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Background: Inhibition of cholinesterase enzyme has been recognized as an important target in the symptomatic treatment of Alzheimer’s disease. Objective: In the current work, a series of new N-(4-(imidazo[1,2-a]pyridin-2-yl)phenyl)cinnamamide derivatives were synthesized and their inhibitory activities against acetyl cholinesterase, butrylcholines terase, and Lipoxygenase were evaluated. Methods: The target compounds were synthesized as the literature reported with some modifications. The AChE, BChE, and LOX inhibitory activities of the synthesized compounds were evaluated using in vitro methods. The docking and kinetic studies were performed for the most potent compounds to evaluate the inhibition mechanism. Results: The structural elucidation of the synthesized imidazo-pyridine derivatives was performed by different spectroscopic techniques including IR, NMR, and Mass. Most of the synthesized compounds demonstrated good AChE, BChE, and LOX inhibitory activities. The most active AChE, BChE, and sLOX-1 inhibitors were found for compounds 4a, 4g, and 4l, respectively. The docking study also revealed that the three compounds, 4a, 4g, and 4l, have important binding interactions with the AChE, BChE, and sLOX-1 enzyme active sites, respectively. Conclusion: The results of current study shows imidazo[1,2-a]pyridine derivatives have potential for development of novel drug candidate for AD as AChE, BChE and sLOX-1 inhibitors.

The development of an effective and noninvasive early method for obtaining fetal cells is crucial to prenatal screening. Despite proving the presence of fetal cells in the reproductive tract, their use is limited due to their inability to properly isolate them from maternal cells. Magnetic-activated cell sorting (MACS) is a simple technique to separate cells. The present study aimed to develop a MACS-based platform for the isolation of the HLA-G expressing trophoblast cells. For this purpose, first, the triazine functionalized MNPs were synthesized and characterized. Then, MNPs were directly and indirectly conjugated by the MEM-G/9 antibodies targeting HLA-G+ cells. The antibody amount on the surface of the nanoparticles was determined with the Bradford assay. The cell capture efficiency was also investigated. Various characterization methods confirmed the successful nanoparticle synthesis and antibody conjugation. The optimal initial antibody amount for the immobilization was about 20 μg and the optimal time was 3 h. The antibody-nanoparticles by the indirect method had better targeting and capture efficiency than the direct method. The MNPs indirectly conjugated with antibodies are an efficient tool for cell isolation and present considerable potential to be applied in biomedical fields.

Background and purpose: Alzheimer’s disease is considered one of the lead causes of elderly death around the world. A significant decrease in acetylcholine level in the brain is common in most patients with Alzheimer’s disease, therefore acetylcholinesterase (AChE) inhibitors such as donepezil and rivastigmine are widely used for patients with limited therapeutic results and major side effects. Experimental approach: A series of isoindoline-1,3-dione -N-benzyl pyridinium hybrids were designed, synthesized and evaluated as anti-Alzheimer agents with cholinesterase inhibitory activities. The structure of the compounds were confirmed by various methods of analysis such as HNMR, CNMR, and FT-IR. Molecular modeling studies were also performed to identify the possible interactions between neprilysin and synthesized compounds. Findings/Results: The biological screening results indicated that all synthesized compounds displayed potent inhibitory activity with IC 50 values ranging from 2.1 to 7.4 µM. Among synthesized compounds, para-fluoro substituted compounds 7a and 7f exhibited the highest inhibitory potency against AChE (IC 50 = 2.1 µM). Molecular modeling studies indicated that the most potent compounds were able to interact with both catalytic and peripheral active sites of the enzyme. Also, some of the most potent compounds (7a, 7c, and 7f) demonstrated a neuroprotective effect against H 2 O 2 -induced cell death in PC12 neurons. Conclusion and implications: The synthesized compounds demonstrated moderate to good AChE inhibitory effect with results higher than rivastigmine.

Background: Acetylcholine deficiency in the hippocampus and cortex, aggregation of amyloid-beta, and beta-secretase overactivity have been introduced as the main reasons in the formation of Alzheimer’s disease. Objective: A new series of cinnamic derived acids linked to 1-benzyl-1,2,3-triazole moiety were designed, synthesized, and evaluated for their acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory activities. Methods: Colorimetric Ellman’s method was used for the determination of IC50% of AchE and BuChE inhibitory activity. The kinetic studies, neuroprotective activity, BACE1 inhibitory activity, evaluation of inhibitory potency on Aβ1-42 self-aggregation induced by AchE, and docking study were performed for studying the mechanism of action. Results: Some of the synthesized compounds, compound 7b-4 ((E)-3-(3,4-dimethoxyphenyl)-N-((1- (4-fluorobenzyl)-1H-1,2,3-triazole-4-yl) methyl) acrylamide) depicted the most potent acetylcholinesterase inhibitory activities ( IC50 = 5.27 μM ) and compound 7a-1 (N- ( (1- benzyl- 1H- 1, 2, 3- triazole - 4-yl) methyl) cinnamamide) demonstrated the most potent butyrylcholinesterase inhibitory activities (IC50 = 1.75 μM). Compound 7b-4 showed neuroprotective and β-secretase (BACE1) inhibitory activitiy. In vivo studies of compound 7b-4 in Scopolamine-induced dysfunction confirmed memory improvement. Conculusion: It should be noted that molecular modeling (compounds 7b-4 and 7a-1) and kinetic studies (compounds 7a-1 and 7b-4) showed that these synthesis compounds interacted simultaneously with both the catalytic site (CS) and peripheral anionic site (PAS) of AChE and BuChE.

