518-45-6Relevant academic research and scientific papers
Copper(II)-Silver(I) Macrocyclic Metal-Organic Framework: A Highly Efficient Reusable Triplet Oxygen Collector and Singlet Oxygen Generator
Wang, Jian-Cheng,Yang, Jing,Wang, Shen-Qing,Ma, Jian-Ping,Dong, Yu-Bin
, p. 1049 - 1052 (2017)
The generation of highly reactive oxygen (1O2) is very significant for a variety of applications such as degradation, bleaching, chemical synthesis, photodynamic therapy for tumor treatment, and others. Herein, we report a novel peroxide-dianion-embedded bimetallic macrocycle, [O22-@Ag4Cu4L4]2+ (2), that can completely release the inserted peroxide dianion as the singlet oxygen (1O2) via a H+-assisted disproportionation process in methanol. Notably, the resulting empty Ag4Cu4L4(ClO4)4 (3) is able to trap oxygen (3O2) from air and fixes it in the macrocycle host as a peroxide dianion; furthermore, it releases it as 1O2 again in the presence of H+. So, the bimetallic macrocycle [Ag4Cu4L4]4+ herein behaves as a highly efficient reusable triplet oxygen receptor and singlet oxygen generator.
Stopped-flow enzyme assays on a chip using a microfabricated mixer
Burke, Brian J.,Regnier, Fred E.
, p. 1786 - 1791 (2003)
This paper describes a microfabricated enzyme assay system including a micromixer that can be used to perform stopped-flow reactions. Samples and reagents were transported into the system by electroosmotic flow (EOF). Streams of reagents were merged and passed through the 100-pL micromixer in a system of roughly 6 nL volume. β-Galactosidase (β-Gal) was chosen as a model enzyme for these studies and was used to convert the substrate fluorescein mono-β-D-galactopyranoside (FMG) into fluorescein. Results obtained with microfabricated systems using the micromixer compared well to those obtained with an external T mixing device. In contrast, assays performed in a microfabricated device by merging two streams and allowing mixing to occur by lateral diffusion did not compare well. Using the microfabricated mixer, Km and kcat values of 75 ± 13 μM and 44 ± 3 s-1 were determined. These values compare well to those obtained with the conventional stopped-flow apparatus for which Km was determined to be 60 ± 6 μM and kcat was 47 ± 4 s-1. Enzyme inhibition assays with phenylethyl-β-D-thiogalactoside (PETG) were also comparable. It was concluded that kinetically based, stopped-flow enzyme assays can be performed in 60 s or less with a miniaturized system of roughly 6 nL liquid volume when mixing is assisted with the described device.
Combinatorial discovery of peptide dendrimer enzyme models hydrolyzing isobutyryl fluorescein
Maillard, Noelie,Biswas, Rasomoy,Darbre, Tamis,Reymond, Jean-Louis
, p. 310 - 320 (2011)
Two 6750-membered one-bead-one-compound peptide dendrimer combinatorial libraries L (X4)8(LysX3)4(LysX 2)2LysX1 (X1-4 = 14 different amino acids or deletion, Lys = branching lysine residue) and AcL (with N-terminal acetylation) were prepared by split-and-mix solid phase peptide synthesis. Screening toward fluorogenic substrates for esterase and aldolase activities using the in silica off-bead assay (N. Maillard et al., J. Comb. Chem.2009, 11, 667-675) and bead decoding by amino acid analysis revealed histidine containing sequences active against fluorescein diacetate. Isobutyryl fluorescein, a related hydrophobic fluorogenic substrate, was preferentially hydrolyzed by dendrimers from library AcL containing hydrophobic residues such as AcH3 (AcHis)8(LysLeu)4(LysVal)2LysLysOH, compared to simple oligohistidine peptides as reference catalysts. Polycationic dendrimers from library L with multiple free N-termini such as H8 (His) 8(LysβAla)4(LysThr)2LysaProNH2 (aPro = (2S,4S)-4-aminoproline) showed stronger reactivity toward 8-acetoxypyrene-1,3,6-trisulfonate with partial acylation of N-termini. These experiments highlight the role of noncatalytic amino acids to determine substrate selectivity in peptide dendrimer esterase models.
