The Magic of Crystal Structure-Based Inhibitor Optimization: Development of a Butyrylcholinesterase Inhibitor with Picomolar Affinity and in Vivo Activity

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.

Novel 1,2,4-triazole derivatives containing the naphthalene moiety as selective butyrylcholinesterase inhibitors: Design, synthesis, and biological evaluation

Butyrylcholinesterase (BChE) is considered a promising therapeutic target for treating Alzheimer's disease due to the increase in the levels and activity of BChE in the late stage of the disease. In this study, a series of novel 1,2,4-triazole derivatives bearing the naphthalene moiety linked to the benzothiazole, thiazole, and phenyl scaffolds via amid chain were designed and synthesized as potential and selective BChE inhibitors. The results of the inhibitory activity studies revealed that most of these compounds exhibited significant inhibitor potency on BChE. Compounds 35a (0.025 ± 0.01 μM) and 37a (0.035 ± 0.01 μM) displayed the most potent inhibitory activity, with excellent selectivity against BChE over acetylcholinesterase (SIBChE, 23,686 and 16,936, respectively) among the target compounds. The kinetics studies revealed that these compounds behaved with noncompetitive BChE inhibitors. Molecular docking studies indicated that 35a and 37a fit well into the active side of BChE. In addition, 35a and 37a also had the lowest cytotoxicity for human neuroblastoma cells (SH-SY5Y), potential antioxidant capacity, moderate inhibition potency on amyloid-β1-42 aggregation, and significant neuroprotective effect against SH-SY5Y cell injury induced by H2O2 and amyloid-β1-42. All results suggest that these compounds might be considered as promising new lead compounds in the drug discovery process for the treatment of late-stage Alzheimer's disease.

Novel multifunctional tacrine-donepezil hybrids against Alzheimer's disease: Design synthesis and bioactivity studies

A series of tacrine-donepezil hybrids were synthesized as potential multifunctional anti-Alzheimer's disease (AD) compounds. For this purpose, tacrine and the benzylpiperidine moiety of donepezil were fused with a hydrazone group to achieve a small library of tacrine-donepezil hybrids. In agreement with the design, all compounds showed inhibitory activity toward both acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) with IC50 values in the low micromolar range. Kinetic studies on the most potent cholinesterase (ChE) inhibitors within the series showed a mixed-type inhibition mechanism on both enzymes. Also, the docking studies indicated that the compounds inhibit ChEs by dual binding site (DBS) interactions. Notably, tacrine-donepezil hybrids also exhibited significant neuroprotection against H2O2-induced cell death in a differentiated human neuroblastoma (SH-SY5Y) cell line at concentrations close to their IC50 values on ChEs and showed high to medium blood-brain barrier (BBB) permeability on human cerebral microvascular endothelial cells (HBEC-5i). Besides, the compounds do not cause remarkable toxicity in a human hepatocellular carcinoma cell line (HepG2) and SH-SY5Y cells. Additionally, the compounds were predicted to also have good bioavailability. Among the tested compounds, H4, H16, H17, and H24 stand out with their biological profile. Taken together, the proposed novel tacrine-donepezil scaffold represents a promising starting point for the development of novel anti-ChE multifunctional agents against AD.

Synthesis and biological studies of pyrimidine derivatives targeting metabolic enzymes

Novel synthesized pyrimidine derivatives were investigated against carbonic anhydrase isoenzymes I and II (hCA I and II), acetylcholinesterase (AChE), butyrylcholinesterase (BChE), α-glycosidase, and aldose reductase (AR) enzymes associated with some common diseases such as epilepsy, glaucoma, Alzheimer's disease, diabetes, and neuropathy. When the results were examined, novel synthesized pyrimidine derivatives were found to have effective inhibition abilities toward the metabolic enzymes. IC50 values and Ki values were calculated for each pyrimidine derivative and compared to positive controls. The synthesized novel pyrimidine derivatives exhibited Ki values in the range of 39.16 ± 7.70-144.62 ± 26.98 nM against hCA I, 18.21 ± 3.66-136.35 ± 21.48 nM toward hCA II, which is associated with different pathological and physiological processes, 33.15 ± 4.85-52.98 ± 19.86 nM on AChE, and 31.96 ± 8.24-69.57 ± 21.27 nM on BChE. Also, Ki values were determined in the range of 17.37 ± 1.11-253.88 ± 39.91 nM against α-glycosidase and 648.82 ± 53.74-1902.58 ± 98.90 nM toward AR enzymes. Within the scope of the study, the inhibition types of the novel synthesized pyrimidine derivatives were evaluated.

Indole-Based Compounds in the Development of Anti-Neurodegenerative Agents

Neurodegeneration is a gradual decay process leading to the depletion of neurons in both the central and peripheral nervous systems, ultimately resulting in cognitive dysfunctions and the deterioration of brain functions, alongside a decline in motor skills and behavioral capabilities. Neurodegenerative disorders (NDs) impose a substantial socio-economic strain on society, aggravated by the advancing age of the world population and the absence of effective remedies, predicting a negative future. In this context, the urgency of discovering viable therapies is critical and, despite significant efforts by medicinal chemists in developing potential drug candidates and exploring various small molecules as therapeutics, regrettably, a truly effective treatment is yet to be found. Nitrogen heterocyclic compounds, and particularly those containing the indole nucleus, which has emerged as privileged scaffold, have attracted particular attention for a variety of pharmacological applications. This review analyzes the rational design strategy adopted by different research groups for the development of anti-neurodegenerative indole-based compounds which have the potential to modulate various molecular targets involved in NDs, with reference to the most recent advances between 2018 and 2023.

Practical Three-Component Regioselective Synthesis of Drug-Like 3-Aryl(or heteroaryl)-5,6-dihydrobenzo[h]cinnolines as Potential Non-Covalent Multi-Targeting Inhibitors To Combat Neurodegenerative Diseases

Neurodegenerative diseases (NDs) are one of the prominent health challenges facing contemporary society, and many efforts have been made to overcome and (or) control it. In this research paper, we described a practical one-pot two-step three-component reaction between 3,4-dihydronaphthalen-1(2H)-one (1), aryl(or heteroaryl)glyoxal monohydrates (2a-h), and hydrazine monohydrate (NH2NH2•H2O) for the regioselective preparation of some 3-aryl(or heteroaryl)-5,6-dihydrobenzo[h]cinnoline derivatives (3a-h). After synthesis and characterization of the mentioned cinnolines (3a-h), the in silico multi-targeting inhibitory properties of these heterocyclic scaffolds have been investigated upon various Homo sapiens-type enzymes, including hMAO-A, hMAO-B, hAChE, hBChE, hBACE-1, hBACE-2, hNQO-1, hNQO-2, hnNOS, hiNOS, hPARP-1, hPARP-2, hLRRK-2(G2019S), hGSK-3β, hp38α MAPK, hJNK-3, hOGA, hNMDA receptor, hnSMase-2, hIDO-1, hCOMT, hLIMK-1, hLIMK-2, hRIPK-1, hUCH-L1, hPARK-7, and hDHODH, which have confirmed their functions and roles in the neurodegenerative diseases (NDs), based on molecular docking studies, and the obtained results were compared with a wide range of approved drugs and well-known (with IC50, EC50, etc.) compounds. In addition, in silico ADMET prediction analysis was performed to examine the prospective drug properties of the synthesized heterocyclic compounds (3a-h). The obtained results from the molecular docking studies and ADMET-related data demonstrated that these series of 3-aryl(or heteroaryl)-5,6-dihydrobenzo[h]cinnolines (3a-h), especially hit ones, can really be turned into the potent core of new drugs for the treatment of neurodegenerative diseases (NDs), and/or due to the having some reactionable locations, they are able to have further organic reactions (such as cross-coupling reactions), and expansion of these compounds (for example, with using other types of aryl(or heteroaryl)glyoxal monohydrates) makes a new avenue for designing novel and efficient drugs for this purpose.

