Dual Acetylcholinesterase Research Articles

Assessing indole derivative molecules as dual acetylcholinesterase and butyrylcholinesterase inhibitors through In Vitro inhibition and molecular modelling studies

Alzheimer's Disease (AD) is the most common type of dementia that develops with age, threatens the quality of life, is increases in number around the world, and has no effective treatment. The most important therapeutic targets in drug development studies for the treatment of AD are acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors. The inadequacy of existing AChE and BChE inhibitors in the treatment of AD has led to the need to identify new AChE/BChE inhibitors with fewer side effects. In this study, considering the pharmacological importance indole derivatives, inhibition effects of some indole derivative molecules (a-e) on AChE and BChE activity were investigated. IC50 values of a-e against AChE were found to be 0.480 µM, 1.682 µM, 0.916 µM, 1.093 µM, 0.340 µM, respectively. On the other hand, IC50 values of compounds a-e on BChE activity were determined as 2.18 µM, 4.49 µM, 2.28 µM, 6.36 µM, 1.940 µM, respectively. As a result, it was seen that indole derivatives (a-e) showed strong inhibition effect on both enzymes. Additionally, these inhibition results were supported by molecular modelling studies. As a conclusion, results of this study will contribute to studies on the synthesis of new indole-derived AChE and BChE inhibitors for the treatment of AD.

Discovery of novel dual acetylcholinesterase and butyrylcholinesterase inhibitors using machine learning and structure-based drug design

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) are crucial targets that catalyse the breakdown of acetylcholine (ACh) and are implicated in the pathogenesis of Alzheimer's disease (AD). Thus, the development of cholinesterase (AChE and BChE) inhibitors with a novel scaffold is an effective way to intervene in the pathogenesis of AD. This study used a multistep virtual screening method combined with machine learning (ML) models and structural bioinformatics to identify a novel dual acetylcholinesterase and butyrylcholinesterase inhibitor from the Maybridge database. Finally, five common hits (AW00462, AW00794, MWP01235, SCR00709, CD05692) were found after a consensus analysis of classification models and multistep screening protocol which showed their potential against AChE and BChE enzymes. Further, MM/GBSA free energy calculation and MD simulation studies predicted CD05692 as a potential inhibitor, which formed stable interactions with the active site residues compared with the other compounds. The docking score of CD05692 was found maximum negative (AChE= -15.03 Kcal/mole; BChE= -7.07 Kcal/mole) compared with the other identified hits. The MM/GBSA binding free energy ∆G (AChE= -76.34 Kcal/mole; BChE= -74.72 Kcal/mole) and the HOMO orbital energy (-0.352,410 eV) was also predicted to be in favour of CD05692. The in silico pharmacokinetic investigations also ascertained its drug likeliness properties. Finally, compound CD05692 was synthesised, characterized and evaluated in vitro for ChE (hAChE and hBChE) inhibitory potential. The IC50 value of the lead CD05692 has shown good hAChE inhibition (IC50 = 0.927 ± 0.019 µM) and moderate hBChE inhibition (IC50 = 6.377 ± 0.038 µM). Thus, based on this study, we proposed that CD05692 could further be optimized as a lead to design potential cholinesterase inhibitors to combat AD.

Design, synthesis, and structure-activity relationship of caffeine-based triazoles as dual AChE and BACE-1 inhibitors.

