Discovery of novel β-carboline derivatives as selective AChE inhibitors with GSK-3β inhibitory property for the treatment of Alzheimer's disease

Discovery of 6-amino pyridine clubbed heterocycles as potent dual GSK-3β/CK-1δ inhibitors for the treatment of Alzheimer's disease

Alzheimer's disease (AD) is a progressive and chronic neurodegenerative disorder progression through various kinases. Glycogen synthase kinase 3β (GSK-3β) and Casein Kinase-1δ (CK-1δ) have gained a lot of attention for its role in tau pathology. Utilizing a multitarget strategy, a series of 6-amino pyridine derivatives were developed as promising dual GSK-3β/CK-1δ inhibitors for the treatment of AD. This study involved the design, synthesis, and evaluation of novel 6-amino pyridine derivatives as dual GSK-3β/CK-1δ inhibitors exhibiting excellent biological activities. The in-vitro results indicated that most of compounds displayed promising activity against GSK-3β/CK-1δ. Among the tested compounds, 8d exhibited strong inhibitory activity against GSK-3β and CK-1δ, with IC₅₀ values of 0.77 ± 0.01 μM and 0.57 ± 0.12 μM, respectively. Notably, compound 8d significantly reduced tau hyperphosphorylated aggregates while demonstrating safety in SH-SY5Y neuroblastoma cell lines. ADME prediction results indicated that compound 8d adhered to Lipinski's rule of five and exhibited potential to permeate the blood-brain barrier (BBB). Molecular docking analysis revealed that this compound fits well within the ATP binding site, forming hydrogen bonds between its 6-amino pyridine ring with key amino acids, including Asp133 and Val135 in the hinge region of GSK-3β, as well as Leu85 of CK-1δ. These findings indicate that 6-amino pyridine derivatives have the potential to be effective dual-target candidates for AD.

Discovery and evaluation of novel Benzohydroxamic acid-indole derivatives as dual inhibitors of ADAM17 and HDAC2 with antitumor activity

Hepatocellular carcinoma (HCC) has garnered significant attention from researchers due to its high recurrence rate and invasive characteristics. The design of drugs with dual-target combined effects represents a promising strategy in cancer treatment. Our observations suggest that ADAM17 and HDAC may inhibit the unfavorable prognostic signaling pathway Notch1 in HCC through distinct mechanisms, thereby suppressing tumor cell proliferation and metastasis. Consequently, this study utilized the ADAM17 inhibitor ZLDI-8 as a lead compound and developed a series of dual ADAM17/HDAC2 inhibitors by integrating strategies such as backbone leaping and pharmacophore fusion. We assessed the anti-hepatocellular carcinoma activity of these compounds, focusing on their anti-proliferative, pro-apoptotic, and anti-metastatic properties. Notably, ZSNI-21 effectively inhibited the proliferation of Bel-7402 cells and demonstrated significant anti-metastatic capabilities against HCC-LM3 cells, with its targeting confirmed. Additionally, its in vivo safety was validated. To date, there have been no reports on dual ADAM17/HDAC2 inhibitors, marking this as a novel endeavor.

Bioactivities and Structure-Activity Relationships of Harmine and Its Derivatives: A Review

Natural products and their derivatives play a crucial role in treating various diseases. Harmine, a tricyclic β-carboline alkaloid isolated from the seeds of Peganum harmala L., has emerged as a promising therapeutic candidate owing to its multifaceted biological activities. Recent studies have further highlighted the enhanced therapeutic potential of harmine derivatives. To assess the current research landscape on harmine and its derivatives, we conducted a comprehensive analysis of studies published between 2019 and 2024 in scientific databases, such as PubMed, Web of Science, and Google Scholar. In this review, the possible applications of harmine and its derivatives were systematically illustrated, including biological activities, structure-activity relationships, and nanotechnology applications. Notably, the biological activities of harmine and its derivatives mainly contained antitumor, neuroprotective, antiparasitic, anti-inflammatory, and antidiabetic properties. In addition, structural modifications and the application of nanocarriers make harmine and its derivatives more druggable. The aim of this review is to summarize the recent advancements in harmine and its derivatives research, analyze emerging trends, and explore their clinical value.

