RESUMEN
Heterocyclic thiones have recently been identified as reversible covalent warheads, consistent with their mild electrophilic nature. Little is known so far about their mechanism of action in labelling nucleophilic sidechains, especially cysteines. The vast number of tractable cysteines promotes a wide range of target proteins to examine; however, our focus was put on functional cysteines. We chose the main protease of SARS-CoV-2 harboring Cys145 at the active site that is a structurally characterized and clinically validated target of covalent inhibitors. We screened an in-house, cysteine-targeting covalent inhibitor library which resulted in several covalent fragment hits with benzoxazole, benzothiazole and benzimidazole cores. Thione derivatives and Michael acceptors were selected for further investigations with the objective of exploring the mechanism of inhibition of the thiones and using the thoroughly characterized Michael acceptors for benchmarking our studies. Classical and hybrid quantum mechanical/molecular mechanical (QM/MM) molecular dynamics simulations were carried out that revealed a new mechanism of covalent cysteine labelling by thione derivatives, which was supported by QM and free energy calculations and by a wide range of experimental results. Our study shows that the molecular recognition step plays a crucial role in the overall binding of both sets of molecules.
Asunto(s)
Cisteína , Tionas , Cisteína/química , Simulación de Dinámica Molecular , Dominio Catalítico , Simulación del Acoplamiento MolecularRESUMEN
Penicillin-binding proteins (PBPs) contribute to bacterial cell wall biosynthesis and are targets of antibacterial agents. Here, we investigated PBP1b inhibition by boronic acid derivatives. Chemical starting points were identified by structure-based virtual screening and aliphatic boronic acids were selected for further investigations. Structure-activity relationship studies focusing on the branching of the boron-connecting carbon and quantum mechanical/molecular mechanical simulations showed that reaction barrier free energies are compatible with fast reversible covalent binding and small or missing reaction free energies limit the inhibitory activity of the investigated boronic acid derivatives. Therefore, covalent labelling of the lysine residue of the catalytic dyad was also investigated. Compounds with a carbonyl warhead and an appropriately positioned boronic acid moiety were shown to inhibit and covalently label PBP1b. Reversible covalent labelling of the catalytic lysine by imine formation and the stabilisation of the imine by dative N-B bond is a new strategy for PBP1b inhibition.
Asunto(s)
Lisina , Serina , Proteínas de Unión a las Penicilinas/química , Proteínas de Unión a las Penicilinas/metabolismo , Ácidos Borónicos/farmacología , Antibacterianos/farmacología , IminasRESUMEN
The lack of efficient methods to control the major diseases of crops most important to agriculture leads to huge economic losses and seriously threatens global food security. Many of the most important microbial plant pathogens, including bacteria, fungi, and oomycetes, secrete necrosis- and ethylene-inducing peptide 1 (Nep1)-like proteins (NLPs), which critically contribute to the virulence and spread of the disease. NLPs are cytotoxic to eudicot plants, as they disturb the plant plasma membrane by binding to specific plant membrane sphingolipid receptors. Their pivotal role in plant infection and broad taxonomic distribution makes NLPs a promising target for the development of novel phytopharmaceutical compounds. To identify compounds that bind to NLPs from the oomycetes Pythium aphanidermatum and Phytophthora parasitica, a library of 587 small molecules, most of which are commercially unavailable, was screened by surface plasmon resonance. Importantly, compounds that exhibited the highest affinity to NLPs were also found to inhibit NLP-mediated necrosis in tobacco leaves and Phytophthora infestans growth on potato leaves. Saturation transfer difference-nuclear magnetic resonance and molecular modelling of the most promising compound, anthranilic acid derivative, confirmed stable binding to the NLP protein, which resulted in decreased necrotic activity and reduced ion leakage from tobacco leaves. We, therefore, confirmed that NLPs are an appealing target for the development of novel phytopharmaceutical agents and strategies, which aim to directly interfere with the function of these major microbial virulence factors. The compounds identified in this study represent lead structures for further optimization and antimicrobial product development.