A new series of 4-oxobenzo[d]1,2,3-triazin-pyridinium-phenylacetamide hybrids 8a–p was designed, synthesized, and screened as the potential cholinesterase inhibitors against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Obtained anti-cholinesterase activities demonstrated that all the title compounds exhibited excellent inhibition against BuChE and moderate inhibitory activity toward AChE in comparison to standard cholinesterase inhibitor donepezil. For example, compound 8e exhibited about 49-fold higher inhibitory activity than donepezil (IC50 = 3.2 ± 0.3 μM) against BuChE. This compound inhibited BuChE via a mixed-type inhibition mode. This finding demonstrated that compound 8e in addition to catalytic anionic site (CAS) can also interact with the peripheral anionic site (PAS) of BuChE. Molecular modeling and molecular dynamic studies were also performed on synthesized compounds.

A new series of compounds based on benzodiazepine-1,2,3-triazole were synthesized and evaluated as cholinesterase inhibitors by Ellman’s method. The compounds proved to be selective inhibitors of butyrylcholinesterase (BuChE) over acetylcholinesterase. The most potent compound was 3,3-dimethyl-11-(3-((1-(4-nitrobenzyl)-1H-1,2,3-triazol-4-yl)methoxy)phenyl)-2,3,4,5,10,11-hexahydro-1H-dibenzo[b,e][1,4]diazepin-1-one, identified as a submicromolar inhibitor of BuChE with IC50 value of 0.2 µM. In addition, the amyloid-β self-aggregation evaluation studies for selected compounds showed potent inhibitory effects compared to donepezil. The docking and cell viability studies supported the potential of compound 9b-6 as significant BuChE inhibitor.

A novel series of coumarin derivatives linked to the N-benzyl triazole group were synthesized and evaluated against 15-lipoxygenase (15-LOX), and acetyl- and butyrylcholinesterase (AChE and BuChE) to find the most potent derivative against Alzheimer’s disease (AD). Most of the compounds showed weak to moderate activity against ChEs. Among the most active BuChE and 15-LOX inhibitors, 8l and 8n exhibited an excellent neuroprotective effect, higher than the standard drug (quercetin) on the PC12 cell model injured by H2O2 and significantly reduced aggregation of amyloid Aβ1-42, with potencies of 1.44 and 1.79 times higher than donepezil, respectively. Compound 8l also showed more activity than butylated hydroxytoluene (BHT) as the reference antioxidant agent in reducing the levels of H2O2 activated by amyloid β in BV2 microglial cells. Kinetic and ligand–enzyme docking studies were also performed for better understanding of the mode of interaction between the best BuChE inhibitor and the enzyme. Considering the acceptable BuChE and 15-LOX inhibition activities as well as significant neuroprotection, and anti-amyloid aggregation activities, 8l and 8n could be considered as potential MTDLs for further modification and studies against AD.

The development of an effective and noninvasive early method for obtaining fetal cells is crucial to prenatal screening. Despite proving the presence of fetal cells in the reproductive tract, their use is limited due to their inability to properly isolate them from maternal cells. Magnetic-activated cell sorting (MACS) is a simple technique to separate cells. The present study aimed to develop a MACS-based platform for the isolation of the HLA-G expressing trophoblast cells. For this purpose, first, the triazine functionalized MNPs were synthesized and characterized. Then, MNPs were directly and indirectly conjugated by the MEM-G/9 antibodies targeting HLA-G

Novel 4-oxobenzo[d]1,2,3-triazin derivatives bearing pyridinium moiety 6a–q were synthesized and screened against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). Most of the synthesized compounds showed good inhibitory activity against AChE. Among the synthesized compounds, the compound 6j exhibited the highest AChE inhibitory activity. It should be noted that these compounds displayed low anti-BuChE activity with the exception of the compound 6i, as it exhibited BuChE inhibitory activity more than donepezil. The kinetic study of the compound 6j revealed that this compound inhibited AChE in a mixed-type inhibition mode. This finding was also confirmed by the docking study. The latter study demonstrated that the compound 6j interacted with both the catalytic site and peripheral anionic site of the AChE active site. The compound 6j was also observed to have significant neuroprotective activity against H2O2-induced PC12 oxidative stress, but low activity against β-secretase.