Glycogen synthase kinase 3 (GSK3) inhibition: a potential therapeutic strategy for Alzheimer's disease

Alzheimer's disease (AD), the most common type of dementia among older adults, is a chronic neurodegenerative pathology that causes a progressive loss of cognitive functioning with a decline of rational skills. It is well known that AD is multifactorial, so there are many different pharmacological targets that can be pursued. According to estimates from the World Health Organization (WHO), 18 million individuals worldwide suffer from AD. Major initiatives to identify risk factors, enhance care giving, and conduct basic research to delay the beginning of AD were started by the USA, France, Germany, France, and various other nations. Widely recognized as a key player in the development and subsequent progression of AD pathogenesis, glycogen synthase kinase-3 (GSK-3) controls a number of crucial targets associated with neuronal degeneration. GSK-3 inhibition has been linked to reduced tau hyperphosphorylation, β-amyloid formation, and neuroprotective benefits in Alzheimer's disease. Lithium, the very first inhibitor of GSK-3β that was used therapeutically, has been successfully used for many years with remarkable results. A great variety of structurally varied strong GSK-3β blockers have been identified in recent years. The purpose of this thorough review is to cover the biological and structural elements of glycogen synthase kinase, as well as the medicinal chemistry aspects of GSK inhibitors that have been produced in recent years.

Resource distribution, pharmacological activity, toxicology and clinical drugs of β-Carboline alkaloids: An updated and systematic review

β-Carboline alkaloids are a broad class of indole alkaloids that were first isolated from Peganum harmala L., a traditional Chinese herbal remedy. β-Carboline alkaloids have been found to have many pharmacological activities, including anti-inflammatory, antioxidant, and anti-cancer properties. β-Carboline alkaloids have been studied, and nine therapeutic medications based on its structural skeleton have been utilized to treat a range of illnesses. These compounds' potent pharmacological action and high druggability have garnered a lot of interest. This review systematically summarized resource distribution, pharmacological activity, toxicology and clinical drugs of β-Carboline alkaloids. These alkaloids are mostly found in plants, particularly (Peganum harmala L.), although they are also present in food, bacteria, fungus, and animals. By inhibiting NF-κB, MAPKs, and PI3K-AKT multiple signal pathways, they demonstrate a wide range of pharmacological activities, including anti-inflammatory, oxidative, neurological, cancer, fungal, and leishmania pharmacological activity. Toxicology revealed that β-Carboline alkaloids can produce confusion, irritability, dyskinesia, nausea, vomiting, and audiovisual hallucinations in addition to stimulating the central nervous system and inhibiting metabolism. Clinical drugs based on β-Carboline alkaloids have been used for clinical treatment of arrhythmia, cerebrovascular diseases and dysfunction, hypertension, epilepsy, malaria and mydriasis diseases. It will prompt us to redefine β-Carboline alkaloids. For β-Carboline alkaloids that inspires pharmacological applications in medicine and the development of novel medications containing these alkaloids, it will be a useful resource.

Dual-target inhibitors based on acetylcholinesterase: Novel agents for Alzheimer's disease