The pharmacological properties of Gypsophila eriocalyx: The endemic medicinal plant of northern central Turkey

The aim of this study is to evaluate and compare the biological properties of different extracts (methanol, ethanol, and water) obtained from Gypsophila eriocalyx (G. eriocalyx), a medicinal plant traditionally used in Turkey. The components of different extracts were defined using the GC-MS method. The effects of G. eriocalyx extracts on cell proliferation, apoptosis, and cell cycle arrest in MDA-MB-231 breast cancer as well as in vitro antioxidant, enzyme inhibition, and antimicrobial activities were investigated. In accordance with the results obtained, although ethanol and methanol extracts of G. eriocalyx show higher antioxidant activity than G. eriocalyx water extract, enzyme inhibition activities of the extracts were not found to be significant compared to the reference drug. The methanol and ethanol extract of G. eriocalyx exhibited moderate antimicrobial activity against Staphylococcus aureus and methanol extract showed significant antimicrobial activity against Bacillus cereus. In addition, both extracts significantly inhibited cell viability in a dose-dependent manner in breast cancer cells. The cell growth inhibition by methanol and ethanol extracts induced S phase cell-cycle arrest and apoptosis in MDA-MB-231 cells. Lastly, in order to compare the activities of the chemicals found in Gypsophila eriocalyx plant extract, their activities against various proteins that are breast cancer protein (PDB ID:1A52 and 1JNX), antioxidant protein (PDB ID: 1HD2), AChE enzyme protein (PDB ID: 4M0E), BChE enzyme protein (PDB ID: 5NN0), and Escherichia coli protein (PDB ID: 4PRV)were compared. Then, ADME/T analysis calculations were made to examine the effects of molecules with high activity on human metabolism. Eventually, G. eriocalyx is thought to be a potent therapeutic herb that can be considered as an alternative and functional therapy for the management of diseases of a progressive nature related to oxidative damage such as infection, diabetes, cancer, and Alzheimer's disease.

Design, synthesis, and activity evaluation of novel multitargeted l-tryptophan derivatives with powerful antioxidant activity against Alzheimer's disease

Alzheimer's disease (AD) is a multifactorial neurological disease, and the multitarget directed ligand (MTDL) strategy may be an effective approach to delay its progression. Based on this strategy, 27 derivatives of l-tryptophan, 3a-1-3d-1, were designed, synthesized, and evaluated for their biological activity. Among them, IC50 (inhibitor concentration resulting in 50% inhibitory activity) values of compounds 3a-18 and 3b-1 were 0.58 and 0.44 μM for human serum butyrylcholinesterase (hBuChE), respectively, and both of them exhibited more than 30-fold selectivity for human serum acetylcholinesterase. Enzyme kinetics studies showed that these two compounds were mixed inhibitors of hBuChE. In addition, these two derivatives possessed extraordinary antioxidant activity in OH radical scavenging and oxygen radical absorption capacity fluorescein assays. Meanwhile, these compounds could also prevent β-amyloid (Aβ) self-aggregation and possessed low toxicity on PC12 and AML12 cells. Molecular modeling studies revealed that these two compounds could interact with the choline binding site, acetyl binding site, and peripheral anionic site to exert submicromolar BuChE inhibitory activity. In the vitro blood-brain barrier permeation assay, compounds 3a-18 and 3b-1 showed enough blood-brain barrier permeability. In drug-likeness prediction, compounds 3a-18 and 3b-1 showed good gastrointestinal absorption and a low risk of human ether-a-go-go-related gene toxicity. Therefore, compounds 3a-18 and 3b-1 are potential multitarget anti-AD lead compounds, which could work as powerful antioxidants with submicromolar selective inhibitory activity for hBuChE as well as prevent Aβ self-aggregation.

Discovery, Structure-Based Modification, In Vitro, In Vivo, and In Silico Exploration of m-Sulfamoyl Benzoamide Derivatives as Selective Butyrylcholinesterase Inhibitors for Treating Alzheimer's Disease

For the potential therapy of Alzheimer's disease (AD), butyrylcholinesterase (BChE) has gradually gained worldwide interest in the progression of AD. This study used a pharmacophore-based virtual screening (VS) approach to identify Z32439948 as a new BChE inhibitor. Aiding by molecular docking and molecular dynamics, essential binding information was disclosed. Specifically, a subpocket was found and structure-guided design of a series of novel compounds was conducted. Derivatives were evaluated in vitro for cholinesterase inhibition and physicochemical properties (BBB, log P, and solubility). The investigation involved docking, molecular dynamics, enzyme kinetics, and surface plasmon resonance as well. The study highlighted compounds 27a (hBChE IC50 = 0.078 ± 0.03 μM) and (R)-37a (hBChE IC50 = 0.005 ± 0.001 μM) as the top-ranked BChE inhibitors. These compounds showed anti-inflammatory activity and no apparent cytotoxicity against the human neuroblastoma (SH-SY5Y) and mouse microglia (BV2) cell lines. The most active compounds exhibited the ability to improve cognition in both scopolamine- and Aβ1-42 peptide-induced cognitive deficit models. They can be promising lead compounds with potential implications for treating the late stage of AD.

Optimizing drug-like properties of selective butyrylcholinesterase inhibitors for cognitive improvement: Enhancing aqueous solubility by disrupting molecular plane

Most recently, worldwide interest in butyrylcholinesterase (BChE) as a potential target for treating Alzheimer's disease (AD) has increased. In this study, the previously obtained selective BChE inhibitors with benzimidazole-oxadiazole scaffold were further structurally modified to increase their aqueous solubility and pharmacokinetic (PK) characteristics. S16-1029 showed improved solubility (3280 μM, upgraded by 14 times) and PK parameters, including plasma exposure (AUC0-inf = 1729.95 ng/mL*h, upgraded by 2.6 times) and oral bioavailability (Fpo = 48.18%, upgraded by 2 times). S16-1029 also displayed weak or no inhibition against Cytochrome P450 (CYP450) and human ether a-go-go related gene (hERG) potassium channel. In vivo experiments on tissue distribution revealed that S16-1029 could cross the blood-brain barrier (BBB) and reach the central nervous system (CNS). In vivo cognitive improvement efficacy and good in vitro target inhibitory activity (eqBChE IC50 = 11.35 ± 4.84 nM, hBChE IC50 = 48.1 ± 11.4 nM) were also assured. The neuroprotective effects against several AD pathology characteristics allowed S16-1029 to successfully protect the CNS of progressed AD patients. According to the findings of this study, altering molecular planarity might be a viable strategy for improving the drug-like property of CNS-treating drugs.