Natural products have significantly contributed to drug discovery for neurodegenerative diseases. Caffeine is one of the well-known central nervous system(CNS)-active natural products. Besides its CNS stimulant properties, it is a mild inhibitor of acetylcholinesterase (AChE) and possesses memory-enhancing properties. The present work aimed to improve the AChE inhibition activity of the caffeine. The rationally designed caffeine-based triazoles were synthesized and evaluated in vitro for cholinesterase and β-site amyloid precursor protein cleaving enzyme-1 (BACE-1) inhibitory activities. The attachment of triazole to the caffeine enhances its AChE inhibition activity from half-maximal inhibitory concentration (IC50 ) of 129 µMto0.49 µM (derivative, 6l). The caffeine core interacts with the peripheral anionic site, whereas the benzyl triazole occupies the catalytic anionic site located at the bottom of the active site gorge. The structure-activity relationship revealed that the four-atom ester linker is superior to shorter linkers for connecting the caffeine core to the triazole. The 2,6-difluorobenzyl triazole-linked caffeine derivative, 6d, exhibits dual inhibition of AChE and BACE-1 with IC50 values of 1.43 and 10.9 µM, respectively. The derivative 6d inhibits AChE via a mixed-type mode with an inhibition rate constant(Ki ) value of 2.35 μM, which was corroborated by docking studies. The triazole 6d has an acceptable stability profile in human liver microsomes (t1/2 = 54 min) and was found to possessCNS permeabilitywhen evaluated using the parallel artificial membrane permeability blood-brain barrier assay. The results presented herein warrant investigating caffeine-based triazoles in preclinical models of Alzheimer's disease.

Synthesis of novel thiosemicarbazone derivatives and investigation of their dual AChE and MAO-B inhibitor effects.

In this study, 15 thiosemicarbazone derivatives were synthesized. Analysis of the obtained compounds was performed by means of 1 H-NMR, 13 C-NMR and high resolution mass spectroscopy (HRMS) spectroscopic methods. The inhibition effect of the obtained compounds on cholinesterase and monoaminoxidase (MAO) enzymes were investigated with in vitro methods. None of the compounds showed significant activity on the butyrylcholinesterase enzyme. On the other hand, compounds 3b, 3c, 3e, 3k, 3l, 3m, 3n and 3o displayed significant activity on acetylcholinesterase (AChE) while compounds 3f, 3i, 3k, 3l, 3m, 3n, 3o also showed remarkable effects on monoamine oxidase-B (MAO-B) enzymes. For the selected compounds, docking studies were performed and the enzyme active site and binding modes were determined. It was revealed that the strongest interaction with AChE and MAO-B enzyme active sites was observed with the compound 3k. Another important factor in the treatment of diseases affecting the central nervous system such as Alzheimer's is the ability of the compounds to cross the blood-brain barrier (BBB). Additionally, the agents planned for the treatment of these diseases must also pass the blood-brain barrier. Therefore, in silico BBB penetration properties of active compounds were investigated.

Multiadducts of C60 Modulate Amyloid-β Fibrillation with Dual Acetylcholinesterase Inhibition and Antioxidant Properties: In Vitro and In Silico Studies.

Amyloid-β (Aβ) fibrils induce cognitive impairment and neuronal loss, leading to onset of Alzheimer's disease (AD). The inhibition of Aβ aggregation has been proposed as a therapeutic strategy for AD. Pristine C60 has shown the capacity to interact with the Aβ peptide and interfere with fibril formation but induces significant toxic effects in vitro and in vivo. To evaluate the potential of a series of C60 multiadducts to inhibit the Aβ fibrillization. A series of C60 multiadducts with four to six diethyl malonyl and their corresponding disodium-malonyl substituents were synthesized as individual isomers. Their potential on Aβ fibrillization inhibition was evaluated in vitro, in cellulo, and silico. Antioxidant activity, acetylcholinesterase inhibition capacity, and toxicity were assessed in vitro. The multiadducts modulate Aβ fibrils formation without inducing cell toxicity, and that the number and polarity of the substituents play a significant role in the adducts efficacy to modulate Aβ aggregation. The molecular mechanism of fullerene-Aβ interaction and modulation was identified. Furthermore, the fullerene derivatives exhibited antioxidant capacity and reduction of acetylcholinesterase activity. Multiadducts of C60 are novel multi-target-directed ligand molecules that could hold considerable promise as the starting point for the development of AD therapies.