Asunto(s)
Phytophthora/patogenicidad , Enfermedades de las Plantas/prevención & control , Pythium/patogenicidad , Solanum tuberosum/genética , Simulación de Dinámica Molecular , Necrosis , Phytophthora/genética , Enfermedades de las Plantas/parasitología , Hojas de la Planta/genética , Hojas de la Planta/parasitología , Pythium/genética , Solanum tuberosum/parasitología , Resonancia por Plasmón de Superficie , Nicotiana/genética , Nicotiana/parasitologíaRESUMEN
MurC, D, E, and F are ATP-dependent ligases involved in the stepwise assembly of the tetrapeptide stem of forming peptidoglycan. As highly conserved targets found exclusively in bacterial cells, they are of significant interest for antibacterial drug discovery. In this study, we employed a computer-aided molecular design approach to identify potential inhibitors of MurF. A biochemical inhibition assay was conducted, screening twenty-four flavonoids and related compounds against MurC-F, resulting in the identification of quercitrin, myricetin, and (-)-epicatechin as MurF inhibitors with IC50 values of 143 µM, 139 µM, and 92 µM, respectively. Notably, (-)-epicatechin demonstrated mixed type inhibition with ATP and uncompetitive inhibition with D-Ala-D-Ala dipeptide and UM3DAP substrates. Furthermore, in silico analysis using Sitemap and subsequent docking analysis using Glide revealed two plausible binding sites for (-)-epicatechin. The study also investigated the crucial structural features required for activity, with a particular focus on the substitution pattern and hydroxyl group positions, which were found to be important for the activity. The study highlights the significance of computational approaches in targeting essential enzymes involved in bacterial peptidoglycan synthesis.
Asunto(s)
Catequina , Ligasas , Catequina/farmacología , Peptidoglicano , Flavonoides/farmacología , Adenosina Trifosfato , Péptido Sintasas/química , Péptido Sintasas/metabolismoRESUMEN
New therapeutic targets that could improve current antitumor therapy and overcome cancer resistance are urgently needed. Promising candidates are lysosomal cysteine cathepsins, proteolytical enzymes involved in various critical steps during cancer progression. Among them, cathepsin X, which acts solely as a carboxypeptidase, has received much attention. Our results indicate that the triazole-based selective reversible inhibitor of cathepsin X named Z9 (1-(2,3-dihydrobenzo[b][1,4]dioxin-6-yl)-2-((4-isopropyl-4H-1,2,4-triazol-3-yl)thio)ethan-1-one) significantly reduces tumor progression, both in vitro in cell-based functional assays and in vivo in two independent tumor mouse models: the FVB/PyMT transgenic and MMTV-PyMT orthotopic breast cancer mouse models. One of the mechanisms by which cathepsin X contributes to cancer progression is the compensation of cathepsin-B activity loss. Our results confirm that cathepsin-B inhibition is compensated by an increase in cathepsin X activity and protein levels. Furthermore, the simultaneous inhibition of both cathepsins B and X with potent, selective, reversible inhibitors exerted a synergistic effect in impairing processes of tumor progression in in vitro cell-based assays of tumor cell migration and spheroid growth. Taken together, our data demonstrate that Z9 impairs tumor progression both in vitro and in vivo and can be used in combination with other peptidase inhibitors as an innovative approach to overcome resistance to antipeptidase therapy.
Asunto(s)
Catepsina B/antagonistas & inhibidores , Catepsinas/antagonistas & inhibidores , Inhibidores Enzimáticos/farmacología , Neoplasias Mamarias Experimentales/tratamiento farmacológico , Carga Tumoral/efectos de los fármacos , Animales , Catepsina B/metabolismo , Catepsinas/genética , Catepsinas/metabolismo , Muerte Celular/efectos de los fármacos , Línea Celular , Movimiento Celular/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Ensayos de Selección de Medicamentos Antitumorales/métodos , Inhibidores Enzimáticos/química , Humanos , Neoplasias Mamarias Experimentales/metabolismo , Neoplasias Mamarias Experimentales/patología , Ratones Transgénicos , Invasividad Neoplásica , Infiltración Neutrófila/efectos de los fármacosRESUMEN
Bacterial resistance is an increasing threat to healthcare systems, highlighting the need for discovering new antibacterial agents. An established technique, fragment-based drug discovery, was used to target a bacterial enzyme Ddl involved in the biosynthesis of peptidoglycan. We assembled general and focused fragment libraries that were screened in a biochemical inhibition assay. Screening revealed a new fragment-hit inhibitor of DdlB with a Ki value of 20.7 ± 4.5 µM. Binding to the enzyme was confirmed by an orthogonal biophysical method, surface plasmon resonance, making the hit a promising starting point for fragment development.
