- 1O2 Generating Luminescent Lanthanide Complexes with 1,8-Naphthalimide-Based Sensitizers
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Lanthanide ion (LnIII) complexes with two new 1,8-naphthalimide-based ligands, Nap-dpe and Nap-cbx, were isolated, and their photophysical properties were explored. Upon excitation at 335 nm, Nap-dpe and Nap-cbx sensitize visible and near-infra
- Johnson, Katherine R.,De Bettencourt-Dias, Ana
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- Azido- and amino-substituted dipicolinates for the sensitization of the luminescent lanthanides EuIII and TbIII
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Dipicolinate-based ligands substituted with azido- or amino- functional groups were synthesized and characterized. Crystal structures of EN3, CN3, CNH2, and ENH2 were obtained, and the ability of these compounds to sensitize LnIII luminescence (LnIII = EuIII and TbIII) was explored. Luminescence efficiencies of EuIII and TbIII were determined and are ?Eu = 0.11%, 0.15%, and 13.8% for [Ln(CN3)3]3+, [Ln(EN3)3]3+, [Ln(CNH2)3]3+, respectively, and ?Tb = 0.30%, 0.27%, and 28.9% for [Ln(CN3)3]3+, [Ln(EN3)3]3+, [Ln(ENH2)3]3+. The highest luminescence efficiencies are ?Eu = 14.4% for [Eu(ENH2)3]3+ and ?Tb = 29.7% for [Tb(CNH2)3]3+. Similar 1S and 3T excited state energies were observed for all ligands and did not explain the observed discrepancies in luminescence efficiency of their TbIII and EuIII complexes. Further analysis revealed that the azido-derivatives were not photostable, which likely contributed to the low luminescence efficiency.
- Johnson, Katherine R.,de Bettencourt-Dias, Ana
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- BODIPY-based hydroxypyridyl derivative as a highly Ni2+-selective fluorescent chemosensor
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A novel fluorescent chemosensor based on BODIPY-NO2 was synthesized and characterized by NMR, MALDI-MS, UV-Vis and fluorescence spectrum. Also, the single-crystal structure of BODIPY-NO2 was determined by X-ray crystallography. The chemosensor shows selective “turn-off” fluorescence response to Ni2+ ion over various other competing metal ions such as Li+, K+, Ca2+, Mg2+, Hg2+, Cu2+, Zn2+, Cd2+ and Mn2+ in CH3CN solution. The BODIPY-NO2 showed a visible absorption band at 502 nm with a shoulder at the shorter wavelength side. The fluorescence emission band was observed at 543 nm of the sensor in the presence of Ni2+ ion with high quantum yield (Φ: 0.39). The square planar [Ni(BODIPY-NO2)(CH3CN)] metal center acts as an efficient quencher for the excited-state based on electron-transfer processes. The BODIPY-NO2 to Ni2+ sensitive nature was determined from the limit of detection 1.7 × 10?7 M in fluorescence emission. The chemosensor BODIPY-NO2 binds to Ni2+ in a 1:1 molar ratio calculated by the job's plot and the binding constant is determined to be 3.1 × 105 M?1. The fluorescence quenching occurred in an acid condition, using the titration experiment with pH 1.0–4.0.
- Chen, Yen-Chun,Devendhiran, Tamiloli,Dong, Teng-Yuan,Huang, Po-Jui,Kumarasamy, Keerthika,Lin, Mei-Ching
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- Luminescent Carbazole-Based EuIII and YbIII Complexes with a High Two-Photon Absorption Cross-Section Enable Viscosity Sensing in the Visible and near IR with One- And Two-Photon Excitation
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The newly synthesized EuIII and YbIII complexes with the new carbazole-based ligands CPAD2- and CPAP4- display the characteristic long-lived metal-centered emission upon one- and two-photon excitation. The EuIII complexes show the expected narrow emission bands in the red region, with emission lifetimes between 0.382 and 1.464 ms and quantum yields between 2.7% and 35.8%, while the YbIII complexes show the expected emission in the NIR region, with emission lifetimes between 0.52 and 37.86 μs and quantum yields between 0.028% and 1.12%. Two-photon absorption cross sections (σ2PA) as high as 857 GM were measured for the two ligands. The complexes showed a strong dependence of the one- and two-photon sensitized emission intensity on solvent viscosity in the range of 0.5-200 cP in the visible and NIR region.