Alzheimer’s disease (AD) is a well-known neurodegenerative disorder affecting millions of old people worldwide and the corresponding epidemiological data highlights the significance of the disease. As AD is a multifactorial illness, various single-target directed drugs that have reached clinical trials have failed. Therefore, various factors associated with outset of AD have been considered in targeted drug discovery and development. In this work, a wide range of 1,2,3-triazole-chromenone carboxamides were designed, synthesized, and evaluated for their cholinesterase inhibitory activity. Among them, N-(1-benzylpiperidin-4-yl)-7-((1-(3,4-dimethylbenzyl)-1H-1,2,3-triazol-4-yl)methoxy)-2-oxo-2H-chromene-3-carboxamide (11b) showed the best acetylcholinesterase inhibitory activity (IC50 = 1.80 µM), however, it was inactive toward butyrylcholinesterase. It should be noted that compound 11b was evaluated for its BACE1 inhibitory activity and calculated IC50 = 21.13 µM confirmed desired inhibitory activity. Also, this compound revealed satisfactory neuroprotective effect against H2O2-induced cell death in PC12 neurons at 50 µM as well as metal chelating ability toward Fe2+, Cu2+, and Zn2+ ions.

A novel series of benzylpyridinium-based benzoheterocycles (benzimidazole, benzoxazole or benzothiazole) were designed as potent acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors. The title compounds 4a-q were conveniently synthesized via condensation reaction of 1,2-phenylenediamine, 2-aminophenol or 2-aminothiophenol with pyridin-4-carbalehyde, followed by N-benzylation using various benzyl halides. The results of in vitro biological assays revealed that most of them, especially 4c and 4g, had potent anticholinesterase activity comparable or more potent than reference drug, donepezil. The kinetic study demonstrated that the representative compound 4c inhibits AChE in competitive manner. According to the ligand-enzyme docking simulation, compound 4c occupied the active site at the vicinity of catalytic triad. The compounds 4c and 4g were found to be inhibitors of Aβ self-aggregation as well as AChE-induced Aβ aggregation. Meanwhile, these compounds could significantly protect PC12 cells against H2O2-induced injury and showed no toxicity against HepG2 cells. As multi-targeted structures, compounds 4c and 4g could be considered as promising candidate for further lead developments to treat Alzheimer's disease.

PURPOSE: Alzheimer’s disease (AD) is a multifaceted neurodegenerative disease. To target simultaneously multiple pathological processes involved in AD, natural-origin compounds with unique characteristics are promising scaffolds to develop novel multi-target compounds in the treatment of different neurodegenerative disease, especially AD. In this study, novel chromone-lipoic acid hybrids were prepared to find a new multifunctional lead structure for the treatment of AD. METHODS: Chromone-lipoic acid hybrids were prepared through click reaction and their neuroprotection and anticholinesterase activity were fully evaluated. The anti-amyloid aggregation, antioxidant and metal-chelation activities of the best compound were also investigated by standard methods to find a new multi-functional agent against AD. RESULTS: The primary biological screening demonstrated that all compounds had significant neuroprotection activity against H2O2-induced cell damage in PC12 cells. Compound 19 as the most potent butyrylcholinesterase (BuChE) inhibitor (IC50 = 7.55 μM) having significant neuroprotection activity as level as reference drug was selected for further biological evaluations. Docking and kinetic studies revealed non-competitive mixed-type inhibition of BuChE by compound 19. It could significantly reduce formation of the intracellular reactive oxygen species (ROS) and showed excellent reducing power (85.57 mM Fe+2), comparable with quercetin and lipoic acid. It could also moderately inhibit Aβ aggregation and selectively chelate with copper ions in 2:1 M ratio. CONCLUSION: Compound 19 could be considered as a hopeful multifunctional agent for the further development gainst AD owing to the acceptable neuroprotective and anti-BuChE activity, moderate anti-Aβ aggregation activity, outstanding antioxidant activity as well as selective copper chelation ability. GRAPHICAL ABSTRACT: [Figure: see text] SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1007/s40199-020-00378-1.

New series of triazole-containing 3-phenylcoumarin-lipoic acid conjugates were designed as multi-functional agents for treatment of Alzheimer's disease. The target compounds 4a-o were synthesized via the azide-alkyne cycloaddition reaction and their biological activities were primarily evaluated in terms of neuroprotection against H2O2-induced cell death in PC12 cells and AChE/BuChE inhibition. The promising compounds 4j and 4i containing four carbons spacer were selected for further biological evaluations. Based on the obtained results, the benzocoumarin derivative 4j with IC50 value of 7.3 µM was the most potent AChE inhibitor and displayed good inhibition toward intracellular reactive oxygen species (ROS). This compound with antioxidant and metal chelating ability showed also protective effect on cell injury induced by Aβ1-42 in SH-SY5Y cells. Although the 8-methoxycoumarin analog 4i was slightly less active than 4j against AChE, but displayed higher protection ability against H2O2-induced cell death in PC12 and could significantly block Aβ-aggregation. The results suggested that the prototype compounds 4i and 4j might be promising multi-functional agents for the further development of the disease-modifying treatments of Alzheimer's disease.

