Design, synthesis and evaluation of quinoline-O-carbamate derivatives as multifunctional agents for the treatment of Alzheimer's disease

Novel anti-neuroinflammatory pyranone-carbamate derivatives as selective butyrylcholinesterase inhibitors for treating Alzheimer's disease

Butyrylcholinesterase (BuChE) and neuroinflammation have recently emerged as promising therapeutic directions for Alzheimer's disease (AD). Herein, we synthesised 19 novel pyranone-carbamate derivatives and evaluated their activities against cholinesterases and neuroinflammation. The optimal compound 7p exhibited balanced BuChE inhibitory activity (eqBuChE IC50 = 4.68 nM; huBuChE IC50 = 9.12 nM) and anti-neuroinflammatory activity (NO inhibition = 28.82% at 10 μM, comparable to hydrocortisone). Enzyme kinetic and docking studies confirmed compound 7p was a mix-type BuChE inhibitor. Additionally, compound 7p displayed favourable drug-likeness properties in silico prediction, and exhibited high BBB permeability in the PAMPA-BBB assay. Compound 7p had good safety in vivo as verified by an acute toxicity assay (LD50 > 1000 mg/kg). Most importantly, compound 7p effectively mitigated cognitive and memory impairments in the scopolamine-induced mouse model, showing comparable effects to Rivastigmine. Therefore, we envisioned that compound 7p could serve as a promising lead compound for treating AD.

Design of Multi-Target drugs of HDACs and other Anti-Alzheimer related Targets: Current strategies and future prospects in Alzheimer's diseases therapy

Alzheimer disease (AD) is the most prevalent form of dementia that develops spontaneously in the elderly. It's worth mentioning that as people age, the epigenetic profile of the central nervous system cells changes, which may speed up the development of various neurodegenerative disorders including AD. Histone deacetylases (HDACs) are a class of epigenetic enzymes that can control gene expression without altering the gene sequence. Moreover, a promising strategy for multi-target hybrid design was proposed to potentially improve drug efficacy and reduce side effects. These hybrids are monocular drugs that contain various pharmacophore components and have the ability to bind to different targets at the same time. The HDACs ability to synergistically boost the performance of other anti-AD drugs, as well as the ease with which HDACs inhibitor cap group, can be modified. This has prompted numerous medicinal chemists to design a novel generation of HDACs multi-target inhibitors. Different HDACs inhibitors and other ones such as acetylcholinesterase, butyryl-cholinesterase, phosphodiesterase 9, phosphodiesterase 5 or glycogen synthase kinase 3β inhibitors were merged into hybrids for treatment of AD. This review goes over the scientific rationale for targeting HDACs along with several other crucial targets in AD therapy. This review presents the latest hybrids of HDACs and other AD target pharmacophores.

Synthesis of Ethyl Pyrimidine-Quinolincarboxylates Selected from Virtual Screening as Enhanced Lactate Dehydrogenase (LDH) Inhibitors

The inhibition of the hLDHA (human lactate dehydrogenase A) enzyme has been demonstrated to be of great importance in the treatment of cancer and other diseases, such as primary hyperoxalurias. In that regard, we have designed, using virtual docking screening, a novel family of ethyl pyrimidine-quinolinecarboxylate derivatives (13-18)(a-d) as enhanced hLDHA inhibitors. These inhibitors were synthesised through a convergent pathway by coupling the key ethyl 2-aminophenylquinoline-4-carboxylate scaffolds (7-12), which were prepared by Pfitzinger synthesis followed by a further esterification, to the different 4-aryl-2-chloropyrimidines (VIII(a-d)) under microwave irradiation at 150-170 °C in a green solvent. The values obtained from the hLDHA inhibition were in line with the preliminary of the preliminary docking results, the most potent ones being those with U-shaped disposition. Thirteen of them showed IC50 values lower than 5 μM, and for four of them (16a, 18b, 18c and 18d), IC50 ≈ 1 μM. Additionally, all compounds with IC50 < 10 μM were also tested against the hLDHB isoenzyme, resulting in three of them (15c, 15d and 16d) being selective to the A isoform, with their hLDHB IC50 > 100 μM, and the other thirteen behaving as double inhibitors.