Novel Sunifiram-carbamate hybrids as potential dual acetylcholinesterase inhibitor and NMDAR co-agonist: simulation-guided analogue design and pharmacological screening

An efficient method for synthesising NMDAR co-agonist Sunifiram (DM235), in addition to Sunifram-carbamate and anthranilamide hybrids, has been developed in high yields via protecting group-free stepwise unsymmetric diacylation of piperazine using N-acylbenzotiazole. Compounds 3f, 3d, and 3i exhibited promising nootropic activity by enhancing acetylecholine (ACh) release in A549 cell line. Moreover, the carbamate hybrid 3f was found to exhibit higher in vitro potency than donepezil with IC50 = 18 ± 0.2 nM, 29.9 ± 0.15 nM for 3f and donepezil, respectively. 3f was also found to effectively inhibit AChE activity in rat brain (AChE = 1.266 ng/mL) compared to tacrine (AChE = 1.137 ng/ml). An assessment of the ADMET properties revealed that compounds 3f, 3d, and 3i are drug-like and can penetrate blood–brain barrier. Findings presented here showcase highly potential cholinergic agents, with expected partial agonist activity towards glycine binding pocket of NMDAR which could lead to development and optimisation of novel nootropic drugs.

Synthesis of novel benzothiazole derivatives and investigation of their enzyme inhibitory effects against Alzheimer's disease.

The use of dual acetylcholinesterase (AChE)–monoamine oxidase B (MAO-B) inhibitors is a new approach in the treatment of Alzheimer disease (AD). In this work, 14 new benzothiazoles (4a–4n) were designed and synthesized. In biological activity studies, the AChE, butyrylcholinesterase (BChE), MAO-A and MAO-B inhibitory potentials of all compounds were evaluated using the in vitro fluorometric method. Additionally, amyloid beta (Aβ)-aggregation inhibitory effects of active compounds were evaluated by means of an in vitro kit-based method. The biological evaluation showed that compounds 4a, 4d, 4f, 4h, 4k and 4m displayed significant activity against AChE and MAO-B enzymes. Compound 4f displayed inhibitory activity against AChE and MAO-B enzyme with IC50 values of 23.4 ± 1.1 nM and 40.3 ± 1.7 nM, respectively. It has been revealed that compound 4f may have the potential to inhibit AChE and MAO-B enzymes, as well as the ability to prevent the formation of beta amyloid plaques accumulated in the brains of patients suffering from AD. In silico studies also support the obtained biological activity findings. Compound 4f provided strong interactions with the active site of both enzymes. In particular, the interaction of compound 4f with flavin adenine dinucleotide (FAD) in the MAO-B enzyme active site is a promising and exciting finding.

Tailored Modeling of Rivastigmine Derivatives as Dual Acetylcholinesterase and Butyrylcholinesterase Inhibitors for Alzheimer's Disease Treatment.

Rational modification of known drug candidates to design more potent ones using computational methods has found application in drug design, development, and discovery. Herein, we integrate computational and theoretical methodologies to unveil rivastigmine derivatives as dual inhibitors of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) for Alzheimer's disease (AD) management. The investigation entails pharmacokinetics screening, density functional theory (DFT) mechanistic study, molecular docking, and molecular dynamics (MD) simulation. We designed over 20 rivastigmine substituents, subject them to some analyses, and identified RL2 with an appreciable blood-brain barrier score and no permeability glycoprotein binding. The compound shows higher acylation energy and a favored binding affinity to the cholinesterase enzymes. RL2 interacts with the AChE and BuChE active sites showing values of -41.1/-39.5 kcal mol-1 while rivastigmine binds with -32.7/-30.7 kcal mol-1 for these enzymes. The study revealed RL2 (4-fluorophenyl rivastigmine) as a potential dual inhibitor for AChE and BuChE towards Alzheimer's disorder management.

Development of Novel Potential Pleiotropic Compounds of Interest in Alzheimer's Disease Treatment through Rigidification Strategy.

The development of Multi-Target Directed Ligand is of clear interest for the treatment of multifactorial pathology such as Alzheimer’s disease (AD). In this context, acetylcholinesterase (AChE) inhibitors have been modulated in order to generate novel pleiotropic compounds targeting a second protein of therapeutic interest in AD. Among them, donecopride was the first example of a dual acetylcholinesterase inhibitor and 5-HT4 receptor agonist. In order to explore the structural diversity around this preclinical candidate we have explored the preparation of novel constrained analogs through late-stage rigidification strategy. A series of phenylpyrazoles was prepared in a late-stage functionalization process and all compounds were evaluated in vitro towards AChE and 5-HTRs. A docking study was performed in order to better explain the observed SAR towards AChE, 5-HT4R and 5-HT6R and this study led to the description of novel ligand targeting both AChE and 5-HT6R.