Alzheimer’s disease (AD) is the most common form of dementia. Inhibition of BChE might be a useful therapeutic target for AD. A new series of Carbazole-Benzyl Pyridine derivatives were designed synthesized and evaluated as butyrylcholinesterase (BChE) inhibitors. In vitro assay revealed that all of the derivatives had selective and potent anti- BChE activities. 3-((9H-Carbazol-9-yl)methyl)-1-(4-chlorobenzyl)pyridin-1-ium chloride (compound 8f) had the most potent anti-BChE activity (IC50 value = 0.073 μM), the highest BChE selectivity and mixed-type inhibition. Docking study revealed that 8f interacted with the peripheral site, the choline binding site, catalytic site and the acyl pocket of BChE. Physicochemical properties were accurate to Lipinski's rule. In addition, compound 8f demonstrated neuroprotective activity at 10 µM. This compound could also inhibit AChE-induced and self-induced Aβ peptide aggregation at concentration of 100 µM and 10 µM respectively. The in-vivo study showed that compound 8f in 10 mg/kg increased the time spent in target quadrant in the probe day and decreased mean training period scape latency in rats. All results suggest that new sets of potent selective inhibitors of BChE have a therapeutic potential for the treatment of AD.

A novel hybrid series of umbellipherone and benzyl amine scaffolds, linked via triazole ring, was synthesized and evaluated as both acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitors. Most of the synthesized compounds showed moderate to high activities by using Ellman’s modified assay. Among the target compounds, 6e bearing 3-methoxy substituent on benzyl moiety was the most active one (AChE and BuChE IC50 = 3.4 and 1.1 μM, respectively). Finally, binding modes of the target compound was studied using molecular docking stimulations. The neuroprotectivity evaluation exhibited that this compound efficiently protected PC12 neurons against H2O2-induced cell death.

A novel series of coumarin-lipoic acid conjugates were synthesized via cycloaddition click reaction to find out new multi-target-directed ligands (MTDLs) for treatment of Alzheimer's disease (AD). All of synthesized compounds were screened for neuroprotective and anti-cholinesterase activities. Based on primary screening, two compounds (5 and 11) were subjected to further biological evaluations. In particular, compound 11 which was the most potent AChE inhibitor showed good inhibitory effect on Aβ-aggregation and intracellular ROS (reactive oxygen species) formation, as well as the ability of selective bio-metal chelation and neuroprotection against H2O2- and Aβ1-42-induced cytotoxicity. In the light of these results, the applied hybridization approach introduced new promising lead compound with desired multifunctional properties, being useful in the treatment of Alzheimer's disease.

An efficient aldol condensation/click reaction sequence is employed for the synthesis of chalcone-triazole-based derivatives in moderate to good yields. The ability of target compounds to inhibit 15-lipoxygenase enzyme was investigated and moderate to low inhibitory activities were observed for the synthesized compounds.

A new series of N-(1-benzylpiperidin-4-yl) quinoline-4-carboxamide derivatives was designed and synthesized as potential acetylcholinesterase inhibitors. The compounds were characterized by nuclear magnetic resonance, infrared and mass spectrometry. In the amidation reaction in addition of target compounds 5a-5 h, a bis-N-acylurea were also obtained especially when we added more carbonyldiimidazole (CDI) for the completion of the reaction. Although docking study of these compounds predicted that they will inhibit acetylcholinesterase (AChE) protein strongly and more than the reference drugs, the in vitro evaluation of the quinolines 5a-5 h revealed that most of them had moderate activity toward AChE. The results showed that there is a correlation between anticholinesterase inhibitory potency and docking energy of compounds. Among these compounds, 5f with the lowest docking energy, exhibited the most anticholinesterase inhibitory potency. Molecular dynamics simulation and molecular docking studies of compound 5f into the binding site of acetylcholinesterase exhibited the probable interactions of 5f with the binding site of acetylcholinesterase.