A biochemistry-oriented drug design: synthesis, anticancer activity, enzymes inhibition, molecular docking studies of novel 1,2,4-triazole derivatives

In this study, we researched the reactions of 5-(5-bromofuran-2-yl)-4-methyl-1,2,4-triazole-3-thiol and 5-thiophene-(3-ylmethyl)-4R-1,2,4-triazole-3-thiols with some halogen-containing compounds, a number of new compounds were synthesized (1.1-1.5 and 2.1-2.8). These compounds showed excellent to good inhibitory activities on acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzymes. For obtaining the effects of these compounds on AChE and BChE enzymes were determined spectrophotometrically according to Ellman. IC50 values of these enzymes were ranging between 1.63 and 17.68 nM for AChE and 8.71 and 84.02 nM for BChE. After, prostate cancer is the second leading cause of cancer-related mortality for men over the age of 65 in developed countries. Current treatment options remain limited in the treatment of advanced-stage prostate cancer leading to biochemical recurrence in almost 40% of the patients. Therefore, there is an urgent need for development of novel therapeutic tools for treatment of prostate cancer patients. In this study, we aimed at analyzing the potential of all compounds against prostate cancer cells. We found that, of the tested compounds, 2.1, 2.2 and 2.3 showed significant cytotoxic activities against PC3 prostate cancer cells, although their effect on the viability of normal prostate cells was limited. These findings suggest their selective targeting potential for prostate cancer cells and offer them as candidate therapeutic agents against prostate cancer. The inhibitory activities of some chemical compounds, such as (1.1-1.5 and 2.1-2.8) were assessed by performing the molecular docking study in the presence of AChE, BChE and prostate cancer protein. MM/GBSA methods are calculated binding free energy. Finally, ADME/T analysis was performed to examine the drug properties of the 13 studied molecules.Communicated by Ramaswamy H. Sarma.

Development of novel salicylic acid-donepezil-rivastigmine hybrids as multifunctional agents for the treatment of Alzheimer's disease

Alzheimer's disease (AD) is a chronic, progressive brain degenerative disease that is common in the elderly. So far, there is no effective treatment. The multi-target-directed ligands (MTDLs) strategy has been recognised as the most promising approach due to the complexity of the pathogenesis of AD. Herein, novel salicylic acid-donepezil-rivastigmine hybrids were designed and synthesised. The bioactivity results exhibited that 5a was a reversible and selective eqBChE inhibitor (IC₅₀ = 0.53 μM), and the docking provided the possible mechanism. Compound 5a also displayed potential anti-inflammatory effects and significant neuroprotective effect. Moreover, 5a exhibited favourable stabilities in artificial gastrointestinal solution and plasma. Finally, 5a demonstrated potential cognitive improvement in scopolamine-induced cognitive dysfunction. Hence, 5a was a potential multifunctional lead compound against AD.

Design, synthesis, biological evaluation and molecular docking of cyclic biguanidine compounds as cholinesterase inhibitors

A series of cyclic biguanidine derivatives (E01-E16) was designed, synthesized, characterized by FTIR, NMR, elemental analysis and evaluated as cholinesterase [acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE)] inhibitory effects for the treatment of Alzheimer's disease (AD). The cyclic biguanidine derivatives (E01-E16) were obtained as hydrochloride salt from one-pot reaction of 2-cyanoguanidine, p-substitute aniline derivatives and cyclohexanone/4-ethylcyclohexanone in the acidic medium. The crystal structures of compounds E13 and E16 were determined by XRD studies. The in vitro acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibitory assessment of the compounds revealed that compounds showed considerable inhibitory activity. The substitute groups on the phenyl rings have an impact on the inhibitory activity of the compounds. Compound E08, containing an ester group on the phenyl ring, showed the highest inhibitory activity against BuChE (IC50: 97.97 ± 0.13 µM) compared to other compounds. According to the docking result, compound E08 exhibited higher binding affinity (-10.17 kcal/mol) against BuChE than the standard drug tacrine (-7.02 kcal/mol). Compound E08 was orientated towards the active site of the enzyme BuChE.Communicated by Ramaswamy H. Sarma.

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

A series of novel quinoline-O-carbamate derivatives was rationally designed for treating Alzheimer's disease (AD) by multi-target-directed ligands (MTDLs) strategy. The target compounds were synthesised and evaluated by AChE/BuChE inhibition and anti-inflammatory property. The in vitro activities showed that compound 3f was a reversible dual eeAChE/eqBuChE inhibitor with IC₅₀ values of 1.3 µM and 0.81 µM, respectively. Moreover, compound 3f displayed good anti-inflammatory property by decreasing the production of IL-6, IL-1β and NO. In addition, compound 3f presented significant neuroprotective effect on Aβ_25-35-induced PC12 cell injury. Furthermore, compound 3f presented good stabilities in artificial gastrointestinal fluids, liver microsomes in vitro and plasma. Furthermore, compound 3f could improve AlCl₃-induced zebrafish AD model by increasing the level of ACh. Therefore, compound 3f was a promising multifunctional agent for the treatment of AD.

Synthesis of indole derivatives as Alzheimer inhibitors and their molecular docking study

Acetylcholinesterase prevails in the healthy brain, with butyrylcholinesterase reflected to play a minor role in regulating brain acetylcholine (ACh) levels. However, BuChE activity gradually increases in patients with (AD), while AChE activity remains unaffected or decays. Both enzymes therefore represent legitimate therapeutic targets for ameliorating the cholinergic deficit considered to be responsible for the declines in cognitive, behavioural, and global functioning characteristic of AD. Current study described the synthesis of indole-based sulfonamide derivatives (1-23) and their biological activity. Synthesis of these scaffolds were achieved by mixing chloro-substituted indole bearing amine group with various substituted benzene sulfonyl chloride in pyridine, under refluxed condition to obtained desired products. All products were then evaluated for AchE and BuchE inhibitory potential compare with positive Donepezil as standard drug for both AchE and BchE having IC50 = 0.016 ± 0.12 and 0.30 ± 0.010 μM respectively. In this regard analog 9 was found potent having IC50 value 0.15 ± 0.050 μM and 0.20 ± 0.10 for both AchE and BuChE respectively. All other derivatives also found with better potential. All compounds were characterized by various techniques such as 1H, 13C-NMR and HREI-MS. In addition, biological activity was maintained to explore the bioactive nature of scaffolds and their protein-ligand interaction (PLI) was checked through molecular docking study.Communicated by Ramaswamy H. Sarma.

Synthesis, in silico and in vitro studies of hydrazide-hydrazone imine derivatives as potential cholinesterase inhibitors

A series of hydrazide-hydrazone imine derivative compounds (3a-k) were synthesized and their structures characterized using FTIR, 1 H, and 13 C (NMR) spectroscopic methods. In addition, molecular structures of compounds 3a, 3d, and 3g were elucidated by X-ray diffraction technique. In vitro inhibition activities of hydrazide-hydrazone imine derivatives against acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) were investigated. Compound 3i (IC50  = 2.01 μM) exhibited the best inhibitory activity against AChE, comparable to the control Galantamine (IC50  = 2.60 μM). Against BChE, compound 3h (IC50  = 2.83 μM) showed the best inhibitory property which is higher control Galantamine (IC50  = 3.70 μM). The Ki values of compound 3i (Ki = 0.63 μM) and compound 3h (Ki = 0.94 μM) that have the strongest inhibitory potential were determined against AChE and BChE, respectively. According to the docking result, the most stable conformation of AChE and compound 3i showed that it has a binding affinity of -10.82 kcal/moL. The binding affinity of the most stable conformation formed by BChE and compound 3h is -8.60 kcal/moL. Finally, in silico results and pharmacokinetic parameters of ADME showed that these compounds have good oral bioavailability properties.

