Design, synthesis and biological activity of 1H-indene-2-carboxamides as multi-targeted anti-Alzheimer agents.

The aim of this study was to design new molecules and evaluate their anticholinesterase and amyloid beta (Aß1-42) inhibition activities as multifunctional drug candidates for the treatment of Alzheimer's disease (AD). A series of 5,6-dimethoxy-1H-indene-2-carboxamides (1-22) was synthesized; cholinesterase inhibitory activities of the compounds were measured according to Ellman's colorimetric assay, while the thioflavin T assay was used for measuring the inhibition of Aß1-42 aggregation. The results revealed that most compounds showed higher inhibitory activity against BuChE than AChE. Compounds 20 and 21 were found to be the most potent BuChE inhibitors with respective IC50 values of 1.08 and 1.09 µM. Compounds 16, 20, 21 and 22 exhibited remarkable inhibition of Aß1-42 aggregation. Kinetic analysis showed that the most potent BuChE inhibitor (20) acted as a noncompetitive inhibitor. Docking studies suggested that inhibitor 20 displayed many potential hydrogen-bondings with the PAS of BuChE. These results suggest that compound 20 may be an especially promising multifunctional drug for the prevention and treatment of AD.

Synthesis of donepezil-based multifunctional agents for the treatment of Alzheimer's disease.

Amyloid beta (Aß) and cholinesterase enzymes (AChE, BuChE) are important biological targets for the effective treatment of Alzheimer's disease. In this study, the aim was to synthesize new donepezil-like secondary amide compounds that display a potent inhibition of cholinesterases and Aß with antioxidant and metal chelation abilities. All test compounds showed activities against both ChEs and ß1-42 inhibition. The most encouraging compound, 20, is an AChE inhibitor with high anti-aggregation activity (55.3%). Based on the results, compound 20 may be a promising structure in further research for new anti-Alzheimer's agents.

Preparation, anticholinesterase activity, and docking study of new 2-butenediamide and oxalamide derivatives.

Several new oxalamide and 2-butenediamide derivatives have been designed, synthesized and evaluated as the acetyl- and butyryl-cholinesterase inhibitors for Alzheimer's disease. The enzyme inhibitory activity of the synthesized compounds was measured using Ellman's colorimetric method. It was revealed that compound 1a (N,N'-bis-(4-chloro-benzyl)-N,N'-diphenyl-oxalamide) showed maximum activity against BuChE with a half maximal inhibitory concentration (IC50) = 1.86 µM and compound 2a (but-2-enedioic acid bis-[(4-chloro-benzyl)-phenyl-amide]) exhibited optimum AChE (IC50 = 1.51 µM) inhibition with a high-selectivity index. To better understand the enzyme-inhibitor interaction of the most active compounds towards cholinesterase, molecular modelling studies were carried out. Docking simulations revealed that inhibitors 1a and 2a targeted both the catalytic active site and the peripheral anionic site of 1ACJ and 1P0I.

Microwave-assisted synthesis, molecular docking, and cholinesterase inhibitory activities of new ethanediamide and 2-butenediamide analogues.

A novel series of meta-substituted ethanediamide and 2-butenediamide derivatives were synthesized and tested for their ability to inhibit electric eel acetylcholinesterase (AChE) and equine serum butyrylcholinesterase (BuChE). The synthesized compounds were evaluated against ChE enzymes using the colorimetric method described by Ellman et al. (Biochem. Pharmacol., 7, 1961). It was revealed that some synthesized compounds exhibited high anticholinesterase activity, among which compounds 1f and 2f were the most active inhibitors against BuChE (IC50 value=1.47 µM) and AChE (IC50 value=2.09 µM), respectively. Docking simulations revealed that the inhibitors 1f and 2f are capable of simultaneously binding the peripheral anionic site as well as the catalytic anionic site of both ChE enzymes. These derivatives are considered interesting candidates for Alzheimer's disease treatment.

Gephyrin selective intrabodies as a new strategy for studying inhibitory receptor clustering.

The microtubule-binding protein gephyrin is known to play a pivotal role in targeting and clustering postsynaptic inhibitory receptors. Here, the Intracellular Antibodies Capture Technology (IATC) was used to select two single-chain antibody fragments or intrabodies, which, fused to nuclear localization signals (NLS), were able to efficiently and selectively remove gephyrin from glycine receptor (GlyR) clusters. Co-transfection of NLS-tagged individual intrabodies with gephyrin-enhanced green fluorescent protein (EGFP) in HEK 293 cells revealed a partial relocalization of gephyrin aggregates onto the nucleus or in the perinuclear area. When expressed in cultured neurons, these intrabodies caused a significant reduction in the number of immunoreactive GlyR clusters, which was associated with a decrease in the peak amplitude of glycine-evoked whole cell currents as assessed with electrophysiological experiments. Hampering protein function at a posttranslational level may represent an attractive alternative for interfering with gephyrin function in a more spatially localized manner.

Molecular characterization of cDNA encoding resistance gene-like sequences in Buchloe dactyloides.

Current knowledge of resistance (R) genes and their use for genetic improvement in buffalograss (Buchloe dactyloides [Nutt.] Engelm.) lag behind most crop plants. This study was conducted to clone and characterize cDNA encoding R gene-like (RGL) sequences in buffalograss. This report is the first to clone and characterize of buffalograss RGLs. Degenerate primers designed from the conserved motifs of known R genes were used to amplify RGLs and fragments of expected size were isolated and cloned. Sequence analysis of cDNA clones and analysis of putative translation products revealed that most encoded amino acid sequences shared the similar conserved motifs found in the cloned plant disease resistance genes RPS2, MLA6, L6, RPM1, and Xa1. These results indicated diversity of the R gene candidate sequences in buffalograss. Analysis of 5' rapid amplification of cDNA ends (RACE), applied to investigate upstream of RGLs, indicated that regulatory sequences such as TATA box were conserved among the RGLs identified. The cloned RGL in this study will further enhance our knowledge on organization, function, and evolution of R gene family in buffalograss. With the sequences of the primers and sizes of the markers provided, these RGL markers are readily available for use in a genomics-assisted selection in buffalograss.