A high-throughput system for drug screening based on the movement analysis of zebrafish

Zebrafish is a highly advantageous model animal for drug screening and toxicity evaluation thanks to its amenability to optical imaging (i.e., transparency), possession of organ structures similar to humans, and the ease with which disease models can be established. However, current zebrafish drug screening technologies and devices suffer from limitations such as low level of automation and throughput, and low accuracy caused by the heterogeneity among individual zebrafish specimens. To address these issues, we herein develop a high-throughput zebrafish drug screening system. This system is capable of maintaining optimal culturing conditions and simultaneously monitoring and analyzing the movement of 288 zebrafish larvae under various external conditions, such as drug combinations. Moreover, to eliminate the effect of heterogeneity, locomotion of participating zebrafish is assessed and grouped before experiments. It is demonstrated that in contrast to the experimental results without pre-selection, which shows ∼20 % damaged motor function (i.e., degree of attenuation), the drug-induced variations among zebrafish with equivalent mobility reaches ∼80 %. Overall, our high-throughput zebrafish drug screening system overcomes current limitations by improving automation, throughput, and accuracy, resulting in enhanced detection of drug-induced variations in zebrafish motor function.

The Versatile and Strategic O-Carbamate Directed Metalation Group in the Synthesis of Aromatic Molecules: An Update

The aryl O-carbamate (ArOAm) group is among the strongest of the directed metalation groups (DMGs) in directed ortho metalation (DoM) chemistry, especially in the form Ar-OCONEt2. Since the last comprehensive review of metalation chemistry involving ArOAms (published more than 30 years ago), the field has expanded significantly. For example, it now encompasses new substrates, solvent systems, and metalating agents, while conditions have been developed enabling metalation of ArOAm to be conducted in a green and sustainable manner. The ArOAm group has also proven to be effective in the anionic ortho-Fries (AoF) rearrangement, Directed remote metalation (DreM), iterative DoM sequences, and DoM-halogen dance (HalD) synthetic strategies and has been transformed into a diverse range of functionalities and coupled with various groups through a range of cross-coupling (CC) strategies. Of ultimate value, the ArOAm group has demonstrated utility in the synthesis of a diverse range of bioactive and polycyclic aromatic compounds for various applications.

Tailored Melatonin- and Donepezil-Based Hybrids Targeting Pathognomonic Changes in Alzheimer's Disease: An In Vitro and In Vivo Investigation

A plethora of pathophysiological events have been shown to play a synergistic role in neurodegeneration, revealing multiple potential targets for the pharmacological modulation of Alzheimer's disease (AD). In continuation to our previous work on new indole- and/or donepezil-based hybrids as neuroprotective agents, the present study reports on the beneficial effects of lead compounds of the series on key pathognomonic features of AD in both cellular and in vivo models. An enzyme-linked immunosorbent assay (ELISA) was used to evaluate the anti-fibrillogenic properties of 15 selected derivatives and identify quantitative changes in the formation of neurotoxic β-amyloid (Aβ42) species in human neuronal cells in response to treatment. Among the most promising compounds were 3a and 3c, which have recently shown excellent antioxidant and anticholinesterase activities, and, therefore, have been subjected to further in vivo investigation in mice. An acute toxicity study was performed after intraperitoneal (i.p.) administration of both compounds, and 1/10 of the LD50 (35 mg/kg) was selected for subacute treatment (14 days) with scopolamine in mice. Donepezil (DNPZ) and/or galantamine (GAL) were used as reference drugs, aiming to establish any pharmacological superiority of the multifaceted approach in battling hallmark features of neurodegeneration. Our promising results give first insights into emerging disease-modifying strategies to combine multiple synergistic activities in a single molecule.

Design, synthesis and biological evaluation of bakuchiol derivatives as multi-target agents for the treatment of Alzheimer's disease

The concept of multi-target-directed ligands offers fresh perspectives for the creation of brand-new Alzheimer's disease medications. To explore their potential as multi-targeted anti-Alzheimer's drugs, eighteen new bakuchiol derivatives were designed, synthesized, and evaluated. The structures of the new compounds were elucidated by IR, NMR, and HRMS. Eighteen compounds were assayed for acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) in vitro using Ellman's method. It was shown that most of the compounds inhibited AChE and BuChE to varying degrees, but the inhibitory effect on AChE was relatively strong, with fourteen compounds showing inhibition of >50% at the concentration of 200 μM. Among them, compound 3g (IC50 = 32.07 ± 2.00 μM) and compound 3n (IC50 = 34.78 ± 0.34 μM) showed potent AChE inhibitory activities. Molecular docking studies and molecular dynamics simulation showed that compound 3g interacts with key amino acids at the catalytically active site (CAS) and peripheral anionic site (PAS) of acetylcholinesterase and binds stably to acetylcholinesterase. On the other hand, compounds 3n and 3q significantly reduced the pro-inflammatory cytokines TNF-α and IL-6 released from LPS-induced RAW 264.7 macrophages. Compound 3n possessed both anti-acetylcholinesterase activity and anti-inflammatory properties. Therefore, an in-depth study of compound 3n is expected to be a multi-targeted anti-AD drug.