Plant Regulation Functions of Novel Phthalimide Compounds Based on AtPYL2

Novel agents contain the structure of phthalimide, which has antibacterial, insecticidal, and herbicidal activities. Recently, studies reported that these compounds can bind to plant hormone receptors and play important regulatory roles. In this study, the functions of agents were studied with in vitro and in vivo assays. The abscisic acid (ABA) receptor pyrabactin resistant-like 2 (PYL2) protein in Arabidopsis thaliana was expressed, purified, and crystallized; the analysis results of the crystal structure showed three AtPYL2 subunits in each asymmetric unit. The affinity of compounds Z1-Z11 to the AtPYL2 protein was tested by microscale thermophoresis (MST) and then verified by isothermal titration calorimetry (ITC). Furthermore, the binding pockets were found using molecular docking to verify the target relationships. Relevant in vivo assays for seed germination and a root growth assay were conducted, with the plant samples being treated with target compounds. The results show that the compounds Z3, Z5, and Z10 target AtPYL2 and that the dissociation constants for binding by MST were 3.59, 3.54, and 3.97 μmol/L, respectively, among them, and the molecular docking results showed that compounds Z3, Z5, and Z10 formed hydrophobic interactions with amino acid residues through hydrogen or halogen bonding. This highlights their potential as an ABA receptor protein agonist. On the other hand, in vivo, compounds Z3, Z5, and Z10 had different inhibitory effects on seed germination, with compound Z5 inhibiting the root growth of A. thaliana and compound Z10 affecting root growth. In conclusion, these compounds could regulate plant growth and could be further developed as new plant-regulating agents.

Novel bis-ureido-substituted sulfaguanidines and sulfisoxazoles as carbonic anhydrase and acetylcholinesterase inhibitors

To discover alternative substances to compounds used to treat many diseases, especially treating Alzheimer's disease (AD) and Parkinson's disease targeting carbonic anhydrase (hCA) and acetylcholinesterase (AChE) enzymes, is important. For this purpose, a series of novel bis-ureido-substituted sulfaguanidine (SG1-4) and sulfisoxazole (SO1-4) derivatives were synthesized, and their inhibitory capacities were screened against hCA isoenzymes (hCA I and II) and AChE. Possible binding mechanisms of inhibitors to the active site were elucidated by in silico studies, and the results were supported by in vitro results. Moreover, the percent radical scavenging capacities of the derivatives were also evaluated. The derivatives (SG1-4 and SO1-4) were more effective against hCAs compared to standard drug acetazolamide (KI values of 98.28-439.17 nM for hCA I and II, respectively) and exhibited the highest inhibition with the KIs in the ranges of 2.54 ± 0.50-41.02 ± 7.52 nM for hCA I, 11.20 ± 2.97-67.14 ± 13.58 nM for hCA II, and 257.60 ± 27.84-442.60 ± 52.13 nM for AChE. Also, compounds SG1 and SO1 also showed ABTS radical scavenging activity at the rate of 70% and 78%, respectively. These results will contribute to the literature for the rational design and synthesis of new potent and selective inhibitors targeting hCAs and AChE with multifunctional effects such as radical scavenging as well as inhibition. This study focused on the synthesis and inhibitory effects of bis-ureido-substituted sulfaguanidine (SG1-4) and sulfisoxazole (SO1-4) derivatives against human hCA I and II isoforms and AChE. In order to test synthesized derivatives' free radical scavenging potentials were the DPPH and ABTS assays. In silico studies elucidated possible binding mechanisms of inhibitors to the active site.

Novel drug-like fluorenyl derivatives as selective butyrylcholinesterase and β-amyloid inhibitors for the treatment of Alzheimer's disease

Butyrylcholinesterase (BuChE) and amyloid β (Aβ) aggregation remain important biological target and mechanism in the search for effective treatment of Alzheimer's disease. Simultaneous inhibition thereof by the application of multifunctional agents may lead to improvement in terms of symptoms and causes of the disease. Here, we present the rational design, synthesis, biological evaluation and molecular modelling studies of novel series of fluorene-based BuChE and Aβ inhibitors with drug-like characteristics and advantageous Central Nervous System Multiparameter Optimization scores. Among 17 synthesized and tested compounds, we identified 22 as the most potent eqBuChE inhibitor with IC₅₀ of 38 nM and 37.4% of Aβ aggregation inhibition at 10 μM. Based on molecular modelling studies, including molecular dynamics, we determined the binding mode of the compounds within BuChE and explained the differences in the activity of the two enantiomers of compound 22. A novel series of fluorenyl compounds meeting the drug-likeness criteria seems to be a promising starting point for further development as anti-Alzheimer agents.

Two new dilactonized glycerol glycosides of the dual anticholinesterase active extract from Ocotea daphnifolia using bioguided fractionation and molecular docking studies

The dual inhibition of acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) is considered as an important strategy for the treatment of Alzheimer's disease. In this study, we applied the bioguided fractionations of Ocotea daphinifolia ethyl acetate active extract to furnish a fraction with high inhibitory activity for AChE and BuChE (82% and 92%, respectively). High-performance liquid chromatography semipreparative purification of this fraction provided two new natural products: 1-β-D-galactopyranosyl-glycerol-2,3-heptanedionate, (1) whose complete chemical structural elucidation was made with spectrometric analysis (MS, 1D, and 2D NMR) and its minor derivative 1-β-D-gulopyranosyl-glycerol-2,3-heptanedionate; (2) which could be characterized by 2D ¹ H-¹³ C heteronuclear single-quantum correlation spectra analysis. Investigation of the intermolecular interactions with cholinesterases was carried out by molecular docking studies, and results suggested that both compounds are capable to interact with the catalytic site of both enzymes. Compounds 1 and 2 interact with residues of catalytic domains and the peripheral anionic binding site of AChE and BuChE. The results are comparable to those achieved with rivastigmine and galantamine. Thus, this study provides evidence for consideration of the glycosylglycerol from O. daphnifolia as new valuable dual cholinesterases inhibitor.

Novel thienocycloalkylpyridazinones as useful scaffolds for acetylcholinesterase inhibition and serotonin 5-HT6 receptor interaction

A library of eighteen thienocycloalkylpyridazinones was synthesized for human acetylcholinesterase (hAChE) and butyrylcholinesterase (hBChE) inhibition and serotonin 5-HT₆ receptor subtype interaction by following a multitarget-directed ligand approach (MTDL), as a suitable strategy for treatment of Alzheimer's disease (AD). The novel compounds featured a tricyclic scaffold, namely thieno[3,2-h]cinnolinone, thienocyclopentapyridazinone and thienocycloheptapyridazinone, connected through alkyl chains of variable length to proper amine moieties, most often represented by N-benzylpiperazine or 1-(phenylsulfonyl)-4-(piperazin-1-ylmethyl)-1H-indole as structural elements addressing AChE and 5-HT₆ interaction, respectively. Our study highlighted the versatility of thienocycloalkylpyridazinones as useful architectures for AChE interaction, with several N-benzylpiperazine-based analogues emerging as potent and selective hAChE inhibitors with IC₅₀ in the 0.17-1.23 μM range, exhibiting low to poor activity for hBChE (IC₅₀ = 4.13-9.70 μM). The introduction of 5-HT₆ structural moiety phenylsulfonylindole in place of N-benzylpiperazine, in tandem with a pentamethylene linker, gave potent 5-HT₆ thieno[3,2-h]cinnolinone and thienocyclopentapyridazinone-based ligands both displaying hAChE inhibition in the low micromolar range and unappreciable activity towards hBChE. While docking studies provided a rational structural explanation for AChE/BChE enzyme and 5-HT₆ receptor interaction, in silico prediction of ADME properties of tested compounds suggested further optimization for development of such compounds in the field of MTDL for AD.