Asunto(s)
Antibacterianos , Peptidoglicano , Antibacterianos/farmacología , Pared Celular , Bioensayo , LigasasRESUMEN
Screening of DNA-encoded libraries is an emerging technology for discovering hits against protein targets. With the recent launch of the DELopen platform, a facile screening of 4.4 billion compounds is available to accelerate the drug discovery process. Here we report an affinity-based screening of the DELopen library for the first time. The screening was performed against two bacterial enzymes of the peptidoglycan biosynthetic pathway, N-acetylglucosamine-enolpyruvyl transferase (MurA) and d-alanine:d-alanine ligase (DdlB). Several binders were obtained and selected for off-DNA synthesis. Hits with confirmed inhibitory potency were deconstructed into smaller fragments. In this way, two new MurA inhibitors with antibacterial activity were obtained and are available for further optimization.
Asunto(s)
Transferasas Alquil y Aril , Peptidoglicano , Alanina , Vías Biosintéticas , ADN , Inhibidores Enzimáticos/farmacologíaRESUMEN
The protein data bank (PDB) is a rich source of protein ligand structures, but ligands are not explicitly used in current docking algorithms. We have developed ProBiS-Dock, a docking algorithm complementary to the ProBiS-Dock Database (J. Chem. Inf. Model. 2021, 61, 4097-4107) that treats small molecules and proteins as fully flexible entities and allows conformational changes in both after ligand binding. A new scoring function is described that consists of a binding site-specific scoring function (ProBiS-Score) and a general statistical scoring function. ProBiS-Dock enables rapid docking of small molecules to proteins and has been successfully validated in silico against standard benchmarks. It enables rapid search for new active ligands by leveraging existing knowledge in the PDB. The potential of the software for drug development has been confirmed in vitro by the discovery of new inhibitors of human indoleamine 2,3-dioxygenase 1, an enzyme that is an attractive target for cancer therapy and catalyzes the first rate-determining step of l-tryptophan metabolism via the kynurenine pathway. The software is freely available to academic users at http://insilab.org/probisdock.
Asunto(s)
Algoritmos , Proteínas , Sitios de Unión , Humanos , Ligandos , Unión Proteica , Conformación Proteica , Proteínas/química , Programas InformáticosRESUMEN
The therapeutic indications for monoamine oxidases A and B (MAO-A and MAO-B) inhibitors that have emerged from biological studies on animal and cellular models of neurological and oncological diseases have focused drug discovery projects upon identifying reversible MAO inhibitors. Screening of our in-house academic compound library identified two hit compounds that inhibit MAO-B with IC50 values in micromolar range. Two series of indole (23 analogues) and 3-(benzyloxy)benzyl)piperazine (16 analogues) MAO-B inhibitors were derived from hits, and screened for their structure-activity relationships. Both series yielded low micromolar selective inhibitors of human MAO-B, namely indole 2 (IC50 = 12.63 ± 1.21 µM) and piperazine 39 (IC50 = 19.25 ± 4.89 µM), which is comparable to selective MAO-B inhibitor isatin (IC50 = 6.10 ± 2.81 µM), yet less potent in comparison to safinamide (IC50 = 0.029 ± 0.002 µM). Selective MAO-B inhibitors 2, 14, 38 and 39 exhibited favourable permeation of the blood-brain barrier and low cytotoxicity in the human neuroblastoma cell line SH-SY5Y.
