26093-31-2Relevant articles and documents
HgII-selective fluorescent indicator: One-step synthesis
Kim, Seul-Bi,Cho, Dong-Gyu
, p. 2495 - 2498 (2012)
Fluorescent indicator 2 was synthesized by a single-step reaction. The indicator underwent an HgII-selective reaction (hydrolysis/ decarboxylation sequence) in the presence of HgII, which was verified by using LC-MS and NMR techniques.
Application of 2D-fluorescence spectroscopy for on-line monitoring of pseudoenantiomeric transformations in supercritical carbon dioxide systems
Knuettel, Torsten,Meyer, Hartmut,Scheper, Thomas
, p. 6184 - 6189 (2005)
2D-Fluorescence spectroscopy has been shown to be effective for the on-line monitoring of spectroscopic detectable substrates L-phenylalanine-7-amido-4- methylcoumarine (L-PheAMC) and D-phenylalanine-7-amido-4- trifluoromethylcoumarine (D-PheAFC) in supercritical carbon dioxide. Earlier investigations with the coumarine substrates in watery and organic phases showed their potential for on-line enantiomeric evaluations of enzymatic reactions in different reaction media. The solubility of the different substrates and their fluorescence maximums were investigated in SCCO2. The sole hydrolyzations of L-PheAMC and D-PheAFC with α-chymotrypsin and the esterase from porcine liver were tracked on-line in the supercritical medium; however, different solubility characteristics of the methyl- and trifluoromethyl-substituted coumarins influence the simultaneous detection of the L- and D-substrate within the applied high-pressure reactor system.
Coumarin-coupled receptor as a membrane-permeable, Cu2+- selective fluorescent chemosensor for imaging copper(II) in HEPG-2 cell
Wang, Mao-Xiang,Huang, Sheng-Hai,Meng, Xiang-Ming,Zhu, Man-Zhou,Guo, Qing-Xiang
, p. 462 - 465 (2008)
A novel fluorescent chemosensor 1 for imaging labile Cu2+ in living biological samples was designed and synthesized; it exhibits very strong fluorescence responses to Cu2+, and its LSM images strongly support the existence of Cu2+ in HEGP-2 cell. Copyright
Synthesis of Novel and Thermally Stable Water Insoluble Coumarin-based Azo Dyes via a Mild and Green Procedure
Kiani, Mahtab,Karami, Bahador
, p. 756 - 760 (2015)
A series of novel azo coumarin dyes were synthesized by the diazotization of 7-amino coumarins in the presence of catalytic amounts of tungstate sulfuric acid (TSA) followed by coupling with phenol derivatives. Tungstate sulfuric acid catalyzes this reaction at room temperature and short reaction time with high yields. A series of novel azo coumarin dyes were synthesized by the diazotization of 7-amino coumarins in the presence of catalytic amounts of tungstate sulfuric acid (TSA) followed by coupling with phenol derivatives. Tungstate sulfuric acid catalyzes this reaction at room temperature and short reaction time with high yields.
Organic azide inhibitors of cysteine proteases
Le, Giang Thanh,Abbenante, Giovanni,Madala, Praveen K.,Hoang, Huy N.,Fairlie, David P.
, p. 12396 - 12397 (2006)
Cysteine proteases are crucial regulatory enzymes in human physiology and disease. Inhibitors are usually designed with reactive electrophiles to covalently bond to the catalytic cysteinyl sulfur, and consequently they also indiscriminately interact with biological thiolates and other nucleophiles, leading to toxic side effects in vivo. Here we describe an alternative to using reactive electrophiles, demonstrating the use of a much less reactive azidomethylene substituent (-CH2-N3) that confers potent inhibition of cysteine proteases. This new approach resulted in potent, reversible, competitive inhibitors of caspase-1 (IC50 10 nM), with significant advantages over aldehydes such as high stability in vitro to thiols (10 mM dithiothreitol (pH 7.2), 20 mM glutathione (pH 7.2, 9, 11)) and aqueous media, as well as some highly desirable druglike features. It was also demonstrated that azides can be incorporated into inhibitors of other caspases (e.g. 3, 8) and cathepsins (e.g. K, S, B), indicating the versatility of this valuable new approach to cysteine protease inhibition. Copyright
Natural biflavones as?novel inhibitors of?cathepsin B and?K
Zeng,Pan,Tan,Xiong,Zhang
, p. 1247 - 1252 (2006)
Cathepsin B and K, two important members in lysosomal proteases, involve in many serious human diseases, such as tumor and osteoporosis. In order to find their novel inhibitors, we performed the inhibition assays of cathepsin B and cathepsin K in vitro, randomly screened compounds from plants, and found six biflavones, named AMF1-5 and HIF, can potently inhibit cathepsin B and cathepsin K, especially AMF4 and HIF with IC50 of 0.62 and 0.58?μM against cathepsin B. They are novel inhibitors for cathepsin B and K. Inhibition and flexible docking studies indicated that these biflavones are reversible inhibitors of cathepsin B, and their binding patterns and interaction modes with cathepsin B made them more specific to cathepsin B endopeptidase.
A fluorescent assay suitable for inhibitor screening and vanin tissue quantification
Ruan, Benfang H.,Cole, Derek C.,Wu, Paul,Quazi, Amira,Page, Karen,Wright, Jill F.,Huang, Nelson,Stock, Joseph R.,Nocka, Karl,Aulabaugh, Ann,Krykbaev, Rustem,Fitz, Lori J.,Wolfman, Neil M.,Fleming, Margaret L.