Discovery of new, highly potent and selective inhibitors of BuChE - design, synthesis, in vitro and in vivo evaluation and crystallography studies

The symptomatic and disease-modifying effects of butyrylcholinesterase (BuChE) inhibitors provide an encouraging premise for researching effective treatments for Alzheimer's disease. Here, we examined a series of compounds with a new chemical scaffold based on 3-(cyclohexylmethyl)amino-2-hydroxypropyl, and we identified a highly selective hBuChE inhibitor (29). Based on extensive in vitro and in vivo evaluations of the compound and its enantiomers, (R)-29 was identified as a promising candidate for further development. Compound (R)-29 is a potent hBuChE inhibitor (IC₅₀ = 40 nM) with selectivity over AChE and relevant off-targets, including H₁, M₁, α_1A and β₁ receptors. The compound displays high metabolic stability on human liver microsomes (90% of the parent compound after 2 h of incubation), and its safety was confirmed through examining the cytotoxicity on the HepG2 cell line (LC₅₀ = 2.85 μM) and hERG inhibition (less than 50% at 10 μM). While (rac)-29 lacked an effect in vivo and showed limited penetration to the CNS in pharmacokinetics studies, compound (R)-29 exhibited a procognitive effect at 15 mg/kg in the passive avoidance task in scopolamine-treated mice.

Piperidine Derivatives: Recent Advances in Synthesis and Pharmacological Applications

Piperidines are among the most important synthetic fragments for designing drugs and play a significant role in the pharmaceutical industry. Their derivatives are present in more than twenty classes of pharmaceuticals, as well as alkaloids. The current review summarizes recent scientific literature on intra- and intermolecular reactions leading to the formation of various piperidine derivatives: substituted piperidines, spiropiperidines, condensed piperidines, and piperidinones. Moreover, the pharmaceutical applications of synthetic and natural piperidines were covered, as well as the latest scientific advances in the discovery and biological evaluation of potential drugs containing piperidine moiety. This review is designed to help both novice researchers taking their first steps in this field and experienced scientists looking for suitable substrates for the synthesis of biologically active piperidines.

Sulfonamides with Heterocyclic Periphery as Antiviral Agents

Sulfonamides are the basic motifs for a whole generation of drugs from a large group of antibiotics. Currently, research in the field of the new sulfonamide synthesis has received a "second wind", due to the increase in the synthetic capabilities of organic chemistry and the study of their medical and biological properties of a wide spectrum of biological activity. New reagents and new reactions make it possible to significantly increase the number of compounds with a sulfonamide fragment in combination with other important pharmacophore groups, such as, for example, a wide class of N-containing heterocycles. The result of these synthetic possibilities is the extension of the activity spectrum-along with antibacterial activity, many of them exhibit other types of biological activity. Antiviral activity is also observed in a wide range of sulfonamide derivatives. This review provides examples of the synthesis of sulfonamide compounds with antiviral properties that can be used to develop drugs against coxsackievirus B, enteroviruses, encephalomyocarditis viruses, adenoviruses, human parainfluenza viruses, Ebola virus, Marburg virus, SARS-CoV-2, HIV and others. Since over the past three years, viral infections have become a special problem for public health throughout the world, the development of new broad-spectrum antiviral drugs is an extremely important task for synthetic organic and medicinal chemistry. Sulfonamides can be both sources of nitrogen for building a nitrogen-containing heterocyclic core and the side chain substituents of a biologically active substance. The formation of the sulfonamide group is often achieved by the reaction of the N-nucleophilic center in the substrate molecule with the corresponding sulfonylchloride. Another approach involves the use of sulfonamides as the reagents for building a nitrogen-containing framework.

Aaptamine - a dual acetyl - and butyrylcholinesterase inhibitor as potential anti-Alzheimer's disease agent

CONTEXT

Alzheimer's disease (AD) is a neurodegenerative disorder that affects millions of people worldwide. Acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) are promising therapeutic targets for AD.

OBJECTIVE

To evaluate the inhibitory effects of aaptamine on two cholinesterases and investigate the in vivo therapeutic effect on AD in a zebrafish model.

MATERIALS AND METHODS

Aaptamine was isolated from the sponge Aaptos suberitoides Brøndsted (Suberitidae). Enzyme inhibition, kinetic analysis, surface plasmon resonance (SPR) and molecular docking assays were used to determine its inhibitory effect on AChE and BuChE in vitro. Zebrafish were divided into six groups: control, model, 8 μM donepezil, 5 , 10  and 20 μM aaptamine. After three days of drug treatment, the behaviour assay was performed.

RESULTS

The IC₅₀ values of aaptamine towards AChE and BuChE were 16.0 and 4.6 μM. And aaptamine directly inhibited the two cholinesterases in the mixed inhibition type, with K_i values of 6.96 ± 0.04 and 6.35 ± 0.02 μM, with K_d values of 87.6 and 10.7 μM. Besides, aaptamine interacts with the crucial anionic sites of AChE and BuChE. In vivo studies indicated that the dyskinesia recovery rates of 5 , 10  and 20 μM aaptamine group were 34.8, 58.8 and 60.0%, respectively, and that of donepezil was 63.7%.

DISCUSSION AND CONCLUSIONS

Aaptamine showed great potential to exert its anti-AD effects by directly inhibiting the activities of AChE and BuChE. Therefore, this study identified a novel medicinal application of aaptamine and provided a new structural scaffold for the development of anti-AD drugs.

The Chemotype of Chromanones as a Privileged Scaffold for Multineurotarget Anti-Alzheimer Agents

The multifactorial nature of Alzheimer's disease necessitates the development of agents able to interfere with different relevant targets. A series of 22 tailored chromanones was conceptualized, synthesized, and subjected to biological evaluation. We identified one representative bearing a linker-connected azepane moiety (compound 19) with balanced pharmacological properties. Compound 19 exhibited inhibitory activities against human acetyl-, butyrylcholinesterase and monoamine oxidase-B, as well as high affinity to both the σ1 and σ2 receptors. Our study provides a framework for the development of further chromanone-based multineurotarget agents.

Synthesis, In Vitro Anti-Microbial Analysis and Molecular Docking Study of Aliphatic Hydrazide-Based Benzene Sulphonamide Derivatives as Potent Inhibitors of α-Glucosidase and Urease

A unique series of sulphonamide derivatives was attempted to be synthesized in this study using a new and effective method. All of the synthesized compounds were verified using several spectroscopic methods, including FTIR, ¹H-NMR, ¹³C-NMR, and HREI-MS, and their binding interactions were studied using molecular docking. The enzymes urease and α-glucosidase were evaluated against each derivative (1–15). When compared to their respective standard drug such as acarbose and thiourea, almost all compounds were shown to have excellent activity. Among the screened series, analogs 5 (IC₅₀ = 3.20 ± 0.40 and 2.10 ± 0.10 µM) and 6 (IC₅₀ = 2.50 ± 0.40 and 5.30 ± 0.20 µM), emerged as potent molecules when compared to the standard drugs acarbose (IC₅₀ = 8.24 ± 0.08 µM) and urease (IC₅₀ = 7.80 ± 0.30). Moreover, an anti-microbial study also demonstrated that analogs 5 and 6 were found with minimum inhibitory concentrations (MICs) in the presence of standard drugs streptomycin and terinafine.