Asunto(s)
Antineoplásicos/farmacología , Indoles/farmacología , Inhibidores de la Monoaminooxidasa/farmacología , Monoaminooxidasa/metabolismo , Piperazina/farmacología , Animales , Antineoplásicos/síntesis química , Antineoplásicos/química , Proliferación Celular/efectos de los fármacos , Supervivencia Celular/efectos de los fármacos , Células Cultivadas , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Ensayos de Selección de Medicamentos Antitumorales , Humanos , Indoles/síntesis química , Indoles/química , Ratones , Modelos Moleculares , Estructura Molecular , Inhibidores de la Monoaminooxidasa/síntesis química , Inhibidores de la Monoaminooxidasa/química , Nitritos/análisis , Piperazina/síntesis química , Piperazina/química , Relación Estructura-ActividadRESUMEN
Tuberculosis (TB), caused by Mycobacterium tuberculosis (Mtb) is the number one cause of deaths due to a single infectious agent worldwide. The treatment of TB is lengthy and often complicated by the increasing drug resistance. New compounds with new mechanisms of action are therefore needed. We present the design, synthesis, and biological evaluation of pyrazine-based inhibitors of a prominent antimycobacterial drug target - mycobacterial methionine aminopeptidase 1 (MtMetAP1). The inhibitory activities of the presented compounds were evaluated against the MtMetAP1a isoform, and all derivatives were tested against a broad spectrum of myco(bacteria) and fungi. The cytotoxicity of the compounds was also investigated using Hep G2 cell lines. Overall, high inhibition of the isolated enzyme was observed for 3-substituted N-(thiazol-2-yl)pyrazine-2-carboxamides, particularly when the substituent was represented by 2-substituted benzamide. The extent of inhibition was strongly dependent on the used metal cofactor. The highest inhibition was seen in the presence of Ni2+. Several compounds also showed mediocre in vitro potency against Mtb (both Mtb H37Ra and H37Rv). Despite the structural similarities of bacterial and fungal MetAP1 to mycobacterial MtMetAP1, title compounds did not exert antibacterial nor antifungal activity. The reasons behind the higher activity of 2-substituted benzamido derivatives, as well as the correlation of enzyme inhibition with the in vitro growth inhibition activity is discussed.
Asunto(s)
Aminopeptidasas/antagonistas & inhibidores , Diseño de Fármacos , Inhibidores Enzimáticos/farmacología , Mycobacterium tuberculosis/efectos de los fármacos , Pirazinas/farmacología , Aminopeptidasas/metabolismo , Antituberculosos , Relación Dosis-Respuesta a Droga , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/química , Pruebas de Sensibilidad Microbiana , Estructura Molecular , Mycobacterium tuberculosis/enzimología , Pirazinas/síntesis química , Pirazinas/química , Relación Estructura-ActividadRESUMEN
Glioblastoma (GBM) is the most common and deadly primary brain tumor in adults. Understanding GBM pathobiology and discovering novel therapeutic targets are critical to finding efficient treatments. Upregulation of the lysosomal cysteine carboxypeptidase cathepsin X has been linked to immune dysfunction and neurodegenerative diseases, but its role in cancer and particularly in GBM progression in patients is unknown. In this study, cathepsin X expression and activity were found to be upregulated in human GBM tissues compared to low-grade gliomas and nontumor brain tissues. Cathepsin X was localized in GBM cells as well as in tumor-associated macrophages and microglia. Subsequently, potent irreversible (AMS36) and reversible (Z7) selective cathepsin X inhibitors were tested in vitro. Selective cathepsin X inhibitors decreased the viability of patient-derived GBM cells as well as macrophages and microglia that were cultured in conditioned media of GBM cells. We next examined the expression pattern of neuron-specific enzyme γ-enolase, which is the target of cathepsin X. We found that there was a correlation between high proteolytic activity of cathepsin X and C-terminal cleavage of γ-enolase and that cathepsin X and γ-enolase were colocalized in GBM tissues, preferentially in GBM-associated macrophages and microglia. Taken together, our results on patient-derived material suggest that cathepsin X is involved in GBM progression and is a potential target for therapeutic approaches against GBM.