, p. 284 - 292 (2010)
Vanin-1 is a pantetheinase that catalyzes the hydrolysis of pantetheine to produce pantothenic acid (vitamin B5) and cysteamine. Reported here is a highly sensitive fluorescent assay using a novel fluorescently labeled pantothenate derivative. The assay has been used for characterization of a soluble version of human vanin-1 recombinant protein, identification and characterization of hits from high-throughput screening (HTS), and quantification of vanin pantothenase activity in cell lines and tissues. Under optimized assay conditions, we quantified vanin pantothenase activity in tissue lysate and found low activity in lung and liver but high activity in kidney. We demonstrated that the purified recombinant vanin-1 consisting of the extracellular portion without the glycosylphosphatidylinositol (GPI) linker was highly active with an apparent Km of 28 μM for pantothenate-7-amino-4-methylcoumarin (pantothenate-AMC), which was converted to pantothenic acid and AMC based on liquid chromatography-mass spectrometry (LC-MS) analysis. The assay also performed well in a 384-well microplate format under initial rate conditions (10% conversion) with a signal-to-background ratio (S/B) of 7 and a Z factor of 0.75. Preliminary screening of a library of 1280 pharmaceutically active compounds identified inhibitors with novel chemical scaffolds. This assay will be a powerful tool for target validation and drug lead identification and characterization.
Purification and characterization of a cathepsin L-like enzyme from the body wall of the sea cucumber Stichopus japonicus
Zhu, Bei-Wei,Zhao, Lu-Lu,Sun, Li-Ming,Li, Dong-Mei,Murata, Yoshiyuki,Yu, Lei,Zhang, Lei
, p. 1430 - 1437 (2008)
Cathepsin L-like enzyme was purified from the body wall of the sea cucumber Stichopus japonicus by an integral method involving ammonium sulfate precipitation and a series of column chromatographies on DEAE Sepharose CL-6B, Sephadex G-75, and TSK-GEL. The molecular mass of the purified enzyme was estimated to be 63 kDa by SDS-PAGE. The enzyme cleaved N-carbobenzoxy- phenylalanine-arginine 7-amido-4-methylcoumarin with Km (69.92 μM) and kcat (12.80/S) hardly hydrolyzed N-carbobenzoxy-arginine- arginine 7-amido-4-methylcoumarin and L-arginine 7-amido-4-methylcoumarin. The optimum pH and temperature for the purified enzyme were found to be 5.0 and 50°C. It showed thermal stability below 40°C. The activity was inhibited by sulfhydryl reagents and activated by reducing agents. These results suggest that the purified enzyme was a cathepsin L-like enzyme and that it existed in the form of its enzyme-inhibitor complex or precursor.
New ambipolar blue emitting materials based on amino coumarin derivatives with high efficiency for organic lightemitting diodes
Kim, Seungho,Lee, Kyung Jin,Kim, Beomjin,Lee, Jaehyun,Kay, Kwang-Yol,Park, Jongwook
, p. 8020 - 8024 (2013)
New blue emitting materials, 7-diphenylamino-4-methyl-coumarin (DPA-MC) and aminotri( 4-methylcoumarin) (T-MC) including coumarin moiety were synthesized by Ullman reaction. Optical and electronic properties were examined by UV-Vis. Absorption spectrum, PL spectrum, and cyclic voltammetry. UV-Vis. spectra of DPA-MC and T-MC in a film state showed maximum absorption wavelengths of 382 nm and 399 nm, respectively. PL spectra of DPA-MC and T-MC show maximum emission wavelengths of 463 nm and 481 nm respectively. Non-doped OLED devices were fabricated by using the synthesized materials as an emitting material layer. DPA-MC compound showed highly efficient luminescence properties. EL spectrum of DPA-MC exhibited a maximum value of 463 nm and DPA-MC device provided luminescence efficiency of 3.83 cd/A, power efficiency of 2.46 lm/W, external quantum efficiency of 3.71% and CIE coordinates of (0.154, 0.190) at a current density of 10 mA/cm2. In particular, Power efficiency increased by more than 1.6 times in DPA-MC (2.46 lm/W), which is higher than commercialized material, DPVBi (1.46 lm/W). High EL performance might come from ambipolar effects of a molecular structure. Copyright
Polymersome Popping by Light-Induced Osmotic Shock under Temporal, Spatial, and Spectral Control
Peyret, Ariane,Ibarboure, Emmanuel,Tron, Arnaud,Beauté, Louis,Rust, Ruben,Sandre, Olivier,McClenaghan, Nathan D.,Lecommandoux, Sebastien
, p. 1566 - 1570 (2017)
The light-triggered, programmable rupture of cell-sized vesicles is described, with particular emphasis on self-assembled polymersome capsules. The mechanism involves a hypotonic osmotic imbalance created by the accumulation of photogenerated species inside the lumen, which cannot be compensated owing to the low water permeability of the membrane. This simple and versatile mechanism can be adapted to a wealth of hydrosoluble molecules, which are either able to generate reactive oxygen species or undergo photocleavage. Ultimately, in a multi-compartmentalized and cell-like system, the possibility to selectively burst polymersomes with high specificity and temporal precision and to consequently deliver small encapsulated vesicles (both polymersomes and liposomes) is demonstrated.