Evaluation of the Key Structural Features of Various Butyrylcholinesterase Inhibitors Using Simple Molecular Descriptors

In this study, we developed several QSAR models based on simple descriptors (such as topological and constitutional) to estimate butyrylcholinesterase (BChE) inhibition potency, pK_i (or pIC₅₀), of a set of 297 (289 after exclusion of outliers) structurally different compounds. The models were similar to the best model that we obtained previously for acetylcholinesterase AChE and were based on the valence molecular connectivity indices of second and third order (²χ^v and ³χ^v), the number of aliphatic hydroxyl groups (nOH), AlogP Ghose-Crippen octanol-water partition coeff. (logP), and O-060-atom-centred fragments (Al-O-Ar, Ar-O-Ar, R..O..R and R-O-C=X). The best models with two and three descriptors yielded r = 0.787 and S.E. = 0.89, and r = 0.827 and S.E. = 0.81, respectively. We also correlated nine scoring functions, calculated for 20 ligands whose complexes with BChE we found in the Protein Data Bank as crystal structures to pK_i (or pIC₅₀). The best correlations yielded PLP1 and PLP2 (Piecewise Linear Pairwise potential functions) with r = 0.619 and 0.689, respectively. Correlation with certain simple topological and constitutional descriptors yielded better results, e.g., ³χ^v (r = 0.730), on the same set of compounds (N = 20).

Isosteroidal alkaloids of Fritillaria taipaiensis and their implication to Alzheimer's disease: Isolation, structural elucidation and biological activity

Four undescribed and five known isosteroidal alkaloids were isolated from the bulbs of Fritillaria taipaiensis and their structures were elucidated on the basis of HR-ESI-MS, 1D and 2D NMR spectroscopic data analyses. The undescribed compounds were designated taipainines A-D. Of these, taipainine D presented a unique structure having the D/E trans (H-13α/H-17β) and E/F cis (β-axial lone pair of the N atom/H-22β) ring junctions. Possible biosynthetic pathway to taipainine D is proposed. Four compounds showed significant BChE inhibitory activities similar or better than the positive control galantamine. In addition, the preliminary structure-activity relationships (SARs) of these isosteroidal alkaloids were also investigated.

Evaluation of chromane derivatives: Promising privileged scaffolds for lead discovery within Alzheimer's disease

The chromane ring system is widely distributed in nature and has proven to be a highly potent pharmacophore in medicinal chemistry, which includes the area of Alzheimer's and Parkinson's diseases. We report on the development of a gem-dimethylchroman-4-ol family that was shown to give good inhibition of equine serum butyrylcholinesterase (eqBuChE) (in the range 2.9 - 7.3 μM) and in the same range of currently used drugs. We also synthesized a small library of gem-dimethylchroman-4-amine compounds, via a simple reductive amination of the corresponding chromanone precursor, that were also selective for eqBuChE presenting inhibitions in the range 7.6 - 67 μM. Kinetic studies revealed that they were mixed inhibitors. Insights into their mechanism of action were obtained through molecular docking and STD-NMR experiments, and the most active examples showed excellent drug-likeness and pharmacological properties predicted using Swiss-ADME. We also prepared a set of propargyl gem-dimethylchromanamines, for monoamine oxidase (MAO) inhibition but they were only moderately active (the best being 28% inhibition at 1 µM on MAO-B). Overall, our compounds were found to be best suited as inhibitors for BuChE.

Insight into Thermodynamic and Kinetic Profiles in Small-Molecule Optimization

Structure-activity relationships (SARs) and structure-property relationships (SPRs) have been considered the most important factors during the drug optimization process. For medicinal chemists, improvements in the potencies and druglike properties of small molecules are regarded as their major goals. Among them, the binding affinity and selectivity of small molecules on their targets are the most important indicators. In recent years, there has been growing interest in using thermodynamic and kinetic profiles to analyze ligand-receptor interactions, which could provide not only binding affinities but also detailed binding parameters for small-molecule optimization. In this perspective, we are trying to provide an insight into thermodynamic and kinetic profiles in small-molecule optimization. Through a highlight of strategies on the small-molecule optimization with specific cases, we aim to put forward the importance of structure-thermodynamic relationships (STRs) and structure-kinetic relationships (SKRs), which could provide more guidance to find safe and effective small-molecule drugs.

Novel donepezil-chalcone-rivastigmine hybrids as potential multifunctional anti-Alzheimer's agents: Design, synthesis, in vitro biological evaluation, in vivo and in silico studies

Alzheimer's disease (AD) is a chronic, progressive brain neurodegenerative disorder. Up to now, there is no effective drug to halt or reverse the progress of AD. Given the complex pathogenesis of AD, the multi-target-directed ligands (MTDLs) strategy is considered as the promising therapy. Herein, a series of novel donepezil-chalone-rivastigmine hybrids was rationally designed and synthesized by fusing donepezil, chalone and rivastigmine. The in vitro bioactivity results displayed that compound 10c was a reversible huAChE (IC₅₀ = 0.87 μM) and huBuChE (IC₅₀ = 3.3 μM) inhibitor. It also presented significant anti-inflammation effects by suppressing the level of IL-6 and TNF-α production, and significantly inhibited self-mediated Aβ_1-42 aggregation (60.6%) and huAChE-mediated induced Aβ_1-40 aggregation (46.2%). In addition, 10c showed significant neuroprotective effect on Aβ_1-42-induced PC12 cell injury and activated UPS pathway in HT22 cells to degrade tau and amyloid precursor protein (APP). Furthermore, compound 10c presented good stabilty in artificial gastrointestinal fluids and liver microsomes in vitro. The pharmacokinetic study showed that compound 10c was rapidly absorbed in rats and distributed in rat brain after intragastric administration. The PET-CT imaging demonstrated that [¹¹C]10c could quickly enter the brain and washed out gradually in vivo. Further, compound 10c at a dose of 5 mg/kg improved scopolamine-induced memory impairment, deserving further investigations.

Discovery of carbamate-based N-salicyloyl tryptamine derivatives as novel pleiotropic agents for the treatment of Alzheimer's disease

In this work, based on the potential anti-AD molecule previously studied by our group, we continue to introduce different substituents at different positions to improve both drug-like properties and on target activities. 33 N-salicyloyl tryptamine-carbamate hybrids were designed, synthesized and evaluated as cholinesterase inhibitors. H327 was the most potent BChE inhibitor (eqBChE IC₅₀ = 0.057 ± 0.005 μM), and showed threefold improved inhibitory potency than the positive drug rivastigmine (eqBChE IC₅₀ = 0.19 ± 0.001 μM). In addition, H327 as a pseudo-irreversible BChE inhibitor was endowed with neuroprotective, antioxidative and anti-neuroinflammatory properties. Cytotoxicity and acute toxicity tests confirmed the safety of compound H327. The pharmacokinetics study showed that compound H327 had a longer T_1/2 time and higher bioavailability than the lead compound 1 g. Compound H327 was able to cross the blood-brain barrier (BBB) in vivo. Moreover, the behavioral tests showed that compound H327 could significantly improve scopolamine-induced cognitive impairment in vivo. Overall, these results demonstrated that compound H327 is a promising multi-target agent for the treatment of AD.