Asunto(s)
Neoplasias Encefálicas/metabolismo , Catepsina Z/metabolismo , Glioblastoma/metabolismo , Fosfopiruvato Hidratasa/metabolismo , Microambiente Tumoral , Neoplasias Encefálicas/tratamiento farmacológico , Neoplasias Encefálicas/genética , Catepsina Z/antagonistas & inhibidores , Catepsina Z/genética , Regulación Neoplásica de la Expresión Génica , Glioblastoma/tratamiento farmacológico , Glioblastoma/genética , Humanos , Macrófagos/efectos de los fármacos , Macrófagos/metabolismo , Microglía/efectos de los fármacos , Microglía/metabolismo , Regulación hacia ArribaRESUMEN
Open innovation initiatives provide opportunities for collaboration and sharing of knowledge and experience between industry, academia, and government institutions. Through open innovation, Merck is offering a Mini Library of 80 carefully selected compounds from previous research and development projects to a broader scientific community for testing in academic drug discovery projects. These compounds are predominantly drug-like and cover a broad range of molecular targets. They could potentially interact with other enzymes, receptors, transporters, and ion channels of interest. The Mini Library was tested on seven in-house enzymes (bacterial MurA, MurC ligase, and DdlB enzyme, human MAO-A/B, human BChE, and murine AChE), and several hits were identified. A follow-up series of structural analogues provided by Merck gave a more detailed insight into the accessibility and the quality of the hit compounds. For example, sartan derivatives were moderate inhibitors of MurC, whereas bisarylureas were potent, selective, nanomolar inhibitors of hMAO-B. Importantly, 3-n-butyl-substituted indoles were identified as low nanomolar selective inhibitors of hBChE. All in all, the hit derivatives provide new starting points for the further exploration of the chemical space of high-quality enzyme inhibitors.
Asunto(s)
Inhibidores Enzimáticos , Monoaminooxidasa , Animales , Inhibidores de la Colinesterasa/química , Inhibidores Enzimáticos/farmacología , Humanos , Ratones , Monoaminooxidasa/metabolismo , Inhibidores de la Monoaminooxidasa/química , Investigación , Relación Estructura-ActividadRESUMEN
Alzheimer's disease (AD) is a complex disorder characterized by impaired neurotransmission in cholinergic and monoaminergic neurons, which, in combination with the accumulation of misfolded proteins and increased oxidative stress, leads to the typical features of the disease at the biomolecular level. Given the limited therapeutic success of approved drugs, it is imperative to explore rationally supported therapeutic approaches to combat this disease. The search for novel scaffolds that bind to different receptors and inhibit AD disease-related enzymes could lead to new therapeutic solutions. Here, we describe N-hydroxy-N-propargylamide hybrids 1-6, which were designed by combining the structures of Contilisant-a multifunctional anti-AD ligand-and ferulic acid, a natural antioxidant with various other biological activities. Among the synthesized compounds, we identified compound 4 as a micromolar inhibitor of hAChE with a potent radical-scavenging capacity comparable to resveratrol and Trolox. In addition, compound 4 chelated copper(II) ions associated with amyloid ß pathology, mitochondrial dysfunction, and oxidative stress. The promising in vitro activity combined with favorable drug-like properties and predicted blood-brain barrier permeability make compound 4 a multifunctional ligand that merits further studies at the biochemical and cellular levels.
Asunto(s)
Enfermedad de Alzheimer , Monoaminooxidasa , Humanos , Monoaminooxidasa/metabolismo , Colinesterasas/metabolismo , Péptidos beta-Amiloides/metabolismo , Inhibidores de la Monoaminooxidasa/química , Inhibidores de la Colinesterasa/química , Ligandos , Enfermedad de Alzheimer/metabolismo , Antioxidantes/química , Acetilcolinesterasa/metabolismoRESUMEN
Targeted covalent inhibition and the use of irreversible chemical probes are important strategies in chemical biology and drug discovery. To date, the availability and reactivity of cysteine residues amenable for covalent targeting have been evaluated by proteomic and computational tools. Herein, we present a toolbox of fragments containing a 3,5-bis(trifluoromethyl)phenyl core that was equipped with chemically diverse electrophilic warheads showing a range of reactivities. We characterized the library members for their reactivity, aqueous stability and specificity for nucleophilic amino acids. By screening this library against a set of enzymes amenable for covalent inhibition, we showed that this approach experimentally characterized the accessibility and reactivity of targeted cysteines. Interesting covalent fragment hits were obtained for all investigated cysteine-containing enzymes.