Alzheimer's disease (AD) is the most common form of dementia among the elderly, accounting for 60 %-70 % of cases. At present, the pathogenesis of this condition remains unclear, but the hydrolysis of acetylcholine (ACh) is thought to play a role. Acetylcholinesterase (AChE) can break down ACh transmission from the presynaptic membrane and stop neurotransmitters' excitatory effect on the postsynaptic membrane, which plays a key role in nerve conduction. Acetylcholinesterase inhibitors (AChEIs) can delay the hydrolysis of acetylcholine (ACh), which represents a key strategy for treating AD. Due to its complex etiology, AD has proven challenging to treat. Various inhibitors and antagonists targeting key enzymes and proteins implicated in the disease's pathogenesis have been explored as potential therapeutic agents. These include Glycogen Synthase Kinase 3β (GSK-3β) inhibitors, β-site APP Cleaving Enzyme (BACE-1) inhibitors, Monoamine Oxidase (MAO) inhibitors, Phosphodiesterase inhibitors (PDEs), N-methyl--aspartic Acid (NMDA) antagonists, Histamine 3 receptor antagonists (H3R), Serotonin receptor subtype 4 (5-HT4R) antagonists, Sigma1 receptor antagonists (S1R) and soluble Epoxide Hydrolase (sEH) inhibitors. The drug development strategy of multi-target-directed ligands (MTDLs) offers unique advantages in the treatment of complex diseases. On the one hand, it can synergistically enhance the therapeutic efficacy of single-target drugs. On the other hand, it can also reduce the side effects. In this review, we discuss the design strategy of dual inhibitors based on acetylcholinesterase and the structure-activity relationship of these drugs.

Peganum harmala L. seed extract attenuates anxiety and depression in rats by reducing neuroinflammation and restoring the BDNF/TrkB signaling pathway and monoamines after exposure to chronic unpredictable mild stress

Depression is a mental disorder characterised by persistent low mood, anhedonia and cognitive impairment that affects an estimated 3.8% of the world's population, including 5% of adults. Peganum harmala L. (P. harmala) is a medicinal plant and has been reported to be effective against Alzheimer's disease, Parkinson's disease and depression. The present study was aimed to evaluate the behavioral and pharmacological effects of P. harmala seed extract in rats exposed to chronic unpredictable mild stress (CUMS) in vivo and to investigate the mechanism of action. CUMS-exposed rats were treated with P. harmala extract (75 and 150 mg/kg, i.p.) for 2 weeks. HPLC analysis was used to determine the concentration of harmaline and harmine alkaloids in the extract. Heavy metal analysis in seeds was performed by ICP-MS. Our results showed that P. harmala at the dose of 150 mg/kg significantly reduced the depressive-like behaviors in CUMS-exposed rats, as evidenced by increased sucrose consumption in the sucrose preference test (SPT), decreased immobility time in the forced swim test (FST) and plasma corticosterone levels, increased the time spent in open arms in the elevated plus maze (EPM), and improved memory and learning in the passive avoidance test (PAT). In addition, P. harmala decreased monoamine oxidase-A (MAO-A) levels, and increased serotonin (5-HT), dopamine (DA), and noradrenaline (NA) levels in the brains of rats exposed to CUMS. P. harmala decreased the expression of the pro-inflammatory transcription factor nuclear factor-κB (NF-κB), and increased the antioxidant nuclear factor erythroid 2-related factor 2 (Nrf2) in rat brain. Furthermore, P. harmala improved brain-derived neurotrophic factor (BDNF) and tropomyosin receptor kinase B (TrkB) protein expression in rat brain. In conclusion, P. harmala at a dose of 150 mg/kg is more effective in preventing depressive-like behavior in CUMS-exposed rats by improving neurotransmitter levels, reducing oxidative stress, suppressing neuroinflammation and activating the BDNF/TrkB pathway, all of which are important in the pathogenesis of depression.