Novel pyrano[3,2-c]chromene derivatives bearing morpholine/phenylpiperazine moiety were synthesized and evaluated against acetylcholinestrase (AChE) and butylcholinestrase (BuChE). Among the synthesized compounds, N-(3-cyano-4-(4-methoxyphenyl)-5-oxo-4,5-dihydropyrano[3,2-c]chromen-2-yl)-2-(4-phenylpiperazin-1-yl)acetamide (6c) exhibited the highest acetylcholinestrase inhibitory (AChEI) activity (IC50=1.12µM) and most of them showed moderate butylcholinestrase inhibitory activity (BChEI). Kinetic study of compound 6c confirmed mixed type of inhibition towards AChE which was in covenant with the results obtained from docking study. Also, it was evaluated against β-secretase which demonstrated low activity (inhibition percentage: 18%). It should be noted that compounds 6c, 7b, 6g, and 7d showed significant neuroprotective effects against H2O2-induced PC12 oxidative stress.

A series of poly-functionalized tacrine-derived compounds namely 5-amino-2-phenyl-4H-pyrano[2,3-b]quinoline-3-carboxylates were designed and synthesized as cholinesterases inhibitors. The in vitro inhibition assay against AChE and BuChE demonstrated that most of compounds had potent AChE inhibitory with reserving potential of BuChE inhibition. Among them, compound 6i bearing a 4-(3-bromophenyl) moiety showed the most potent activity against AChE/BuChE (IC50s values of 0.069 and 1.35 μM, respectively). The anti-AChE activity of 6i was five times more than that of tacrine. The SAR study revealed that chloro/bromo substituent at ortho or meta position of the 4-phenyl ring can improve the anticholinesterase activity.

Novel coumarin–tryptamine systems attached through a linker were synthesised and evaluated in vitro against acetylcholinesterase by the classical Ellman's test.

A series of 20 novel benzimidazole and benzothiazole derivatives linked to a 1,2,3-triazole ring system was synthesised, characterised and evaluated for in vitro acetylcholinesterase (AChE) inhibitory activity. Several copper catalysts and solvents were screened to establish the optimal conditions for the preparation of the target compounds. Three different linkers were used to optimise the enzyme inhibitory effect. Out of the 20 compounds, 13 showed some AChE inhibition. The most potent compound, which showed 84% inhibition at 100 μM, contained a 1-(2-fluorobenzyl)-1,2,3-triazole linked to a benzimidazole group. A docking simulation study showed that the most active compound bound preferentially to the catalytic anionic subsite of the AChE enzyme.

A series of novel benzo[d]oxazole derivatives (6a–n) have been synthesized and biologically evaluated as potential inhibitors of acetylcholinesterases (AChE) and butyrylcholinesterase (BChE). The chemical structures of all final compounds were confirmed by spectroscopic methods. In vitro studies showed that most of the synthesized compounds are potent acetylcholinesterase and butyrylcholinesterase inhibitors. Among them, compounds 6a and 6j strongly inhibited AChE and BChE activities with IC50 values of 1.03–1.35 and 6.6–8.1 μm, respectively. Docking studies also provided the binding modes of action and identified hydrophobic pi forces as the main interaction.

A novel series of phthalimide-dithiocarbamate hybrids was synthesized and evaluated for in vitro inhibitory potentials against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). The anti-cholinesterase results indicated that among the synthesized compounds, the compounds 7g and 7h showed the most potent anti-AChE and anti-BuChE activities, respectively. Molecular docking and dynamic studies of the compounds 7g and 7h, respectively, in the active site of AChE and BuChE revealed that these compounds as well interacted with studied cholinesterases. These compounds also possessed drug-like properties and were able to cross the BBB.

Background: The first line treatment for cutaneous leishmaniasis is pentavalent antimony such as sodium stibogluconate (pentostam) and meglumine antimonite (glucantime). One of the most important ways to uptake the drug is by a transmembrane protein, called aquaglyceroporin encoded by Aquaglyceroprotein1 (LmAQP1). In this study, molecular characterization of LmAQP1 was reported. Methods: Leishmania major (MRHO/IR/75/ER) promastigotes were cultured, and then DNA extraction and RNA extraction were done and followed by cDNA synthesis. Amplicons resulted from PCR and RT-PCR using specific primers were purified and sequenced. Molecular characterization was done by bioinformatically software such as BLST, ClustalW2, and RMSD. Results: Amplicons resulted from PCR and RT-PCR showed equal size in length. BLASTn analysis showed a point nucleotide change in LmAQP1 gene that encoded 282-amino-acid long protein with a mutation at position 154 including replacement of alanine by threonine. The observed mutation in the interested gene was assessed using the above-mentioned software. The mentioned gene was submitted at GenBank, NCBI with accession number of KU514052. Conclusion: The functional prediction of the protein encoded from LmAQP1 showed that the mentioned mutation could not affect the three-dimension structure, but it may modify the drug uptake potential of this important channel. Based on from LmAQP1 role, it seems to be an appropriate candidate for drug development. According to search through internet, this is the first report of LmAQP1 from L. major (MRHO/IR/75/ER).