Design, synthesis and biological assessment of new 1-benzyl-4-((4-oxoquinazolin-3(4H)-yl)methyl) pyridin-1-ium derivatives (BOPs) as potential dual inhibitors of acetylcholinesterase and butyrylcholinesterase

Alzheimer's disease (AD), is among the most growing neurodegenerative diseases, which is mainly caused by the acetylcholine neurotransmitter loss in the hippocampus and cortex. Emerging of the dual Acetylcholinesterase (AChE)/Butyrylcholinesterase (BuChE) inhibitors has increased for treating Alzheimer disease. In this study, we would like to report the design and synthesis of a new sequence of 1-benzyl-4-((4-oxoquinazolin-3(4H)-yl)methyl) pyridin-1-ium derivatives (BOPs) assessed as BuChE and AChE inhibitors. Ellman's approach was used for the evaluation of AChE and BuChE inhibitory activities. Moreover, docking research was conducted to predict the action mechanism. Among all synthesized compounds, 1-(3-bromobenzyl)-3-((4-oxoquinazolin-3(4H)-yl)methyl) pyridin-1-ium bromide (BOP-1) was found to be the most active compound with dual activity for inhibition of AChE (IC50 = 5.90 ± 0.07μM), and BuChE (IC50 = 6.76 ± 0.04μM) and 1-(4-chlorobenzyl)-3-((6,7-dimethoxy-4-oxoquinazolin-3(4H)-yl)methyl) pyridin-1-ium chloride (BOP-8) showed the highest AChE inhibitory activity (IC50s = 1.11 ± 0.09 μM). The synthesized compounds BOP-1 and BOP-8 could be proposed as valuable lead compounds for further drug discovery development against AD.

Design and Development of Cholinesterase Dual Inhibitors towards Alzheimer's Disease Treatment: A Focus on Recent Contributions from Computational and Theoretical Perspective

AbstractIn recent times, review topics on Alzheimer's disease (AD) have received massive attention, especially on drug design and development of potent inhibitors targeting specific pathway(s) of this multifaceted disease. Drug design and development through the use of computer has taken an intriguing dimension over the last two decades, and AD drug design is not an exception. Computational approaches have found usage in identifying potentially active molecules targeting specific enzyme or gene in the pathological pathway of a disease such as AD. Herein, we present an overview of research contributions over the last ten years from different authors who had used computational approaches to explore potent dual inhibitors of the cholinesterase enzymes linked with AD pathogenesis. We gave an introductory background of the disease, highlight challenges of in silico approach to drug design, and discuss its pros and cons. The overview also covers previously reported review works which are related to the topic. We proposed that continued research efforts to unravel more effective dual acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) inhibitors through computational tools could plausibly be a successful approach to AD cure. Computational researchers should leverage on the available cost‐effective resources to identify lead compounds and work in collaboration with experimental personnel to push their discovery forward.

Synthesis, in vitro evaluation and molecular docking of a new class of indolylpropyl benzamidopiperazines as dual AChE and SERT ligands for Alzheimer’s disease