- De Bettencourt-Dias, Ana,Fetto, Natalie R.,Monteiro, Jorge H. S. K.,Tucker, Matthew J.
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supporting information
p. 3193 - 3199
(2020/03/19)
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- An efficient triazole-pyridine-bistetrazolate platform for highly luminescent lanthanide complexes
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Two new triazole-pyridine-bistetrazolate ligands were synthesized via a versatile procedure that allows for further derivatization; their corresponding homoleptic tris-ligand nona-coordinated lanthanide complexes are highly luminescent in the solid state and in a PVA polymeric matrix with measured values for the luminescence quantum yield of 70(7) and 98(9)% for Eu III and TbIII, respectively. This journal is the Partner Organisations 2014.
- Di Pietro,Imbert,Mazzanti
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supporting information
p. 10323 - 10326
(2014/08/18)
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- Development of metal-chelating inhibitors for the Class II fructose 1,6-bisphosphate (FBP) aldolase
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It has long been suggested that the essential and ubiquitous enzyme fructose 1,6-bisphosphate (FBP) aldolase could be a good drug target against bacteria and fungi, since lower organisms possess a metal-dependant (Class II) FBP aldolase, as opposed to higher organisms which possess a Schiff-base forming (Class I) FBP aldolase. We have tested the capacity of derivatives of the metal-chelating compound dipicolinic acid (DPA), as well a thiol-containing compound, to inhibit purified recombinant Class II FBP aldolases from Mycobacterium tuberculosis, Pseudomonas aeruginosa, Bacillus cereus, Bacillus anthracis, and from the Rice Blast causative agent Magnaporthe grisea. The aldolase from M. tuberculosis was the most sensitive to the metal-chelating inhibitors, with an IC50 of 5.2 μM with 2,3- dimercaptopropanesulfonate (DMPS) and 28 μM with DPA. DMPS and the synthesized inhibitor 6-(phosphonomethyl)picolinic acid inhibited the enzyme in a time-dependent, competitive fashion, with second order rate constants of 273 and 270 M- 1 s- 1 respectively for the binding of these compounds to the M. tuberculosis aldolase's active site in the presence of the substrate FBP (KM 27.9 μM). The most potent first generation inhibitors were modeled into the active site of the M. tuberculosis aldolase structure, with results indicating that the metal chelators tested cannot bind the catalytic zinc in a bidentate fashion while it remains in its catalytic location, and that most enzyme-ligand interactions involve the phosphate binding pocket residues.
- Labbe, Genevieve,Krismanich, Anthony P.,De Groot, Sarah,Rasmusson, Timothy,Shang, Muhong,Brown, Matthew D.R.,Dmitrienko, Gary I.,Guillemette, J. Guy
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scheme or table
p. 49 - 58
(2012/09/21)
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- NOVEL JNK INHIBITORS
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Disclosed are compounds of the formula (I) wherein X is N or CH, and Y is N or CR5. Also disclosed are methods of treating JNK and ERK mediated diseases using the compounds of formula 1.0.
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Page/Page column 155
(2008/12/07)
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- Diamino-C,N-diarylpyridine positional isomers as inhibitors of lysophosphatidic acid acyltransferase-β
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2,6-Diamino-4,N-diarylpyridines were identified as potent, isoform selective inhibitors of the enzymatic activity of lysophosphatidic acid acyltransferase-β (LPAAT-β).
- Hong, Feng,Hollenback, David,Singer, Jack W.,Klein, Peter
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p. 4703 - 4707
(2007/10/03)
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- Pyridines and uses thereof
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The invention relates to pyridines and uses thereof, including to inhibit lysophosphatidic acid acyltransferase β (LPAAT-β) activity and/or proliferation of cells such as tumor cells.
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Page/Page column 8
(2008/06/13)
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