RESUMO
The introduction of molecular complexity in an atom- and step-efficient manner remains an outstanding goal in modern synthetic chemistry. Artificial biosynthetic pathways are uniquely able to address this challenge by using enzymes to carry out multiple synthetic steps simultaneously or in a one-pot sequence1-3. Conducting biosynthesis ex vivo further broadens its applicability by avoiding cross-talk with cellular metabolism and enabling the redesign of key biosynthetic pathways through the use of non-natural cofactors and synthetic reagents4,5. Here we describe the discovery and construction of an enzymatic cascade to MK-1454, a highly potent stimulator of interferon genes (STING) activator under study as an immuno-oncology therapeutic6,7 (ClinicalTrials.gov study NCT04220866 ). From two non-natural nucleotide monothiophosphates, MK-1454 is assembled diastereoselectively in a one-pot cascade, in which two thiotriphosphate nucleotides are simultaneously generated biocatalytically, followed by coupling and cyclization catalysed by an engineered animal cyclic guanosine-adenosine synthase (cGAS). For the thiotriphosphate synthesis, three kinase enzymes were engineered to develop a non-natural cofactor recycling system in which one thiotriphosphate serves as a cofactor in its own synthesis. This study demonstrates the substantial capacity that currently exists to use biosynthetic approaches to discover and manufacture complex, non-natural molecules.
Assuntos
Guanosina , Nucleotidiltransferases , Adenosina , Animais , Interferons , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Nucleotidiltransferases/metabolismo , Transdução de SinaisRESUMO
A series of IDO1 inhibitors containing a decahydroquinoline, decahydro-1,6-naphthyridine, or octahydro-1H-pyrrolo[3,2-c]pyridine scaffold were identified with good cellular and human whole blood activity against IDO1. These inhibitors contain multiple chiral centers and all diastereomers were separated. The absolute stereochemistry of each isomers were not determined. Compounds 15 and 27 stood out as leads due to their good cellular as well as human whole blood IDO1 inhibition activity, low unbound clearance, and reasonable mean residence time in rat cassette PK studies.
Assuntos
Inibidores Enzimáticos/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Naftiridinas/farmacologia , Pirróis/farmacologia , Quinolinas/farmacologia , Animais , Domínio Catalítico , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/metabolismo , Inibidores Enzimáticos/farmacocinética , Células HeLa , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/química , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Simulação de Acoplamento Molecular , Naftiridinas/síntese química , Naftiridinas/metabolismo , Naftiridinas/farmacocinética , Pirróis/síntese química , Pirróis/metabolismo , Pirróis/farmacocinética , Quinolinas/síntese química , Quinolinas/metabolismo , Quinolinas/farmacocinética , Ratos , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
PI3K-δ mediates key immune cell signaling pathways and is a target of interest for treatment of oncological and immunological disorders. Here we describe the discovery and optimization of a novel series of PI3K-δ selective inhibitors. We first identified hits containing an isoindolinone scaffold using a combined ligand- and receptor-based virtual screening workflow, and then improved potency and selectivity guided by structural data and modeling. Careful optimization of molecular properties led to compounds with improved permeability and pharmacokinetic profile, and high potency in a whole blood assay.
Assuntos
Classe I de Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Descoberta de Drogas , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Ftalimidas/farmacologia , Classe I de Fosfatidilinositol 3-Quinases/metabolismo , Relação Dose-Resposta a Droga , Avaliação Pré-Clínica de Medicamentos , Humanos , Estrutura Molecular , Inibidores de Fosfoinositídeo-3 Quinase/síntese química , Inibidores de Fosfoinositídeo-3 Quinase/química , Ftalimidas/síntese química , Ftalimidas/química , Relação Estrutura-AtividadeRESUMO
A novel series of IDO1 inhibitors have been identified with good IDO1 Hela cell and human whole blood activity. These inhibitors contain an indoline or a 3-azaindoline scaffold. Their structure-activity-relationship studies have been explored. Compounds 37 and 41 stood out as leads due to their good potency in IDO1 Hela assay, good IDO1 unbound hWB IC50s, reasonable unbound clearance, and good MRT in rat and dog PK studies.
Assuntos
Compostos Aza/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/antagonistas & inibidores , Indóis/farmacologia , Animais , Compostos Aza/síntese química , Compostos Aza/química , Cães , Relação Dose-Resposta a Droga , Humanos , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismo , Indóis/síntese química , Indóis/química , Masculino , Estrutura Molecular , Ratos , Ratos Wistar , Relação Estrutura-AtividadeRESUMO
A high-throughput screening (HTS) campaign identified a class of heteroaryl piperazines with excellent baseline affinity and selectivity for phosphoinositide 3-kinase δ (PI3Kδ) over closely related isoforms. Rapid evaluation and optimization of structure-activity relationships (SAR) for this class, leveraging the modular nature of this scaffold, facilitated development of this hit class into a series of potent and selective inhibitors of PI3Kδ. This effort culminated in the identification of 29, which displayed excellent potency in enzyme and cell-based assays, as well as favorable pharmacokinetic and off-target profiles.