During the last decade, the one drug-one target strategy has resulted to be inefficient in facing diseases with complex ethiology like Alzheimer’s disease and many others. In this context, the multitarget paradigm has emerged as a promising strategy. Based on this consideration, we aim to develop novel molecules as promiscuous ligands acting in two or more targets at the same time. For such purpose, a new series of indolylpropyl-piperazinyl oxoethyl-benzamido piperazines were synthesized and evaluated as multitarget-directed drugs for the serotonin transporter (SERT) and acetylcholinesterase (AChE). The ability to decrease β-amyloid levels as well as cell toxicity of all compounds were also measured. In vitro results showed that at least four compounds displayed promising activity against SERT and AChE. Compounds 18 and 19 (IC50 = 3.4 and 3.6 μM respectively) exhibited AChE inhibition profile in the same order of magnitude as donepezil (DPZ, IC50 = 2.17 μM), also displaying nanomolar affinity in SERT. Moreover, compounds 17 and 24 displayed high SERT affinities (IC50 = 9.2 and 1.9 nM respectively) similar to the antidepressant citalopram, and significant micromolar AChE activity at the same time. All the bioactive compounds showed a low toxicity profile in the range of concentrations studied. Molecular docking allowed us to rationalize the binding mode of the synthesized compounds in both targets. In addition, we also show that compounds 11 and 25 exhibit significant β-amyloid lowering activity in a cell-based assay, 11 (50% inhibition, 10 μM) and 25 (35% inhibition, 10 μM).These results suggest that indolylpropyl benzamidopiperazines based compounds constitute promising leads for a multitargeted approach for Alzheimer’s disease.

N-alkylpiperidine carbamates as potential anti-Alzheimer’s agents

Compounds capable of interacting with single or multiple targets involved in Alzheimer’s disease (AD) pathogenesis are potential anti-Alzheimer’s agents. In our aim to develop new anti-Alzheimer’s agents, a series of 36 new N-alkylpiperidine carbamates was designed, synthesized and evaluated for the inhibition of cholinesterases [acetylcholinesterase (AChE) and butyrylcholinesterase (BChE)] and monoamine oxidases [monoamine oxidase A (MAO-A and monoamine oxidase B (MAO-B)]. Four compounds are very promising: multiple AChE (IC50 = 7.31 μM), BChE (IC50 = 0.56 μM) and MAO-B (IC50 = 26.1 μM) inhibitor 10, dual AChE (IC50 = 2.25 μM) and BChE (IC50 = 0.81 μM) inhibitor 22, selective BChE (IC50 = 0.06 μM) inhibitor 13, and selective MAO-B (IC50 = 0.18 μM) inhibitor 16. Results of enzyme kinetics experiments showed that despite the carbamate group in the structure, compounds 10, 13, and 22 are reversible and non-time-dependent inhibitors of AChE and/or BChE. The resolved crystal structure of the complex of BChE with compound 13 confirmed the non-covalent mechanism of inhibition. Additionally, N-propargylpiperidine 16 is an irreversible and time-dependent inhibitor of MAO-B, while N-benzylpiperidine 10 is reversible. Additionally, compounds 10, 13, 16, and 22 should be able to cross the blood-brain barrier and are not cytotoxic to human neuronal-like SH-SY5Y and liver HepG2 cells. Finally, compounds 10 and 16 also prevent amyloid β1–42 (Aβ1–42)-induced neuronal cell death. The neuroprotective effects of compound 16 could be the result of its Aβ1–42 anti-aggregation effects.

Design, Synthesis and Insecticide Activity of Novel Acetylcholinesterase Inhibitors: Triazolinone and Phthalimide Heterodimers.

Based on the "cluster effect" and the structure characters of acetylcholinesterase (AChE; EC 3.1.1.7), a new series of 1,2,4-triazolin-3-one and phthalimide heterodimers were designed, synthesized, and evaluated as potent dual acetylcholinesterase inhibitors (AChEIs). Most of the synthesized compounds showed good in vitro inhibitory activities towards both Drosophila melanogaster acetylcholinesterase (DmAChE) and Musca domestica acetylcholinesterase (MdAChE). Among them, 5g was found to be the most potent anti-AChE derivate (5g, IC50 = 8.07 µM to DmAChE, IC50 = 32.24 µM to MdAChE). It was 2.31- and 1.35-fold more active than the positive control ethion (CP, IC50 = 18.62 µM to DmAChE, IC50 = 43.56 µM to MdAChE). The docking model study revealed that 5g possessed the fitted spatial structure and bound to the central pocket and peripheral site of DmAChE. Moreover, most compounds demonstrated high insecticidal activity to Lipaphis erysimi and Tetranychus cinnabarinus at the concentration of 300 mg/L.