Asunto(s)
Transferasas Alquil y Aril/antagonistas & inhibidores , Cisteína/antagonistas & inhibidores , Descubrimiento de Drogas , Inhibidores Enzimáticos/farmacología , Proteoma/análisis , Proteoma/metabolismo , Cisteína/metabolismo , Inhibidores Enzimáticos/química , Ensayos Analíticos de Alto Rendimiento , Humanos , Proteoma/químicaRESUMEN
Antibiotic resistance represents one of the biggest public health challenges in the last few years. Mur ligases (MurC-MurF) are involved in the synthesis of UDP-N-acetylmuramyl-pentapeptide, the main building block of bacterial peptidoglycan polymer. They are essential for the survival of bacteria and therefore important antibacterial targets. We report herein the synthesis and structure-activity relationships of Mur ligases inhibitors with an azastilbene scaffold. Several compounds showed promising inhibitory potencies against multiple ligases and one compound also possessed moderate antibacterial activity. These results represent a solid ground for further development and optimization of structurally novel antimicrobial agents to combat the rising bacterial resistance.
Asunto(s)
Antibacterianos/farmacología , Proteínas Bacterianas/antagonistas & inhibidores , Compuestos de Bencilideno/farmacología , Inhibidores Enzimáticos/farmacología , Péptido Sintasas/antagonistas & inhibidores , Piridinas/farmacología , Antibacterianos/síntesis química , Antibacterianos/metabolismo , Proteínas Bacterianas/metabolismo , Compuestos de Bencilideno/síntesis química , Compuestos de Bencilideno/metabolismo , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/metabolismo , Simulación del Acoplamiento Molecular , Estructura Molecular , Péptido Sintasas/metabolismo , Unión Proteica , Piridinas/síntesis química , Piridinas/metabolismo , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/enzimología , Relación Estructura-ActividadRESUMEN
Here we present WIDOCK, a virtual screening protocol that supports the selection of diverse electrophiles as covalent inhibitors by incorporating ligand reactivity towards cysteine residues into AutoDock4. WIDOCK applies the reactive docking method (Backus et al. in Nature 534:570-574, 2016) and extends it into a virtual screening tool by introducing facile experimental or computational parametrization and a ligand focused evaluation scheme together with a retrospective and prospective validation against various therapeutically relevant targets. Parameters accounting for ligand reactivity are derived from experimental reaction kinetic data or alternatively from computed reaction barriers. The performance of this docking protocol was first evaluated by investigating compound series with diverse warhead chemotypes against KRASG12C, MurA and cathepsin B. In addition, WIDOCK was challenged on larger electrophilic libraries screened against OTUB2 and NUDT7. These retrospective analyses showed high sensitivity in retrieving experimental actives, by also leading to superior ROC curves, AUC values and better enrichments than the standard covalent docking tool available in AutoDock4 when compound collections with diverse warheads were investigated. Finally, we applied WIDOCK for the prospective identification of covalent human MAO-A inhibitors acting via a new mechanism by binding to Cys323. The inhibitory activity of several predicted compounds was experimentally confirmed and the labelling of Cys323 was proved by subsequent MS/MS measurements. These findings demonstrate the usefulness of WIDOCK as a warhead-sensitive, covalent virtual screening protocol.
Asunto(s)
Transferasas Alquil y Aril/química , Catepsina B/química , Inhibidores Enzimáticos/química , Proteínas Proto-Oncogénicas p21(ras)/química , Secuencia de Aminoácidos , Sitios de Unión , Cisteína/química , Glutatión/química , Ligandos , Simulación del Acoplamiento Molecular , Unión Proteica , Conformación Proteica , Programas Informáticos , Relación Estructura-ActividadRESUMEN
Monocyclic ß-lactams (azetidin-2-ones) exhibit a wide range of biological activities, the most important of which are antibacterial, anticancer, and cholesterol absorption inhibitory activities. The synthesis of decorated monocyclic ß-lactams is challenging because their ring is highly constrained and consequently reactive, which is also an important determinant of their biological activity. We present the optimized synthesis of orthogonally protected 3-amino-4-substituted monocyclic ß-lactams. Among several possible synthetic approaches, Staudinger cycloaddition proved to be the most promising method for initial ring formation, yielding monocyclic ß-lactams with different substituents at the C-4 position, a phthalimido-protected 3-amino group, and a (dimethoxy)benzyl protected ring nitrogen. Challenging deprotection methods were then investigated. Oxidative cleavage with cerium ammonium nitrate and ammonia-free Birch reduction was found to be most effective for selective removal of ring nitrogen protection. Hydrazine hydrate was used for deprotection of the phthalimido group, and the procedure had to be modified by the addition of HCl in the case of aromatic substituents at the C-4 position. The presented methods and the synthesized 3-amino-4-substituted monocyclic ß-lactam derivatives are an important step toward new ß-lactams with potential pharmacological activities.