Assuntos
Classe I de Fosfatidilinositol 3-Quinases/antagonistas & inibidores , Ensaios de Triagem em Larga Escala/métodos , Piperazinas/uso terapêutico , Inibidores de Proteínas Quinases/uso terapêutico , Humanos , Piperazinas/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Relação Estrutura-AtividadeRESUMO
A series of 4, 4-disubstituted proline analogs were designed, synthesized, and tested for selective inhibition of blood coagulation factor XIa in search of new non-vitamin K antagonists based oral anticoagulants for potential prevention and treatment of thrombotic diseases. Starting from a potent thrombin (FIIa) inhibitor chemotype with FIIa IC50 = 1 nM and FXIa IC50 = 160 nM, medicinal chemistry iterations guided by molecular modeling and structure-based drug design led to steady improvement of FXIa potency while dialing down thrombin activity and improving selectivity. Through this exercise, a thousand-fold enhancement of selectivity over thrombin was achieved with some analogs carrying factor XIa inhibition potencies in the 10 nM range. In this communication, we discuss the design principles and structure activity relationship (SAR) of these novel FXIa selective inhibitors.
Assuntos
Anticoagulantes/farmacologia , Desenho de Fármacos , Fator XIa/antagonistas & inibidores , Prolina/farmacologia , Anticoagulantes/síntese química , Anticoagulantes/química , Relação Dose-Resposta a Droga , Fator XIa/metabolismo , Humanos , Estrutura Molecular , Prolina/síntese química , Prolina/química , Relação Estrutura-AtividadeRESUMO
Two orthogonal approaches for hit identification in drug discovery are large-scale in vitro and in silico screening. In recent years, due to the emergence of new targets and a rapid increase in the size of the readily synthesizable chemical space, there is a growing emphasis on the integration of the two techniques to improve the hit finding efficiency. Here, we highlight three examples of drug discovery projects at Merck & Co., Inc., Kenilworth, NJ, USA in which different virtual screening (VS) techniques, each specifically tailored to leverage knowledge available for the target, were utilized to augment the selection of high-quality chemical matter for in vitro assays and to enhance the diversity and tractability of hits. Central to success is a fully integrated workflow combining in silico and experimental expertise at every stage of the hit identification process. We advocate that workflows encompassing VS as part of an integrated hit finding plan should be widely adopted to accelerate hit identification and foster cross-functional collaborations in modern drug discovery.
Assuntos
Descoberta de Drogas , Ensaios de Triagem em Larga Escala , Simulação por Computador , Bibliotecas de Moléculas PequenasRESUMO
PI3Kδ mediates key immune cell signaling pathways and is a target of interest for multiple indications in immunology and oncology. Here we report a structure-based scaffold-hopping strategy for the design of chemically diverse PI3Kδ inhibitors. Using this strategy, we identified several scaffolds that can be combined to generate new PI3Kδ inhibitors with high potency and isoform selectivity. In particular, an oxindole-based scaffold was found to impart exquisite selectivity when combined with several hinge binding motifs.
Assuntos
Desenho de Fármacos , Oxindóis/farmacologia , Fosfatidilinositol 3-Quinases/metabolismo , Inibidores de Fosfoinositídeo-3 Quinase/farmacologia , Sítios de Ligação/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Estrutura Molecular , Oxindóis/síntese química , Oxindóis/química , Inibidores de Fosfoinositídeo-3 Quinase/síntese química , Inibidores de Fosfoinositídeo-3 Quinase/química , Relação Estrutura-AtividadeRESUMO
Interleukin-1 receptor associated kinase 4 (IRAK4) has been implicated in IL-1R and TLR based signaling. Therefore selective inhibition of the kinase activity of this protein represents an attractive target for the treatment of inflammatory diseases. Medicinal chemistry optimization of high throughput screening (HTS) hits with the help of structure based drug design led to the identification of orally-bioavailable quinazoline based IRAK4 inhibitors with excellent pharmacokinetic profile and kinase selectivity. These highly selective IRAK4 compounds show activity in vivo via oral dosing in a TLR7 driven model of inflammation.