Quinoline-sulfonamides as a multi-targeting neurotherapeutic for cognitive decline: in vitro, in silico studies and ADME evaluation of monoamine oxidases and cholinesterases inhibitors

Alzheimer's disease (AD) is a multifactorial irreversible neurological disorder with multiple enzymes involved. In the treatment of AD, multifunctional agents targeting cholinesterase (ChE) and monoamine oxidase (MAO) inhibitors have shown promising results. Herein, a series of novel quinoline-sulfonamides (a1-18) were designed and synthesized as a dual inhibitor of MAOs and ChEs. The in vitro results showed that compounds a5, a12, a11, and a6 exhibited the most potent compounds against specific enzymes. They had IC50 value 0.59 ± 0.04 for MAO-A, 0.47 ± 0.03 for MAO-B, 0.58 ± 0.05 for BChE and 1.10 ± 0.77 for AChE μM respectively. Furthermore, kinetic studies revealed that these compounds are competitive. Molecular docking studies enhanced the understanding of the in silico component, unveiling critical interactions, specifically the hydrogen bonding interaction, π-π, π-alkyl, π-amid and π-sulfur interactions between the ligand and enzymes. These findings suggest that compounds a5, a6, a11, a12, a15, and a18 may be potent multifunctional candidates for AD treatment.

A comprehensive review of multi-target directed ligands in the treatment of Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia affecting specifically older population. AD is an irreversible neurodegenerative CNS disorder associated with complex pathophysiology. Presently, the USFDA has approved only four drugs viz. Donepezil, Rivastigmine, Memantine, and Galantamine for the treatment of AD. These drugs exhibit their neuroprotective effects either by inhibiting cholinesterase enzyme (ChE) or N-methyl-d-aspartate (NMDA) receptor. However, the conventional therapy "one target, one molecule" has failed to provide promising therapeutic effects due to the multifactorial nature of AD. This triggered the development of a novel strategy called Multi-Target Directed Ligand (MTDL) which involved designing one molecule that acts on multiple targets simultaneously. The present review discusses the detailed pathology involved in AD and the various MTDL design strategies bearing different heterocycles, in vitro and in vivo activities of the compounds, and their corresponding structure-activity relationships. This knowledge will allow us to identify and design more effective MTDLs for the treatment of AD.

Recent Advancements in the Treatment of Alzheimer's Disease: A Multitarget-directed Ligand Approach

Alzheimer's disease (AD) is a neurodegenerative disease and one of the leading causes of progressive dementia, affecting 50 million people worldwide. Many pathogenic processes, including amyloid β aggregation, tau hyperphosphorylation, oxidative stress, neuronal death, and deterioration of the function of cholinergic neurons, are associated with its progression. The one-compound-one-target treatment paradigm was unsuccessful in treating AD due to the multifaceted nature of Alzheimer's disease. The recent development of multitarget-directed ligand research has been explored to target the complementary pathways associated with the disease. We aimed to find the key role and progress of MTDLs in treating AD; thus, we searched for the past ten years of literature on "Pub- Med", "ScienceDirect", "ACS" and "Bentham Science" using the keywords neurodegenerative diseases, Alzheimer's disease, and multitarget-directed ligands. The literature was further filtered based on the quality of work and relevance to AD. Thus, this review highlights the current advancement and advantages of multitarget-directed ligands over traditional single-targeted drugs and recent progress in their development to treat AD.

Therapy and diagnosis of Alzheimer's disease: from discrete metal complexes to metal-organic frameworks

Alzheimer's disease (AD) is a neurodegenerative disorder affecting 44 million people worldwide. Although many issues (pathogenesis, genetics, clinical features, and pathological aspects) are still unknown, this disease is characterized by noticeable hallmarks such as the formation of β-amyloid plaques, hyperphosphorylation of tau proteins, the overproduction of reactive oxygen species, and the reduction of acetylcholine levels. There is still no cure for AD and the current treatments are aimed at regulating the cholinesterase levels, attenuating symptoms temporarily rather than preventing the AD progression. In this context, coordination compounds are regarded as a promissing tool in AD treatment and/or diagnosis. Coordination compounds (discrete or polymeric) possess several features that make them an interesting option for developing new drugs for AD (good biocompatibility, porosity, synergetic effects of ligand-metal, fluorescence, particle size, homogeneity, monodispersity, etc.). This review discusses the recent progress in the development of novel discrete metal complexes and metal-organic frameworks (MOFs) for the treatment, diagnosis and theragnosis of AD. These advanced therapies for AD treatment are organized according to the target: Aβ peptides, hyperphosphorylated tau proteins, synaptic dysfunction, and mitochondrial failure with subsequent oxidative stress.