BACKGROUND: Acetylcholine deficiencies in hippocampus and cortex, aggregation of β-amyloid, and β-secretase over activity have been introduced as main reasons in pathogenesis of Alzheimer’s disease. METHODS: Colorimetric Ellman’s method was used for determination of IC(50) value in AChE and BChE inhibitory activity. The kinetic studies, neuroprotective and β-secretase inhibitory activities, evaluation of inhibitory potency on β-amyloid (Aβ) aggregations induced by AChE, and docking study were performed for prediction of the mechanism of action. RESULT AND DISCUSSION: A new series of cinnamic acids-tryptamine hybrid was designed, synthesized, and evaluated as dual cholinesterase inhibitors. These compounds demonstrated in-vitro inhibitory activities against acetyl cholinesterase (AChE) and butyryl cholinesterase (BChE). Among of these synthesized compounds, (E)-N-(2-(1H-indol-3-yl)ethyl)-3-(3,4-dimethoxyphenyl)acrylamide (5q) demonstrated the most potent AChE inhibitory activity (IC(50) = 11.51 μM) and (E)-N-(2-(1H-indol-3-yl)ethyl)-3-(2-chlorophenyl)acrylamide (5b) were the best anti-BChE (IC(50) = 1.95 μM) compounds. In addition, the molecular modeling and kinetic studies depicted 5q and 5b were mixed type inhibitor and bound with both the peripheral anionic site (PAS) and catalytic sites (CAS) of AChE and BChE. Moreover, compound 5q showed mild neuroprotective in PC12 cell line and weak β-secretase inhibitory activities. This compound also inhibited aggregation of β-amyloid (Aβ) in self-induced peptide aggregation test at concentration of 10 μM. CONCLUSION: It is worth noting that both the kinetic study and the molecular modeling of 5q and 5b depicted that these compounds simultaneously interacted with both the catalytic active site and the peripheral anionic site of AChE and BChE. These findings match with those resulted data from the enzyme inhibition assay. [Figure: see text] ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1007/s40199-020-00346-9) contains supplementary material, which is available to authorized users.

A new series of coumarin-3-carboxamide-N-morpholine hybrids 5a-5l was designed and synthesized as cholinesterases inhibitors. The synthetic approach for title compounds was started from the reaction between 2-hydroxybenzaldehyde derivatives and Meldrum's acid to afford corresponding coumarin-3-carboxylic acids. Then, amidation of the latter compounds with 2-morpholinoethylamine or N-(3-aminopropyl)morpholine led to the formation of the compounds 5a-5l. The in vitro inhibition screen against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) revealed that most of the synthesized compounds had potent AChE inhibitory while their BuChE inhibitions are moderate to weak. Among them, propylmorpholine derivative 5g (N-[3-(morpholin-4-yl)propyl]-2-oxo-2H-chromene-3-carboxamide) bearing an unsubstituted coumarin moiety and ethylmorpholine derivative 5d (6-bromo-N-[2-(morpholin-4-yl)ethyl]-2-oxo-2H-chromene-3-carboxamide) bearing a 6-bromocoumarin moiety showed the most activity against AChE and BuChE, respectively. The inhibitory activity of compound 5g against AChE was 1.78 times more than that of rivastigmine and anti-BuChE activity of compound 5d is approximately same as rivastigmine. Kinetic and docking studies confirmed the dual binding site ability of compound 5g to inhibit AChE.

Inhibition of butyrylcholinesterase (BChE) might be a useful therapeutic target for Alzheimer’s disease (AD). A new series of 1,2,3,4-tetrahydro-9H-carbazole derivatives were designed synthesized and evaluated as BChE inhibitors. While all of the derivatives have shown for AChE IC50 values below the detectable limit (> 100 µM), they were selective potent BChE inhibitors. 1-(2-(6-fluoro-1,2,3,4-tetrahydro-9H-carbazole-9-yl)ethyl)piperidin-1-ium chloride (15 g) had the most potent anti-BChE activity (IC50 value = 0.11 μM), the highest BChE selectivity and mixed-type inhibition. Pharmacokinetic properties were accordant to Lipinski rule and compound 15g demonstrated neuroprotective and inhibition of β-secretase (BACE1) activities. Furthermore, in vivo study of compound 15g in Morris water maze task has confirmed memory improvement in scopolamine-induced impairment. All results suggest that new sets of potent selective inhibitors of BChE have a therapeutic potential for the treatment of AD. A new series of 1,2,3,4-tetrahydro-9H-carbazole derivatives were designed synthesized and evaluated as BChE inhibitors. While all of the derivatives have shown for AChE IC50 values below the detectable limit, they were selective potent BChE inhibitors. Compound 15g had the most potent anti-BChE activity. All results suggest that new sets of potent selective inhibitors of BChE have a therapeutic potential for the treatment of AD.