Unraveling the mechanistic interplay of mediators orchestrating the neuroprotective potential of harmine

Neurodegenerative diseases (NDDs) encompass a range of conditions characterized by the specific dysfunction and continual decline of neurons, glial cells, and neural networks within the brain and spinal cord. The majority of NDDs exhibit similar underlying causes, including oxidative stress, neuroinflammation, and malfunctioning of mitochondria. Elevated levels of acetylcholinesterase (AChE) and butyrylcholinesterase (BChE), alongside decreased expression of brain-derived neurotrophic factor (BDNF) and glutamate transporter subtype 1 (GLT-1), constitute significant factors contributing to the pathogenesis of NDDs. Additionally, the dual-specificity tyrosine phosphorylation-regulated kinase 1 A (DYRK1A) gene has emerged as a significant target for the treatment of NDDs at the preclinical level. It significantly contributes to developmental brain defects, early onset neurodegeneration, neuronal loss, and dementia in Down syndrome. Moreover, an impaired ubiquitin-proteosome system (UPS) also plays a pathological role in NDDs. Malfunctioning of UPS leads to abnormal protein buildup or aggregation of α-synuclein. α-Synuclein is a highly soluble unfolded protein that accumulates in Lewy bodies and Lewy neurites in Parkinson's disease and other synucleinopathies. Recent research highlights the promising potential of natural products in combating NDDs relative to conventional therapies. Alkaloids have emerged as promising candidates in the fight against NDDs. Harmine is a tricyclic β-carboline alkaloid (harmala alkaloid) with one indole nucleus and a six-membered pyrrole ring. It is extracted from Banisteria caapi and Peganum harmala L. and exhibits diverse pharmacological properties, encompassing neuroprotective, antioxidant, anti-inflammatory, antidepressant, etc. Harmine has been reported to mediate its neuroprotective via reducing the level of inflammatory mediators, NADPH oxidase, AChE, BChE and reactive oxygen species (ROS). Whereas, it has been observed to increase the levels of BDNF, GLT-1 and anti-oxidant enzymes, along with protein kinase-A (PKA)-mediated UPS activation. This review aims to discuss the mechanistic interplay of various mediators involved in the neuroprotective effect of harmine.

Discovery of ZJCK-6-46: A Potent, Selective, and Orally Available Dual-Specificity Tyrosine Phosphorylation-Regulated Kinase 1A Inhibitor for the Treatment of Alzheimer's Disease

Targeting dual-specificity tyrosine phosphorylation-regulated kinase 1A (DYRK1A) has been verified to regulate the progression of tau pathology as a promising treatment for Alzheimer's disease (AD), while the research progress on DYRK1A inhibitors seemed to be in a bottleneck period. In this work, we identified 32 (ZJCK-6-46) as the most potential DYRK1A inhibitor (IC50 = 0.68 nM) through rational design, systematic structural optimization, and comprehensive evaluation. Compound 32 exhibited acceptable in vitro absorption, distribution, metabolism, and excretion (ADME) properties and significantly reduced the expression of p-Tau Thr212 in Tau (P301L) 293T cells and SH-SY5Y cells. Moreover, compound 32 showed favorable bioavailability, blood-brain barrier (BBB) permeability, and the potential of ameliorating cognitive dysfunction by obviously reducing the expression of phosphorylated tau and neuronal loss in vivo, which was deserved as a valuable molecular tool to reveal the role of DYRK1A in the pathogenesis of AD and to further promote the development of anti-AD drugs.

Discovery of novel quinolin-2-one derivatives as potential GSK-3β inhibitors for treatment of Alzheimer's disease: Pharmacophore-based design, preliminary SAR, in vitro and in vivo biological evaluation