Extension of the applicable range of fluorescein: A fluorescein-based probe for Western blot analysis
Kamiya, Mako,Urano, Yasuteru,Ebata, Nobuyoshi,Yamamoto, Masami,Kosuge, Jyunichi,Nagano, Tetsuo
, p. 5439 - 5441 (2005)
(Chemical Equation Presented) The new star of Westerns: A highly sensitive fluorescence probe for alkaline phosphatase (ALP) based on a fluorescein derivative has been prepared and found to be suitable for use in Western blot analysis. The probe 1 is nonf
Peptide dendrimer enzyme models for ester hydrolysis and aldolization prepared by convergent thioether ligation
Uhlich, Nicolas A.,Darbre, Tamis,Reymond, Jean-Louis
, p. 7071 - 7084 (2011)
Peptide dendrimers with multiple histidines or N-terminal prolines efficiently catalyze ester hydrolysis or aldol reactions in aqueous medium. Part of the catalytic proficiency of these dendritic enzyme models stems from multivalency effects observed in G2, G3 and G4 dendrimers displaying multiple catalytic groups in their branches. To study multivalency in higher generation systems, G4, G5 and G6 peptide dendrimers were prepared by a convergent assembly. Thus, peptide dendrimers bearing four or eight chloroacetyl groups at their N-termini underwent multiple thioether ligation with G2 and G3 peptide dendrimers with a cysteine residue at their focal point, to give G4, G5 and G6 dendrimers containing up to 341 amino acids, including multiple histidines or N-terminal prolines. While the efficiency of the esterase catalysts was comparable to that of their lower generation analogs, a remarkable reactivity increase was observed in G5 and G6 aldolase dendrimers.
A fluoresceinylcarbonate-based fluorescent probe for the sensitive detection of biothiols in a HEPES buffer and its cellular expression
Hong, Keum-Hee,Kim, Dae Il,Kwon, Hyockman,Kim, Hae-Jo
, p. 978 - 982 (2014)
A fluoresceinylcarbonate-based fluorescent probe (1) with a disulfide bond was designed for the detection of biothiols in an aqueous solvent. The probe showed a more rapid and sensitive response to biothiols than other various amino acids through the disulfide bond cleavage and the subsequent intramolecular cyclization. When glutathione was added to the probe, fluorescence of 1 was significantly enhanced and was observable with the naked eye and in living cells. The Royal Society of Chemistry 2014.
Controlled initiation of enzymatic reactions in micrometer-sized biomimetic compartments
Karlsson, Anders,Sott, Kristin,Markstr?m, Martin,Davidson, Max,Konkoli, Zoran,Orwar, Owe
, p. 1609 - 1617 (2005)
We present a technique to initiate chemical reactions involving few reactants inside micrometer-scale biomimetic vesicles (10-12 to 10-15 L) integral to three-dimensional surfactant networks. The shape of these networks is under dyna
Readily Available Fluorescent Probe for Carbon Monoxide Imaging in Living Cells
Feng, Weiyong,Liu, Dandan,Feng, Shumin,Feng, Guoqiang
, p. 10648 - 10653 (2016)
Carbon monoxide (CO) is an important gasotransmitter in living systems and its fluorescent detection is of particular interest. However, fluorescent detection of CO in living cells is still challenging due to lack of effective probes. In this paper, a readily available fluorescein-based fluorescent probe was developed for rapid detection of CO. This probe can be used to detect CO in almost wholly aqueous solution under mild conditions and shows high selectivity and sensitivity for CO with colorimetric and remarkable fluorescent turn-on signal changes. The detection limit of this probe for CO is as low as 37 nM with a linear range of 0-30 μM. More importantly, this probe (1 μM dose) can be conveniently used for fluorescent imaging CO in living cells.
A general strategy to quantify analytes through fluorescence chromaticity and luminosity
Liang, Tianyu,Yang, Peiwei,Wu, Tianhong,Shi, Menghan,Xu, Xiayu,Qiang, Taotao,Sun, Xiaolong
, p. 2975 - 2979 (2020/07/20)
To realize a fast, easy-operation and precise way using fluorescence probes to quantify analytes is a goal to facilitate detection, especially in situ. Herein, we are reporting an approach which can be generally employed for the differentiation and quanti
Fat mass and obesity-associated protein (FTO) inhibitors prepared from 9-(2-carboxyphenyl) xanthene compounds and therapeutic effects thereof
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Paragraph 0055-0058, (2020/07/13)
The invention relates to usage of the following general formula I as a drug for diseases targeting fat mass and obesity-associated protein (FTO), and provides usage of 9-(2-carboxyphenyl) xanthene compounds in preparation of FTO inhibitors. Specifically, the invention discloses usage of the 9-(2-carboxyphenyl) xanthene compounds as shown in the formula (I), as well as derivatives and pharmaceutically acceptable salts thereof, in preparation of the FTO inhibitors or pharmaceutical compositions for treating FTO-related diseases.