Phytochemical Characterization and Pharmacological Properties of Lichen Extracts from Cetrarioid Clade by Multivariate Analysis and Molecular Docking

Introduction

Lichens, due to the presence of own secondary metabolites such as depsidones and depsides, became a promising source of health-promoting organisms with pharmacological activities. However, lichens and their active compounds have been much less studied. Therefore, the present study aims to evaluate for the first time the antioxidant capacity and enzyme inhibitory activities of 14 lichen extracts belonging to cetrarioid clade in order to identify new natural products with potential pharmacological activity.

Materials and Methods

In this study, an integrated strategy was applied combining multivariate statistical analysis (principal component analysis and hierarchical cluster analysis), phytochemical identification, activity evaluation (in vitro battery of antioxidant assays FRAP, DPPH, and ORAC), and enzyme inhibitory activity against acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) and molecular profiling with in silico docking studies of the most promising secondary metabolites. Results. Among fourteen lichen samples, Dactylina arctica stands out for its higher antioxidant capacities, followed by Nephromopsis stracheyi, Tuckermannopsis americana, Vulpicida pinastri, and Asahinea scholanderi. Moreover, Asahinea scholanderi and Cetraria cucullata extracts were the best inhibitors of AChE and BuChE. The major secondary metabolites identified by HPLC were alectoronic acid and α-collatolic acid for Asahinea scholanderi and usnic acid and protolichesterinic acid for Cetraria cucullata. Molecular docking studies revealed that alectoronic acid exhibited the strongest binding affinity with both AChE and BuChE with and without water molecules.

Conclusions

Our results concluded that these species could be effective in the treatment of neurodegenerative diseases, being mandatory further investigation in cell culture and in vivo models.

First crystal structures of 1-deoxy-D-xylulose 5-phosphate synthase (DXPS) from Mycobacterium tuberculosis indicate a distinct mechanism of intermediate stabilization

The development of drug resistance by Mycobacterium tuberculosis and other pathogenic bacteria emphasizes the need for new antibiotics. Unlike animals, most bacteria synthesize isoprenoid precursors through the MEP pathway. 1-Deoxy-d-xylulose 5-phosphate synthase (DXPS) catalyzes the first reaction of the MEP pathway and is an attractive target for the development of new antibiotics. We report here the successful use of a loop truncation to crystallize and solve the first DXPS structures of a pathogen, namely M. tuberculosis (MtDXPS). The main difference found to other DXPS structures is in the active site where a highly coordinated water was found, showing a new mechanism for the enamine-intermediate stabilization. Unlike other DXPS structures, a “fork-like” motif could be identified in the enamine structure, using a different residue for the interaction with the cofactor, potentially leading to a decrease in the stability of the intermediate. In addition, electron density suggesting a phosphate group could be found close to the active site, provides new evidence for the D-GAP binding site. These results provide the opportunity to improve or develop new inhibitors specific for MtDXPS through structure-based drug design.

Development of naringenin-O-alkylamine derivatives as multifunctional agents for the treatment of Alzheimer's disease

In this study, a series of naringenin-O-alkylamine derivatives were designed and obtained by introducing an alkylamine fragment into the naringenin skeleton. The in vitro biological activity results revealed that compounds 5f and 7k showed good antioxidant activity with ORAC values of 2.3eq and 1.2eq, respectively. Compounds 5f and 7k were reversible and excellent huAChE inhibitors with IC₅₀ values of 0.91 μM and 0.57 μM, respectively. Moreover, compounds 5f and 7k could inhibit self-induced Aβ_1–42 aggregation with 62.1% and 43.8% inhibition rate, respectively, and significantly inhibited huAChE-Aβ_1–40 aggregation with 51.7% and 43.4% inhibition rate, respectively. In addition, compounds 5f and 7k were selective metal chelators and remarkably inhibited Cu²⁺-induced Aβ_1–42 aggregation with 73.5% and 68.7% inhibition rates, respectively. Furthermore, compounds 5f and 7k could cross the blood-brain barrier in vitro and displayed good neuroprotective effects and anti-inflammatory properties. Further investigation showed that compound 5f did not show obvious hepatotoxicity and displayed a good hepatoprotective effect by its antioxidant activity. The in vivo study displayed that compound 5f significantly improved scopolamine-induced mice memory impairment. Therefore, compound 5f was a potential multifunctional candidate for the treatment of AD.

Photoswitchable Pseudoirreversible Butyrylcholinesterase Inhibitors Allow Optical Control of Inhibition in Vitro and Enable Restoration of Cognition in an Alzheimer's Disease Mouse Model upon Irradiation

To develop tools to investigate the biological functions of butyrylcholinesterase (BChE) and the mechanisms by which BChE affects Alzheimer's disease (AD), we synthesized several selective, nanomolar active, pseudoirreversible photoswitchable BChE inhibitors. The compounds were able to specifically influence different kinetic parameters of the inhibition process by light. For one compound, a 10-fold difference in the IC₅₀-values (44.6 nM cis, 424 nM trans) in vitro was translated to an "all or nothing" response with complete recovery in a murine cognition-deficit AD model at dosages as low as 0.3 mg/kg.

Anti-human Glioma Cancer Potentials of Neobavaisoflavone as Natural Antioxidant Compound and Its Inhibition Profiles for Acetylcholinesterase and Butyrylcholinesterase Enzymes with Molecular Modeling and Spin Density Distributions Studies

In this study, the carcinogenic potential of Neobavaisoflavone as a natural antioxidant compound and the inhibitory profiles of acetylcholinesterase and butyrylcholinesterase were investigated by molecular modeling and spin density distribution studies. To evaluate the antioxidant properties of neobavaisoflavone, DPPH test was performed in the presence of butyl hydroxytoluene as a control. Neobavaisoflavone cell viability was low compared to normal human glioma cancer cell lines, namely LN-229, U-87 and A-172 cell lines, without any effect of cytotoxicity on normal cell line. Neobavaisoflavone inhibited half of DPPH at 125 μg/mL. The best effects of Neobavaisoflavone antihypertensive glioma against the above cell lines were in the LN-229 cell line. In addition, the significant anti-cancer potential of human glioma Neobavaisoflavone against the popular human glioma cancer cell lines is related in this study. IC₅₀ values were calculated by Neobavaisoflavone diagrams, 63.87 nM for AChE and 112.98 nM for BuChE, % Activity- [Inhibitor]. According to the above results, Neobavaisoflavone can be used to treat a variety of human glioma cancers in humans. In addition, molecular modeling calculations were performed to compare the biochemical activities of the Neobavaisoflavone molecule with enzymes. After molecular insertion calculations, ADME/T analysis was performed to investigate the properties of the neobavaisoflavone molecule, which will be used as a drug in the future. Then, different parameters for the antioxidant activity of the neobavaisoflavone molecule were calculated.

