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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 …
Effect Of Chirality Of Small Molecule Organofluorine Inhibitors Of Amyloid Self-Assembly On Inhibitor Potency, Abha Sood, Abid Shaikh, Samson Hailemichael, Michelle Foster, Béla Török, Marianna Török
Effect Of Chirality Of Small Molecule Organofluorine Inhibitors Of Amyloid Self-Assembly On Inhibitor Potency, Abha Sood, Abid Shaikh, Samson Hailemichael, Michelle Foster, Béla Török, Marianna Török
Abid Shaikh
The effect of enantiomeric trifluoromethyl-indolyl-acetic acid ethyl esters on the fibrillogenesis of Alzheimer’s amyloid β (Aβ) peptide is described. These compounds have been previously identified as effective inhibitors of the Aβ self-assembly in their racemic form. Thioflavin-T Fluorescence Spectroscopy and Atomic Force Microscopy were applied to assess the potency of the chiral target compounds. Both enantiomers showed significant inhibition in the in vitro assays. The potency of the enantiomeric inhibitors appeared to be very similar to each other suggesting the lack of the stereospecific binding interactions between these small molecule inhibitors and the Aβ peptide.
Triflic Acid Controlled Successive Annelation Of Aromatic Sulfonamides: An Efficient One-Pot Synthesis Of N-Sulfonyl Pyrroles, Indoles And Carbazoles, Abid Shaikh, Liliana Teixeira, Béla Török
Triflic Acid Controlled Successive Annelation Of Aromatic Sulfonamides: An Efficient One-Pot Synthesis Of N-Sulfonyl Pyrroles, Indoles And Carbazoles, Abid Shaikh, Liliana Teixeira, Béla Török
Abid Shaikh
A novel one-pot synthesis of N-substituted heterocycles via successive cyclization/annelation starting from primary sulfonamides is described. This process directly leads to N-sulfonyl pyrroles, indoles and carbazoles. The selection of an appropriate reactant/triflic acid ratio successfully controls the formation of the desired product.
Synthesis Of Trifluoromethyl-Imines By Solid Acid/Superacid Catalyzed Microwave-Assisted Approach, Abid Shaikh, Markku Savolainen, Shainaz M. Landge, Jinbo Hu, G. K. S. Prakash, George A. Olah, Béla Török
Synthesis Of Trifluoromethyl-Imines By Solid Acid/Superacid Catalyzed Microwave-Assisted Approach, Abid Shaikh, Markku Savolainen, Shainaz M. Landge, Jinbo Hu, G. K. S. Prakash, George A. Olah, Béla Török
Abid Shaikh
Trifluoromethyl, Imine, Clay, Solid acids, Solid superacid, Catalysis, Microwave irradiation Abstract: A new solid acid/superacid catalyzed microwave assisted synthesis of trifluoromethyl-imines is described. Various α,α,α-trifluoromethylketones react readily with primary amines to produce the corresponding imines. Two different strategies have been employed; one is the application of microwave irradiation coupled with solvent-free solid acid catalysis. The other method, for highly deactivated substrates includes the use of a pressure vessel at 175 °C temperature, with solid superacid catalysis. Using the solid acid K-10 montmorillonite or the superacidic perfluorinated resinsulfonic acid Nafion-H, a wide variety of trifluoromethylated imines have been synthesized using the …