مقدمه: آنزیم لیپواکسیژناز در بیوسنتز لوکوتری‌ان ها نقش دارد که اثرات فارماکولوژیک مختلفی در بدن دارند. اثرات درمانی مهار این آنزیم در برخی از بیماری ها مانند آسم، سرطان و آلزایمر به اثبات رسیده است. لذا مهارکننده‌های این آنزیم می توانند به عنوان درمان دارویی در برخی از شرایط پاتولوژیک و بیماری ها مورد استفاده قرارگیرند. در این مطالعه مشتقات هتروآریل 2-فنوکسی پیریدین-3-ایل سنتز و اثرات مهاری آنها بر آنزیم لیپواکسیژناز بررسی شده است. روش بررسی: در این مطالعه بنیادی – کاربردی، مشتقات مورد نظر به عنوان مهارکننده لیپواکسیژناژ به روش های مرسوم طی چند مرحله سنتز شدند. سپس ساختار ترکیبات با استفاده از طیف سنجی مادون‌قرمز، جرمی و رزونانس مغناطیسی هسته مورد تائید قرار گرفت. در نهایت اثرات مهاری لیپواکسیژناز این ترکیبات بررسی و مطالعات داکینگ مولکولی روی قوی ترین ترکیب صورت گرفت. نتایج: ترکیبات با بازده بالا سنتز شده و اثرات مهار لیپواکسیژناز خوبی (IC50 =100-179 mM) در مقایسه با استاندارد کوئرستین (IC50 = 58.5 mM) از خود نشان دادند. در این بین ترکیب ترکیب 7a ( 5-(2-فنوكسي پيريدين-3-ايل)-1و3و4- اكساديازول-2(H3)-تيون ) قوی‌ترین اثرات را از خود نشان داد و مطالعات داکینگ مولکولی روی این ترکیب نشان داد که به خوبی می تواند در اکتیو سایت آنزیم قرار گیرد. نتیجه‌گیری: ترکیبات سنتز شده اثرات مهاری خوبی بر آنزیم لیپواکسیژناز از خود نشان دادند و مطالعات داکینگ مولکولی نشان داد این ترکیبات به خوبی در اکتیو سایت آنزیم قرار می گیرند. لذا می‌توانند به عنوان ترکیب اولیه جهت مطالعات بیشتر در جهت کشف داروهای جدید مهار کننده لیپواکسیژناز مورد استفاده قرار گیرند.

A new serise of 7-hydroxy-chromone derivatives bearing pyridine moiety were synthesized, and evaluated as multifunctional agents against Alzheimer’s disease (AD). Most of the compounds were good AChE inhibitors (IC50 = 9.8–0.71 µM) and showed remarkable BuChE inhibition activity (IC50 = 1.9–0.006 µM) compared with donepezil as the standard drug (IC50 = 0.023 and 3.4 µM). Compounds 14 and 10 showed the best inhibitory activity toward AChE (IC50 = 0.71 µM) and BuChE (IC50 = 0.006 µM), respectively. The ligand–protein docking simulations and kinetic studies revealed that compound 14 and 10 could bind effectively to the peripheral anionic binding site (PAS) of the AChE and BuChE through mixed-type inhibition. In addition, the most potent compounds showed acceptable neuroprotective activity on H2O2- and Aβ-induced .neurotoxicity in PC12 cells, more than standard drugs. The compounds could block effectively self- and AChE-induced Aβ aggregation. All the results suggest that compounds 14 and 10 could be considered as promising multi-target-directed ligands against AD.

As anandamide (N-arachidonoylethanolamine, AEA) shows neuroprotective effects, the inhibition of its degradative enzyme, fatty acid amide hydrolase (FAAH) has been considered as a hopeful avenue for the treatment of neurodegenerative diseases, like Alzheimer’s disease (AD). Memory loss, cognitive impairment and diminution of the cholinergic tone, due to the dying cholinergic neurons in the basal forebrain, are common hallmarks in patients with AD. By taking advantage of cholinesterase inhibitors (ChEIs), the degradation of acetylcholine (ACh) is decreased leading to enhanced cholinergic neurotransmission in the aforementioned region and ultimately improves the clinical condition of AD patients. In this work, new carbamates were designed as inhibitors of FAAH and cholinestrases (ChEs) (acetylcholinestrase (AChE), butyrylcholinestrase (BuChE)) inspired by the structure of the native substrates, structure of active sites and the SARs of the well-known inhibitors of these enzymes. All the designed compounds were synthesized using different reactions. All the target compounds were tested for their inhibitory activity against FAAH and ChEs by employing the Cayman assay kit and Elman method respectively. Generally, compounds possessing aminomethyl phenyl linker was more potent compared to their corresponding compounds possessing piperazinyl ethyl linker. The inhibitory potential of the compounds 3a-q extended from 0.83 ± 0.03 μM (3i) to ˃100 μM (3a) for FAAH, 0.39 ± 0.02 μM (3i) to 24% inhibition in 113 ± 4.8 μM (3b) for AChE, and 1.8 ± 3.2 μM (3i) to 23.2 ± 0.2 μM (3b) for BuChE. Compound 3i a heptyl carbamate analog possessing 2-oxo-1,2-dihydroquinolin ring and aminomethyl phenyl linker showed the most inhibitory activity against three enzymes. Also, compound 3i was investigated for memory improvement using the Morris water maze test in which the compound showed better memory improvement at 10 mg/kg compared to reference drug rivastigmine at 2.5 mg/kg. Molecular docking and molecular dynamic studies of compound 3i into the enzymes displayed the possible interactions of key residues of the active sites with compound 3i. Finally, kinetic study indicated that 3i inhibits AChE through the mixed- mode mechanism and non-competitive inhibition mechanism was revealed for BuChE.