Recently, glycogen synthase kinase-3β (GSK-3β) has been considered as a critical factor implicated in Alzheimer's disease (AD). In a previous work, a 3D pharmacophore model for GSK-3β inhibitors was created and the results suggested that derivative ZINC67773573, VIII, may provide a promising lead for developing novel GSK-3β inhibitors for the AD's treatment. Consequently, in this work, novel series of quinolin-2-one derivatives were synthesized and assessed for their GSK-3β inhibitory properties. In vitro screening identified three compounds: 7c, 7e and 7f as promising GSK-3β inhibitors. Compounds 7c, 7e and 7f were found to exhibit superior inhibitory effect on GSK-3β with IC50 value ranges between 4.68 ± 0.59 to 8.27 ± 0.60 nM compared to that of staurosporine (IC50 = 6.12 ± 0.74 nM). Considerably, compounds 7c, 7e and 7f effectively lowered tau hyperphosphorylated aggregates and proving their safety towards the SH-SY5Y and THLE2 normal cell lines. The most promising compound 7c alleviated cognitive impairments in the scopolamine-induced model in mice. Compound 7c's activity profile, while not highly selective, may provide a starting point and valuable insights into the design of multi-target inhibitors. According to the ADME prediction results, compounds 7c, 7e and 7f followed Lipinski's rule of five and could almost permeate through the BBB. Molecular docking simulations showed that these compounds are well accommodated in the ATP binding site interacting by its quinoline-2-one ring through hydrogen bonding with the key amino acids Asp133 and Val135 at the hinge region. The findings of this study suggested that these new compounds may have potential as anti-AD drugs targeting GSK-3β.

Design, Synthesis, and Biological Evaluation of Novel Tetrahydroacridin Hybrids with Sulfur-Inserted Linkers as Potential Multitarget Agents for Alzheimer's Disease

Alzheimer's disease (AD) is a complex neurodegenerative disease that can lead to the loss of cognitive function. The progression of AD is regulated by multiple signaling pathways and their associated targets. Therefore, multitarget strategies theoretically have greater potential for treating AD. In this work, a series of new hybrids were designed and synthesized by the hybridization of tacrine (4, AChE: IC50 = 0.223 μM) with pyrimidone compound 5 (GSK-3β: IC50 = 3 μM) using the cysteamine or cystamine group as the connector. The biological evaluation results demonstrated that most of the compounds exhibited moderate to good inhibitory activities against acetylcholinesterase (AChE) and glycogen synthase kinase 3β (GSK-3β). The optimal compound 18a possessed potent dual AChE/GSK-3β inhibition (AChE: IC50 = 0.047 ± 0.002 μM, GSK-3β: IC50 = 0.930 ± 0.080 μM). Further molecular docking and enzymatic kinetic studies revealed that this compound could occupy both the catalytic anionic site and the peripheral anionic site of AChE. The results also showed a lack of toxicity to SH-SY5Y neuroblastoma cells at concentrations of up to 25 μM. Collectively, this work explored the structure-activity relationships of novel tetrahydroacridin hybrids with sulfur-inserted linkers, providing a reference for the further research and development of new multitarget anti-AD drugs.

Dual-target inhibitors of cholinesterase and GSK-3β to modulate Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease that affects over 55 million patients worldwide. Most of the approved small-molecule drugs for AD have been designed to tackle a single pathological hallmark, such as cholinergic dysfunction or amyloid toxicity, and thus may not fully address the multifactorial nature of the disease. Inhibition of both cholinesterase and glycogen synthase kinase-3β (GSK-3β) has emerged as a promising strategy to modulate AD. However, the dual inhibition of these two targets posts challenges in molecular design: issues related to target engagements and biopharmaceutical properties in particular must be overcome. In this review, we discuss the physiopathological roles and structures of cholinesterase and GSK-3β as well as recently reported dual-target inhibitors. We critically evaluate the current status of the discovery of dual-target inhibitors of cholinesterase and GSK-3β, and highlight further perspectives.

Targeting glycogen synthase kinase-3β for Alzheimer's disease: Recent advances and future Prospects

