments and shown to be capping μ3‐H and interstitial μ5‐H ligands (in square‐pyramidal and trigonal‐bipyramidal cavities), as supported by DFT calculations on [Cu20H11(Se2PH2)9] ( 2H′ ) as a simplified model. 相似文献
104.
In this research, the graphene with excellent dispersity is prepared successfully by introducing gold nanoparticle to separate the individual sheets. Various techniques are adopted to characterize the prepared graphene and graphene-gold nanoparticle composite materials. This fabricated new composite material is used as the support material to construct a novel tyrosinase based biosensor for detection of bisphenol A (BPA). The electrochemical performances of the proposed new enzyme biosensor were investigated by differential pulse voltammetry (DPV) method. The proposed biosensor exhibited excellent performance for BPA determination with a wide linear range (2.5 × 10−3–3.0 μM), a highly reproducible response (RSD of 2.7%), low interferences and long-term stability. And more importantly, the calculated detection limit of the proposed biosensor was as low as 1 nM. Compared with other detection methods, this graphene-gold nanoparticle composite based tyrosinase biosensor is proved to be a promising and reliable tool for rapid detection of BPA for on-site analysis of emergency BPA related pollution affairs. 相似文献
105.
Glucose detection plays very important roles in diagnostics and management of diabetes. The search for novel catalytic materials with appropriate architectures is the key step in the fabrication of highly sensitive glucose sensors. In this work, α-Ni(OH)2 roselike structures (Ni(OH)2-RS) assembled from nanosheet building blocks were successfully synthesized by a hydrothermal method through the hydrolysis of nickel chloride in the mixed solvents of water and ethanol with the assistance of polyethylene glycol (PEG). The structure and morphology of the roselike α-Ni(OH)2 were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FE-SEM), X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD) and N2 adsorption–desorption isotherm measurement. TEM and FE-SEM images showed that the synthesized Ni(OH)2 was roselike and the size of the leaf-shaped nanosheet was about 5 nm in thickness, which leads to larger active surface areas and faster electron transfer for the detection of glucose. Compared with the bare GCE and bulk Ni(OH)2/GCE, the Ni(OH)2-RS/GCE had higher catalytic activity toward the oxidation of glucose. Under the optimal conditions, the Ni(OH)2-RS/GCE offers a variety of merits, such as a wide linear response window for glucose concentrations ranging from 0.87 μM to 10.53 mM, short response time (3 s), a lower detection limit of 0.08 μM (S/N = 3), as well as long term stability and repeatability. 相似文献
106.
107.
Yanhua Huang Yuzhi WangQi Pan Ying WangXueqin Ding Kaijia XuNa Li Qian Wen 《Analytica chimica acta》2015
Four kinds of green deep eutectic solvents (DESs) based on choline chloride (ChCl) have been synthesized and coated on the surface of magnetic graphene oxide (Fe3O4@GO) to form Fe3O4@GO-DES for the magnetic solid-phase extraction of protein. X-ray diffraction (XRD), vibrating sample magnetometer (VSM), Fourier transform infrared spectrometry (FTIR), field emission scanning electron microscopy (FESEM) and thermal gravimetric analysis (TGA) were employed to characterize Fe3O4@GO-DES, and the results indicated the successful preparation of Fe3O4@GO-DES. The UV–vis spectrophotometer was used to measure the concentration of protein after extraction. Single factor experiments proved that the extraction amount was influenced by the types of DESs, solution temperature, solution ionic strength, extraction time, protein concentration and the amount of Fe3O4@GO-DES. Comparison of Fe3O4@GO and Fe3O4@GO-DES was carried out by extracting bovine serum albumin, ovalbumin, bovine hemoglobin and lysozyme. The experimental results showed that the proposed Fe3O4@GO-DES performs better than Fe3O4@GO in the extraction of acidic protein. Desorption of protein was carried out by eluting the solid extractant with 0.005 mol L−1 Na2HPO4 contained 1 mol L−1 NaCl. The obtained elution efficiency was about 90.9%. Attributed to the convenient magnetic separation, the solid extractant could be easily recycled. 相似文献
108.
109.
Feng Zhang Li Pan Juhee Choi Vikram Mehar John T. Diulus Aravind Asthagiri Jason F. Weaver 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2015,127(47):14113-14117
Achieving selective C H bond cleavage is critical for developing catalytic processes that transform small alkanes to value‐added products. The present study clarifies the molecular‐level origin for an exceptionally strong preference for propane to dissociate on the crystalline PdO(101) surface via primary C H bond cleavage. Using reflection absorption infrared spectroscopy (RAIRS) and density functional theory (DFT) calculations, we show that adsorbed propane σ‐complexes preferentially adopt geometries on PdO(101) in which only primary C H bonds datively interact with the surface Pd atoms at low propane coverages and are thus activated under typical catalytic reaction conditions. We show that a propane molecule achieves maximum stability on PdO(101) by adopting a bidentate geometry in which a H Pd dative bond forms at each CH3 group. These results demonstrate that structural registry between the molecule and surface can strongly influence the selectivity of a metal oxide surface in activating alkane C H bonds. 相似文献