Repurposing of 8-Hydroxyquinoline-based Butyrylcholinesterase and Cathepsin B Ligands as Potent Non-peptidic Deoxyribonuclease I Inhibitors

A library of 31 butyrylcholinesterase (BChE) and cathepsin B (CatB) inhibitors, was screened in vitro for inhibition of deoxyribonuclease I (DNase I). Compounds 22, 8 and 7 are among the most potent synthetic non-peptide DNase I inhibitors reported up to date. Three 8-hydroxyquinoline analogues inhibited both DNase I and BChE with IC50 values below 35 µM and 50 nM, respectively, while 2 nitroxoline derivatives inhibited DNase I and Cat B endopeptidase activity with IC50 values below 60 µM and 20 µM, respectively. Selected derivatives were screened for various co-target binding affinities at dopamine D2 and D3, histamine H3 and H4 receptors and inhibition of 5-lipoxygenase. Compound 8 bound to the H3 receptor and is highlighted as the most promising multifunctional ligand with a favorable pharmacokinetic profile and one of the most potent non-peptide DNase I inhibitors. The present study demonstrates that 8-hydroxyquinoline is a structural fragment critical for DNase I inhibition in the presented series of compounds.

Therapeutic potential of quinazoline derivatives for Alzheimer's disease: A comprehensive review

Quinazolines are considered as a promising class of bioactive heterocyclic compounds with broad properties. Particularly, the quinazoline scaffold has an impressive role in the design and synthesis of new CNS-active drugs. The drug-like properties and pharmacological characteristics of quinazoline could lead to different drugs with various targets. Among CNS disorders, Alzheimer's disease (AD) is a progressive neurodegenerative disorder with memory loss, cognitive decline and language dysfunction. AD is a complex and multifactorial disease therefore, the need for finding multi-target drugs against this devastative disease is urgent. A literature survey revealed that quinazoline derivatives have diverse therapeutic potential for AD as modulators/inhibitors of β-amyloid, tau protein, cholinesterases, monoamine oxidases, and phosphodiesterases as well as other protective effects. Thus, we describe here the most relevant and recent studies about anti-AD agents with quinazoline structure which can further aid the development and discovery of new anti-AD agents.

New Pyrimidine and Pyridine Derivatives as Multitarget Cholinesterase Inhibitors: Design, Synthesis, and In Vitro and In Cellulo Evaluation

A new series of pyrimidine and pyridine diamines was designed as dual binding site inhibitors of cholinesterases (ChEs), characterized by two small aromatic moieties separated by a diaminoalkyl flexible linker. Many compounds are mixed or uncompetitive acetylcholinesterase (AChE) and/or butyrylcholinesterase (BChE) nanomolar inhibitors, with compound 9 being the most active on Electrophorus electricus AChE (EeAChE) (K_i = 0.312 μM) and compound 22 on equine BChE (eqBChE) (K_i = 0.099 μM). Molecular docking and molecular dynamic studies confirmed the interaction mode of our compounds with the enzymatic active site. UV–vis spectroscopic studies showed that these compounds can form complexes with Cu²⁺ and Fe³⁺ and that compounds 18, 20, and 30 have antioxidant properties. Interestingly, some compounds were also able to reduce Aβ₄₂ and tau aggregation, with compound 28 being the most potent (22.3 and 17.0% inhibition at 100 μM on Aβ₄₂ and tau, respectively). Moreover, the most active compounds showed low cytotoxicity on a human brain cell line and they were predicted as BBB-permeable.

Novel cannabidiol-carbamate hybrids as selective BuChE inhibitors: Docking-based fragment reassembly for the development of potential therapeutic agents against Alzheimer's disease

Cannabidiol (CBD) and rivastigmine have been launched as drugs for treating dementia and cholinesterases (ChEs) are ideal drug targets. This study focused on developing novel ChE inhibitors as drug leads against dementia through molecular modeling and fragment reassembly approaches. A potent carbamate fragment binding to active site gorge of BuChE was found via a docking-based structural splicing approach, thus, 17 novel compounds were designed by structural reassembly. Compound C16 was identified as a highly selective potent BuChE inhibitor (IC₅₀ = 5.3 nM, SI > 4000), superior to CBD (IC₅₀ = 0.67 μM). C16 possessed BBB penetrating ability, benign safety, neuroprotection, antioxidant and pseudo-irreversible BuChE inhibition (K_d = 13 nM, k₂ = 0.26 min^-1), showing good drug-like properties. In vivo studies confirmed that C16 significantly ameliorated the scopolamine-induced cognition impairment, almost entirely recovered the Aβ_1-42 (icv)-impaired cognitive function to the normal level, showed better behavioral performance than donepezil and good anti-amyloidogenic effect. Hence, the potential BuChE inhibitor C16 can be developed as a promising disease-modifying treatment of AD.

Discovery of sustainable drugs for Alzheimer's disease: cardanol-derived cholinesterase inhibitors with antioxidant and anti-amyloid properties

As part of our efforts to develop sustainable drugs for Alzheimer's disease (AD), we have been focusing on the inexpensive and largely available cashew nut shell liquid (CNSL) as a starting material for the identification of new acetylcholinesterase (AChE) inhibitors. Herein, we decided to investigate whether cardanol, a phenolic CNSL component, could serve as a scaffold for improved compounds with concomitant anti-amyloid and antioxidant activities. Ten new derivatives, carrying the intact phenolic function and an aminomethyl functionality, were synthesized and first tested for their inhibitory potencies towards AChE and butyrylcholinesterase (BChE). 5 and 11 were found to inhibit human BChE at a single-digit micromolar concentration. Transmission electron microscopy revealed the potential of five derivatives to modulate Aβ aggregation, including 5 and 11. In HORAC assays, 5 and 11 performed similarly to standard antioxidant ferulic acid as hydroxyl scavenging agents. Furthermore, in in vitro studies in neuronal cell cultures, 5 and 11 were found to effectively inhibit reactive oxygen species production at a 10 μM concentration. They also showed a favorable initial ADME/Tox profile. Overall, these results suggest that CNSL is a promising raw material for the development of potential disease-modifying treatments for AD.

Novel inhibitors with sulfamethazine backbone: synthesis and biological study of multi-target cholinesterases and α-glucosidase inhibitors

The underlying cause of many metabolic diseases is abnormal changes in enzyme activity in metabolism. Inhibition of metabolic enzymes such as cholinesterases (ChEs; acetylcholinesterase, AChE and butyrylcholinesterase, BChE) and α-glucosidase (α-GLY) is one of the accepted approaches in the treatment of Alzheimer's disease (AD) and diabetes mellitus (DM). Here we reported an investigation of a new series of novel ureido-substituted derivatives with sulfamethazine backbone (2a-f) for the inhibition of AChE, BChE, and α-GLY. All the derivatives demonstrated activity in nanomolar levels as AChE, BChE, and α-GLY inhibitors with K_I values in the range of 56.07-204.95 nM, 38.05-147.04 nM, and 12.80-79.22 nM, respectively. Among the many strong N-(4,6-dimethylpyrimidin-2-yl)-4-(3-substitutedphenylureido) benzenesulfonamide derivatives (2a-f) detected against ChEs, compound 2c, the 4-fluorophenylureido derivative, demonstrated the most potent inhibition profile towards AChE and BChE. A comprehensive ligand/receptor interaction prediction was performed in silico for the three metabolic enzymes providing molecular docking investigation using Glide XP, MM-GBSA, and ADME-Tox modules. The present research reinforces the rationale behind utilizing inhibitors with sulfamethazine backbone as innovative anticholinergic and antidiabetic agents with a new mechanism of action, submitting propositions for the rational design and synthesis of novel strong inhibitors targeting ChEs and α-GLY.Communicated by Ramaswamy H. Sarma.