The combination of heterocycles offers a new opportunity to create novel multicyclic compounds having improved biological activity. Coumarins are ubiquitous natural heterocycle widely adopted in the design of various biologically active compounds. Fusing different heterocycles with coumarin ring is one of the interesting approaches to generating novel hybrid molecules having highlighted biological activities. In the efforts to develop heterocyclic-fused coumarins, a wide range of 3,4-heterocycle-fused coumarins have been introduced bearing outstanding biological activity. The effect of heterocycles annulation at 3,4-positions of coumarin ring on the biological activity of the target structures were discussed. This review focuses on the important progress of 3,4-heterocycle-fused coumarins providing better insight for medicinal chemists on the design and preparation of biologically active heterocycle-fused coumarins with a significant therapeutic effect in the future.

Alzheimer’s disease (AD) as the most common form of dementia in aged people, is an intricate neurodegenerative disease. Therefore, a novel strategy so-called multi-target-directed ligand has received much attention for the effective treatment of AD. In this study a series of novel carbazole-benzylpiperidine hybrids 9a-m was designed, synthesized and evaluated as acetylcholinesterase and butyrylcholinesterase inhibitors. Moreover, some of these compounds were evaluated for anti β-secretase (BACE1) activity and metal chelation properties. Among the synthesized compounds, compounds 9b (IC50 = 16.5 μM for AChE and IC50 = 0.59 μM for BuChE) and 9c (IC50 = 26.5 μM for AChE and IC50 = 0.18 μM for BuChE) showed the highest inhibitory activity against acetylcholinesterase and butyrylcholinesterase. Furthermore, these compounds (9b and 9c) displayed interaction with Zn2+ ion and compound 9c showed moderate inhibitory activity against BACE1 (24.5% at 50 μM). Kinetic and docking studies exhibited that these compounds likely act as a non-competitive inhibitor able to interact with the catalytic active site (CAS) and peripheral anionic site (PAS) of acetylcholinesterase simultaneously.

An approach for the construction of benzotriazinone-triazole system is described. The synthesis is based on diazonium chemistry and subsequent intramolecular heteroatom-heteroatom bond formation. The introduction of triazole moiety occurred via click reaction catalyzed by nano-sized copper, supported on modified silica mesopore KIT-5 leading to the desired products in excellent yield. Also, in vitro acetylcholinesterase (AChE) inhibitory activities of the target compounds were screened by Ellman’s method.

We report a solvent-free synthesis of novel 1,3,4,5-tetrasubstituted pyrazoles and investigate their inhibitory activity against soybean 15-lipoxygenase. It was revealed that all synthesized compounds exhibited good activity, and among them, 3-(furan-2-yl)-1,4,5-triphenyl-1H-pyrazole (5j) showed 10 times stronger inhibitory activity in comparison to the reference drug quercetin.

A series of chromene-fused coumarins known as 10,11-dihydrochromeno[4,3-b]chromene-6,8(7H,9H)-diones 4a–o were synthesized through one-pot reaction of appropriate benzaldehydes, dimedone, and 4-hydroxycoumarin in the presence of nano-silica sulfuric acid under solvent-free condition in good yields. The in vitro anticholinesterase assay revealed that the 3-hydroxyphenyl analog 4e showed the highest inhibitory activity against both acetylcholinesterase and butyrylcholinesterase, possessing IC50 values of 3.28 and 2.19 µM, respectively. The structure-activity relationships study demonstrated that the selectivity for acetylcholinesterase over butyrylcholinesterase could be modulated by introducing second hydroxyl or methoxy substituent on the para-position of the 3-hydroxyphenyl pendent group. The docking study of compound 4e with acetylcholinesterase confirmed π–π stacking interaction between the coumarin moiety and Trp279 as well as the formation of hydrogen bonding between hydroxyl group and Asn85.

This work reports the successful synthesis of quinazolinones carrying triazole derivatives with potent lipoxygenase inhibitory activities. This protocol involves sequential reactions affording novel products in high yields without the need for a tedious work-up procedure.