Molecular-docking-guided design and synthesis of new IAA-tacrine hybrids as multifunctional AChE/BChE inhibitors

A series of new indole-3-acetic acid (IAA)-tacrine hybrids as dual acetylcholinesterase (AChE)/butyrylcholinesterase (BChE) inhibitors were designed and prepared based on the molecular docking mode of AChE with an IAA derivative (1a), a moderate AChE inhibitor identified by screening our compound library for anti-Alzheimer’s disease (AD) drug leads. The enzyme assay results revealed that some hybrids, e.g. 5d and 5e, displayed potent dual in vitro inhibitory activities against AChE/BChE with IC50 values in low nanomolar range. Molecular modeling studies in tandem with kinetic analysis suggest that these hybrids target both catalytic active site and peripheral anionic site of cholinesterase (ChE). Molecular dynamic simulations and Molecular Mechanics/Poisson-Boltzmann Surface Area (MM-PBSA) calculations indicate that 5e has more potent binding affinity than hit 1a, which may explain the stronger inhibitory effect of 5e on AChE. Furthermore, their predicted pharmacokinetic properties and in vitro influences on mouse brain neural network electrical activity were discussed. Taken together, compound 5e can be highlighted as a lead compound worthy of further optimization for designing new anti-AD drugs.

Total Synthesis of Pulmonarin B and Design of Brominated Phenylacetic Acid/Tacrine Hybrids: Marine Pharmacophore Inspired Discovery of New ChE and Aβ Aggregation Inhibitors.

A marine natural product, pulmonarin B (1), and a series of related tacrine hybrid analogues were synthesized and evaluated as cholinesterase (ChE) inhibitors. The in vitro ChE assay results revealed that 1 showed moderate dual acetylcholinesterase (AChE)/ butyrylcholinesterase (BChE) inhibitory activity, while the hybrid 12j proved to be the most potent dual inhibitor among the designed derivatives, being almost as active as tacrine. Molecular modeling studies together with kinetic analysis suggested that 12j interacted with both the catalytic active site and peripheral anionic site of AChE. Compounds 1 and 12j could also inhibit self-induced and AChE-induced Aβ aggregation. In addition, the cell-based assay against the human hepatoma cell line (HepG2) revealed that 1 and 12j did not show significant hepatotoxicity compared with tacrine and donepezil. Taken together, the present study confirmed that compound 1 was a potential anti-Alzheimer’s disease (AD) hit, and 12j could be highlighted as a multifunctional lead compound for anti-AD drug development.

Discovery of novel dual acetylcholinesterase inhibitors with antifibrillogenic activity related to Alzheimer's disease.

Alzheimer's disease is a progressive and neurodegenerative disorder of the CNS, affecting elderly people. The current pharmacological approach is based on the improvement of cholinergic neurotransmission by inhibiting acetylcholinesterase (AChE) with AChE inhibitors. The disease is also characterized by the accelerated accumulation of β-amyloid plaques around neurons. Furthermore, in vitro studies revealed that AChE can induce β-amyloid peptide (Aβ) aggregation. Computer-aided molecular design by virtual screening was here employed to discover novel potential AChE inhibitors, with antifibrillogenic properties, in other words, inhibiting Aβ aggregation. Compounds 1, 4 and 6 showed interesting AChE inhibition. In addition, they particularly inhibit Aβ aggregation in vitro, indicating to be promising novel anti-Alzheimer agents.

Design, synthesis and biological evaluation of dual acetylcholinesterase and phosphodiesterase 5A inhibitors in treatment for Alzheimer’s disease

With the recent research advances in molecular biology and technology, multiple credible hypotheses about the progress of Alzheimer’s disease (AD) have been proposed; multi-target drugs have emerged as an innovative therapeutic approach for AD. Current clinical therapy for AD patients is mainly palliative treatment targeting acetylcholinesterase (AChE). Inhibition of phosphodiesterase 5A (PDE5A) has recently been validated as a potentially novel therapeutic approach for Alzheimer’s disease (AD). In this work, series of new compounds were designed, synthesized and evaluated as dual cholinesterase and PDE5A inhibitor. Biological results revealed that some of these compounds display good biological activities against AChE with IC50 values about 44.67–169.80nM (donepezil IC50 50.12nM). Notably, compound 12 presented potent activities against PDE5A with IC50 values about 50μM (sildenafil IC50 12.59μM), and some of these compounds showed low cell toxicity to A549 cells in vitro.