Senile plaques induced by β-amyloid (Aβ) abnormal aggregation and neurofibrillary tangles (NFT) caused by tau hyperphosphorylation are important pathological manifestations of Alzheimer's disease (AD). Glycogen synthase kinase-3 (GSK-3) is a conserved kinase; one member GSK-3β is highly expressed in the AD brain and involved in the formation of NFT. Hence, pharmacologically inhibiting GSK-3β activity and expression is a good approach to treat AD. As summarized in this article, multiple GSK-3β inhibitors has been comprehensively summarized over recent five years. However, only lithium carbonate and Tideglusib have been studied in clinical trials of AD. Besides ATP-competitive and non-ATP-competitive inhibitors, peptide inhibitors, allosteric inhibitors and other types of inhibitors have gradually attracted more interest. Moreover, considering the close relationship between GSK-3β and other targets involved in cholinergic hypothesis, Aβ aggregation hypothesis, tau hyperphosphorylation hypothesis, oxidative stress hypothesis, neuro-inflammation hypothesis, etc., diverse multifunctional molecules and multi-target directed ligands (MTDLs) have also been disclosed. We hope that these recent advances and critical perspectives will facilitate the discovery of safe and effective GSK-3β inhibitors for AD treatment.

Research progress of natural products and their derivatives against Alzheimer's disease

Alzheimer's disease (AD), a persistent neurological dysfunction, has an increasing prevalence with the aging of the world and seriously threatens the health of the elderly. Although there is currently no effective treatment for AD, researchers have not given up, and are committed to exploring the pathogenesis of AD and possible therapeutic drugs. Natural products have attracted considerable attention owing to their unique advantages. One molecule can interact with multiple AD-related targets, thus having the potential to be developed in a multi-target drug. In addition, they are amenable to structural modifications to increase interaction and decrease toxicity. Therefore, natural products and their derivatives that ameliorate pathological changes in AD should be intensively and extensively studied. This review mainly presents research on natural products and their derivatives for the treatment of AD.

β-Carboline Alkaloids Resist the Aggregation and Cytotoxicity of Human Islet Amyloid Polypeptide

β-Carboline alkaloids have a variety of pharmacological activities, such as antitumor, antibiosis and antidiabetes. Harmine and harmol are two structurally similar β-carbolines that occur in many medicinal plants. In this work, we chose harmine and harmol to impede the amyloid fibril formation of human islet amyloid polypeptide (hIAPP) associated with type 2 diabetes mellitus (T2DM), by a series of physicochemical and biochemical methods. The results indicate that harmine and harmol effectively prevent peptide fibril formation and alleviate toxic oligomer species. In addition, both small molecules exhibit strong binding affinities with hIAPP mainly through hydrophobic and hydrogen bonding interactions, thus reducing the cytotoxicity induced by hIAPP. Their distinct binding pattern with hIAPP is closely linked to the molecular configuration of the two small molecules, affecting their ability to impede peptide aggregation. The study is of great significance for the application and development of β-carboline alkaloids against T2DM.

Designing of new tetrahydro-β-carboline-based ABCG2 inhibitors using 3D-QSAR, molecular docking, and DFT tools

Human ATP-binding cassette superfamily G member 2 (ABCG2) protein is a member of the ABC transporter family, which is responsible for multidrug resistance (MDR) in cancerous cells. MDR reduces the effectiveness of chemotherapy in breast cancer, which is one of the leading causes of death in women globally. MDR in cancer cells is one of the immediate signs of progression of resistance; thus, various anticancer drugs can be designed. To reduce MDR, we utilized the tetrahydro-β-carboline (THβC) compound library. We accomplished a three-dimensional quantitative structure-activity relationship (3D-QSAR), scaffold hopping to design a new library of compounds of THβC, and further molecular docking, induced-fit docking (IFD), molecular mechanics energies combined with generalized born and surface area continuum solvation (MM-GBSA), drug-like features, ADMET properties, and density functional theory (DFT) studies were performed. From these studies, the best 3D-QSAR model (r2 = 0.99, q2 = 0.92) was found, and the necessity of electrostatic, steric, and hydrophobic field effects were determined that could modulate bioactivity. Moreover, based on electrostatic, steric, and hydrophobic field notations, new THβC derivatives (3409) were designed. These findings might provide new insight for researchers to perform in vitro and in vivo studies for better antagonists against MDR in treating breast cancer.Communicated by Ramaswamy H. Sarma.

