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Full-Text Articles in Physical Sciences and Mathematics
Disassembly Of Preformed Amyloid Ss Fibrils By Small Organofluorine Molecules, Abha Sood, Abid Shaikh, Catharine Sauer, Samson Hailemichael, Michelle Foster, Béla Török, Marianna Török
Disassembly Of Preformed Amyloid Ss Fibrils By Small Organofluorine Molecules, Abha Sood, Abid Shaikh, Catharine Sauer, Samson Hailemichael, Michelle Foster, Béla Török, Marianna Török
Abid Shaikh
A potential therapeutic approach for Alzheimer’s disease is to reduce the amount of toxic amyloid-beta oligomers and fibrillar amyloid plaques. In order to contribute to this approach the ability of small organofluorine compounds that were previously reported as successful inhibitors of fibrillogenesis to destabilize preformed fibrils of the amyloid-beta peptide was studied. These organofluorine molecules including chiral compounds were tested in vitro using standard methods based on Thioflavin-T (THT) fluorescence spectroscopy, atomic force microscopy (AFM) and Fourier-transform infrared spectroscopy (FTIR). It was observed that 5′-halogen substituted 3,3,3-trifluoromethyl-2-hydroxyl-(indol-3-yl)-propionic acid esters showed significant activity in the disassembly of the preformed fibrils. Since …
Speciation, Luminescence, And Alkaline Fluorescence Quenching Of 4-(2-Methylbutyl)Aminodipicolinic Acid (H2mebadpa), Gilles Muller, A. J. Ingram, A. G. Dunpal, R. Dipietro
Speciation, Luminescence, And Alkaline Fluorescence Quenching Of 4-(2-Methylbutyl)Aminodipicolinic Acid (H2mebadpa), Gilles Muller, A. J. Ingram, A. G. Dunpal, R. Dipietro
Faculty Publications, Chemistry
4-(2-Methylbutyl)aminodipicolinic acid (H2MEBADPA) has been synthesized and fully characterized in terms of aqueous phase protonation constants (pKa's) and photophysical measurements. The pKa's were determined by spectrophotometric titrations, utilizing a fully sealed titration system. Photophysical measurements consisted of room temperature fluorescence and frozen solution phosphorescence as well as quantum yield determinations at various pH, which showed that only fully deprotonated MEBADPA2– is appreciably emissive. The fluorescence of MEBADPA2– has been determined to be quenched by hydroxide and methoxide anions, most likely through base-catalyzed excited-state tautomerism or proton transfer. This quenching phenomenon has been quantitatively explored through steady-state and time-resolved fluorescence measurements. …
Speciation, Luminescence, And Alkaline Fluorescence Quenching Of 4-(2-Methylbutyl)Aminodipicolinic Acid (H2mebadpa), Gilles Muller, A. J. Ingram, A. G. Dunpal, R. Dipietro
Speciation, Luminescence, And Alkaline Fluorescence Quenching Of 4-(2-Methylbutyl)Aminodipicolinic Acid (H2mebadpa), Gilles Muller, A. J. Ingram, A. G. Dunpal, R. Dipietro
Gilles Muller
4-(2-Methylbutyl)aminodipicolinic acid (H2MEBADPA) has been synthesized and fully characterized in terms of aqueous phase protonation constants (pKa's) and photophysical measurements. The pKa's were determined by spectrophotometric titrations, utilizing a fully sealed titration system. Photophysical measurements consisted of room temperature fluorescence and frozen solution phosphorescence as well as quantum yield determinations at various pH, which showed that only fully deprotonated MEBADPA2– is appreciably emissive. The fluorescence of MEBADPA2– has been determined to be quenched by hydroxide and methoxide anions, most likely through base-catalyzed excited-state tautomerism or proton transfer. This quenching phenomenon has been quantitatively explored through steady-state and time-resolved fluorescence measurements. …
Heterogeneity Of Reaction Rates In An Ionic Liquid: Quantitative Results From 2d- Muppets, Kalyanasis Sahu, Sean Kern, Mark Berg
Heterogeneity Of Reaction Rates In An Ionic Liquid: Quantitative Results From 2d- Muppets, Kalyanasis Sahu, Sean Kern, Mark Berg
Sean J. Kern
The hypotheses that ionic liquids are structurally heterogeneous at the molecular level and, even further, that this heterogeneity can transfer to the rates of reactions run in ionic liquids is being actively debated. Here, this hypothesis is tested using multiple population-period transient spectroscopy (MUPPETS), an emerging type of multidimensional measurement that resolves the kinetics of subensembles within a heterogeneous sample. A previous MUPPETS study of the excited-state twisting and electronic relaxation of auramine indicated that an ionic-liquid solvent induces rate dispersion due to a combination of heterogeneous and homogeneous processes, but those data could not quantitatively separate these contributions [Khurmi, …
A New Acridine-Imidazolium-Based Cholestane Receptor For Anion Sensing, Jyoti Ramesh Jadhav, Md Wasi Ahmad, Hong Seok Kim
A New Acridine-Imidazolium-Based Cholestane Receptor For Anion Sensing, Jyoti Ramesh Jadhav, Md Wasi Ahmad, Hong Seok Kim
Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)
A new highly selective receptor (3) based on an acridine-imidazolium functionalized cholestane for anion sensing was designed and synthesized. A binding study of 3 with various anions was assessed by UV-vis and fluorescence spectroscopies in dry CH3CN. Receptor 3 showed the highest selectivity toward hydrogen pyrophosphate.
Pyrenyl-Appended Imidazolium Receptor For Selective Fluorescence Sensing Of Oxalic Acid, Md Wasi Ahmad, Sung Hong Kim, Hong Seok Kim
Pyrenyl-Appended Imidazolium Receptor For Selective Fluorescence Sensing Of Oxalic Acid, Md Wasi Ahmad, Sung Hong Kim, Hong Seok Kim
Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)
A new fluorescent imidazolium-based cholestane receptor 4 bearing a pyrene moiety was synthesized. The binding ability of 4 toward various dicarboxylic acids was examined by UV–vis and fluorescence spectroscopy. Receptor 4 showed the highest binding constant for oxalic acid among all the tested dicarboxylic acids. Oxalic acid formed a complex with 4 with a 1:2 ratio in ethanol.
Ticl(Oipr)3-Mediated One-Pot Reductive Amination Of 1,1'-Diacetylferrocene With Aryl Amines, Md Wasi Ahmad, Sang Yeon Lee, Tae Jeong Kim, Hong Seok Kim
Ticl(Oipr)3-Mediated One-Pot Reductive Amination Of 1,1'-Diacetylferrocene With Aryl Amines, Md Wasi Ahmad, Sang Yeon Lee, Tae Jeong Kim, Hong Seok Kim
Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)
No abstract provided.