DL0410, a novel dual cholinesterase inhibitor, protects mouse brains against Aβ-induced neuronal damage via the Akt/JNK signaling pathway.

1,1'-([1,1'-Biphenyl]-4,4'-diyl)bis(3-(piperidin-1-yl)propan-1-one)dihydrochloride (DL0410) is a novel synthetic dual acetylcholinesterase (AChE)/butyrocholinesterase (BuChE) inhibitor, which has shown a potential therapeutic effect on Alzheimer's disease (AD). In this study we examined whether DL0410 produced neuroprotective effects in an AD cellular model and an Aβ1-42-induced amnesia mouse model. The in vitro inhibitory activities against AChE and BuChE were estimated using Ellman's assay. Copper-induced toxicity in APPsw-SY5Y cells was used as AD cellular model, the cell viability was assessed using MTS assay, and cell apoptosis was evaluated based on mitochondrial membrane potential detection. Aβ1-42-induced amnesia mouse model was made in male mice by injecting aggregated Aβ1-42 (2 μg in 2 μL 0.1% DMSO) into the right cerebral ventricle. Before and after Aβ1-42 injection, the mice were orally administered DL0410 (1, 3, 9 mg·kg-1·d-1) or rivastigmine (2 mg·kg-1·d-1) for 3 and 11 d, respectively. Memory impairments were examined using Morris water maze (MWM) test and passive avoidance test. The expression levels of APP, CREB, BDNF, JNK and Akt in the mouse brains were measured with either immunohistochemistry or Western blotting. DL0410 exhibited in vitro inhibitory abilities against AChE and BuChE with IC50 values of 0.286±0.004 and 3.962±0.099 μmol/L, respectively, which were comparable to those of donepezil and rivastigmine. In APPsw-SY5Y cells, pretreatment with DL0410 (1, 3, and 10 μmol/L) decreased the phosphorylation of JNK and increased the phosphorylation of Akt, markedly decreased copper-stimulated Aβ1-42 production, reversed the loss of mitochondrial membrane potential, and dose-dependently increased the cell viability. In Aβ1-42-treated mice, DL0410 administration significantly ameliorated learning and memory deficits in MWM test and passive avoidance test. Furthermore, DL0410 administration markedly decreased Aβ1-40/42 deposits in mouse cerebral cortices, and significantly up-regulated neurotrophic CREB/BDNF. Meanwhile, Akt/JNK signaling pathway may play a key role in the neuroprotective effect of DL0410. DL0410 ameliorates cognitive deficit and exerts neuronal protection in AD models, implicating this compound as a candidate drug for the prevention and therapy of AD.

Novel N-allyl/propargyl tetrahydroquinolines: Synthesis via Three-component Cationic Imino Diels-Alder Reaction, Binding Prediction, and Evaluation as Cholinesterase Inhibitors.

New N‐allyl/propargyl 4‐substituted 1,2,3,4‐tetrahydroquinolines derivatives were efficiently synthesized using acid‐catalyzed three components cationic imino Diels–Alder reaction (70–95%). All compounds were tested in vitro as dual acetylcholinesterase and butyryl‐cholinesterase inhibitors and their potential binding modes, and affinity, were predicted by molecular docking and binding free energy calculations (∆G) respectively. The compound 4af (IC 50 = 72 μ m) presented the most effective inhibition against acetylcholinesterase despite its poor selectivity (SI = 2), while the best inhibitory activity on butyryl‐cholinesterase was exhibited by compound 4ae (IC 50 = 25.58 μ m) with considerable selectivity (SI = 0.15). Molecular docking studies indicated that the most active compounds fit in the reported acetylcholinesterase and butyryl‐cholinesterase active sites. Moreover, our computational data indicated a high correlation between the calculated ∆G and the experimental activity values in both targets.