Synthesis and biological evaluation of thieno[3,2-c]pyrazol-3-amine derivatives as potent glycogen synthase kinase 3β inhibitors for Alzheimer's disease

Glycogen synthase kinase 3β (GSK-3β) catalyses the hyperphosphorylation of tau protein in the Alzheimer's disease (AD) pathology. A series of novel thieno[3,2-c]pyrazol-3-amine derivatives were designed and synthesised and evaluated as potential GSK-3β inhibitors by structure-guided drug rational design approach. The thieno[3,2-c]pyrazol-3-amine derivative 16b was identified as a potent GSK-3β inhibitor with an IC₅₀ of 3.1 nM in vitro and showed accepted kinase selectivity. In cell levels, 16b showed no toxicity on the viability of SH-SY5Y cells at the concentration up to 50 μM and targeted GSK-3β with the increased phosphorylated GSK-3β at Ser9. Western blot analysis indicated that 16b decreased the phosphorylated tau at Ser396 in a dose-dependent way. Moreover, 16b effectively increased expressions of β-catenin as well as the GAP43, N-myc, and MAP-2, and promoted the differentiated neuronal neurite outgrowth. Therefore, the thieno[3,2-c]pyrazol-3-amine derivative 16b could serve as a promising GSK-3β inhibitor for the treatment of AD.

Comprehensive review of α-carboline alkaloids: Natural products, updated synthesis, and biological activities

α-carboline (9H-pyrido[2,3-b]indole), contains a pyridine ring fused with an indole backbone, is a promising scaffold for medicinal chemistry. In recent decades, accumulating evidence shows that α-carboline natural products and their derivatives possess diverse bioactivities. However, hitherto, there is no comprehensive review to systematically summarize this important class of alkaloids. In this perspective, this paper represents the first review to provide a comprehensive description of α-carbolines including natural products, updated literature of synthesis, and their diverse biological activities. Their biological activities including antitumor, anti-microbial, anti-Alzheimer’s disease, anti-atherosclerosis, and antioxidant activities were hilighted. And the targets and the main structure activity relationships (SARs) will be presented. Finally, challenges and future directions of this class of compounds will be discussed. This review will be helpful in understanding and encouraging further exploration for this group of alkaloids.

Design, synthesis and biological evaluation of novel coumarin derivatives as multifunctional ligands for the treatment of Alzheimer's disease

Multi-targeted directed ligands (MTDLs) are emerging as promising Alzheimer's disease (AD) therapeutic possibilities. Coumarin is a multifunctional backbone with extensive bioactivity that has been utilized to develop innovative anti-neurodegenerative properties and is a desirable starting point for the construction of MTDLs. Herein, we explored and synthesized a series of novel coumarin derivatives and assessed their inhibitory effects on cholinesterase (AChE, BuChE), GSK-3β, and BACE1. Among these compounds, compound 30 displayed the multifunctional profile of targeting the AChE (IC₅₀ = 1.313 ± 0.099 μM) with a good selectivity over BuChE (SI = 24.623), GSK-3β (19.30% inhibition at 20 μM), BACE1 (IC₅₀ = 1.227 ± 0.112 μM), along with moderate HepG2 cytotoxicity, SH-SY5Y cytotoxicity, low HL-7702 cytotoxicity, as well as good blood-brain barrier (BBB) permeability. Kinetic and docking studies indicated that compound 30 was a competitive AChE inhibitor. Furthermore, acute toxicity experiments revealed that it was non-toxic at a dosage of 1000 mg/kg. The ADME prediction results indicate that 30 has acceptable physicochemical properties. Collectively, these findings demonstrated that compound 30 would be a potential multifunctional candidate for AD therapy.

Discovery of novel and potent tacrine derivatives as CDK2 inhibitors

After optimization of the lead compound, ZLHT-7, a compound with 10-fold higher selectivity for CDK2 over CDK9, was discovered.