Asunto(s)
Química Farmacéutica , beta-Lactamas/química , beta-Lactamas/síntesis química , Antibacterianos/farmacología , Ciclización , Nitrógeno/química , beta-Lactamas/farmacologíaRESUMEN
The multi-target-directed ligands (MTDLs) strategy is encouraged for the development of novel modulators targeting multiple pathways in the neurodegenerative cascade typical for Alzheimer's disease (AD). Based on the structure of an in-house irreversible monoamine oxidase B (MAO-B) inhibitor, we aimed to introduce a carbamate moiety on the aromatic ring to impart cholinesterase (ChE) inhibition, and to furnish multifunctional ligands targeting two enzymes that are intricately involved in AD pathobiology. In this study, we synthesized three dual hMAO-B/hBChE inhibitors 13-15, with compound 15 exhibiting balanced, low micromolar inhibition of hMAO-B (IC50 of 4.3 µM) and hBChE (IC50 of 8.5 µM). The docking studies and time-dependent inhibition of hBChE confirmed the initial expectation that the introduced carbamate moiety is responsible for covalent inhibition. Therefore, dual-acting compound 15 represents an excellent starting point for further optimization of balanced MTDLs.
Asunto(s)
Butirilcolinesterasa/química , Inhibidores de la Colinesterasa/farmacología , Diseño de Fármacos , Inhibidores de la Monoaminooxidasa/farmacología , Monoaminooxidasa/química , Piperidinas/química , Inhibidores de la Colinesterasa/química , Humanos , Ligandos , Simulación del Acoplamiento Molecular , Estructura Molecular , Inhibidores de la Monoaminooxidasa/química , Relación Estructura-ActividadRESUMEN
The immunoproteasome is a multicatalytic protease that is predominantly expressed in cells of hematopoietic origin. Its elevated expression has been associated with autoimmune diseases, various types of cancer, and inflammatory diseases. Selective inhibition of its catalytic activities is therefore a viable approach for the treatment of these diseases. However, the development of immunoproteasome-selective inhibitors with non-peptidic scaffolds remains a challenging task. We previously reported 7H-furo[3,2-g]chromen-7-one (psoralen)-based compounds with an oxathiazolone warhead as selective inhibitors of the chymotrypsin-like (ß5i) subunit of immunoproteasome. Here, we describe the influence of the electrophilic warhead variations at position 3 of the psoralen core on the inhibitory potencies. Despite mapping the chemical space with different warheads, all compounds showed decreased inhibition of the ß5i subunit of immunoproteasome in comparison to the parent oxathiazolone-based compound. Although suboptimal, these results provide crucial information about structure-activity relationships that will serve as guidance for the further design of (immuno)proteasome inhibitors.
Asunto(s)
Furocumarinas/síntesis química , Furocumarinas/farmacología , Inhibidores de Proteasoma/síntesis química , Inhibidores de Proteasoma/farmacología , Furocumarinas/química , Espectroscopía de Resonancia Magnética , Modelos Moleculares , Péptidos/química , Péptidos/farmacología , Complejo de la Endopetidasa Proteasomal/metabolismo , Inhibidores de Proteasoma/químicaRESUMEN
Brain butyrylcholinesterase (BChE) is an attractive target for drugs designed for the treatment of Alzheimer's disease (AD) in its advanced stages. It also potentially represents a biomarker for progression of this disease. Based on the crystal structure of previously described highly potent, reversible, and selective BChE inhibitors, we have developed the fluorescent probes that are selective towards human BChE. The most promising probes also maintain their inhibition of BChE in the low nanomolar range with high selectivity over acetylcholinesterase. Kinetic studies of probes reveal a reversible mixed inhibition mechanism, with binding of these fluorescent probes to both the free and acylated enzyme. Probes show environment-sensitive emission, and additionally, one of them also shows significant enhancement of fluorescence intensity upon binding to the active site of BChE. Finally, the crystal structures of probes in complex with human BChE are reported, which offer an excellent base for further development of this library of compounds.