Assuntos
Inflamação/tratamento farmacológico , Quinases Associadas a Receptores de Interleucina-1/antagonistas & inibidores , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacologia , Administração Oral , Animais , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Ensaios de Triagem em Larga Escala , Imidazóis/farmacologia , Inflamação/enzimologia , Quinases Associadas a Receptores de Interleucina-1/metabolismo , Interleucina-6/antagonistas & inibidores , Interleucina-6/biossíntese , Modelos Moleculares , Estrutura Molecular , Inibidores de Proteínas Quinases/administração & dosagem , Inibidores de Proteínas Quinases/química , Quinazolinas/administração & dosagem , Quinazolinas/química , Ratos , Ratos Endogâmicos Lew , Relação Estrutura-AtividadeRESUMO
HCV infections are the leading causes for hepatocellular carcinoma and liver transplantation in the United States. Recent advances in drug discovery have identified direct acting antivirals which have significantly improved cure rates in patients. Current efforts are directed towards identification of novel direct acting antiviral targeting different mechanism of actions which could become part of all oral therapies. We recently disclosed the identification of a novel tricyclic indole derived inhibitors of HCV NS5B polymerase that bound to the enzyme close to the active site. In this manuscript we describe further optimization of potency and pharmacokinetics (PK) of these inhibitors to identify compounds in low nM potency against gt-1b. These analogs also demonstrate excellent PK in rats and monkeys when administered as a dimethyl ethyl amino ester prodrug.
Assuntos
Ésteres/farmacocinética , Hepacivirus/efeitos dos fármacos , Indóis/farmacocinética , Proteínas não Estruturais Virais/antagonistas & inibidores , Administração Oral , Animais , Descoberta de Drogas , Ésteres/química , Haplorrinos , Hepacivirus/enzimologia , Humanos , Indóis/química , Pró-Fármacos/farmacologia , Ratos , Relação Estrutura-AtividadeRESUMO
The discovery of lead compound 2e was described. Its covalent binding to HCV NS5B polymerase enzyme was investigated by X-ray analysis. The results of distribution, metabolism and pharmacokinetics were reported. Compound 2e was demonstrated to be potent (replicon GT-1b EC50 = 0.003 µM), highly selective, and safe in in vitro and in vivo assays.
Assuntos
Inibidores Enzimáticos/química , Hepacivirus/enzimologia , Indóis/química , Quinolinas/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Animais , Cristalografia por Raios X , Cães , Avaliação Pré-Clínica de Medicamentos , Ativação Enzimática/efeitos dos fármacos , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacocinética , Inibidores Enzimáticos/farmacologia , Haplorrinos , Humanos , Indóis/síntese química , Indóis/farmacocinética , Indóis/farmacologia , Masculino , Simulação de Dinâmica Molecular , Ligação Proteica , Estrutura Terciária de Proteína , Quinolinas/síntese química , Quinolinas/farmacocinética , Quinolinas/farmacologia , Ratos , Ratos Sprague-Dawley , Proteínas não Estruturais Virais/metabolismoRESUMO
The characterization of HCV genome has identified various vital functional proteins involved in the life cycle of hepatitis C virus. This has resulted in many novel enzymatic targets that are potential for development of therapeutic agents. The HCV RNA dependent RNA polymerase (HCV NS5B) is one such essential enzyme for HCV replication that has been well characterized and studied by various groups to develop novel therapies for hepatitis C. In this paper, we describe our efforts towards the identification and structure-activity relationship (SAR) of novel tricyclic indole derivatives that bind close to the palm site of the NS5B polymerase. X-ray crystal structure of an inhibitor bound to the polymerase is also described.
Assuntos
Antivirais/química , Antivirais/farmacologia , Hepacivirus/enzimologia , Indóis/química , Indóis/farmacologia , RNA Polimerase Dependente de RNA/antagonistas & inibidores , Sítios de Ligação , Cristalografia por Raios X , Hepacivirus/química , Hepatite C/tratamento farmacológico , Hepatite C/virologia , Humanos , Simulação de Acoplamento Molecular , RNA Polimerase Dependente de RNA/química , RNA Polimerase Dependente de RNA/metabolismo , Relação Estrutura-AtividadeRESUMO
Development of SAR at the C2 position of indole lead 1, a palm site inhibitor of HCV NS5B polymerase (NS5B IC(50)=0.053µM, replicon EC(50)=4.8µM), is described. Initial screening identified an acyl sulfonamide moiety as an isostere for the C2 carboxylic acid group. Further SAR investigation resulted in identification of acyl sufonamide analog 7q (NS5B IC(50)=0.039µM, replicon EC(50)=0.011µM) with >100-fold improved replicon activity.
Assuntos
Antivirais/farmacologia , Indóis/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Química Farmacêutica/métodos , Cristalografia por Raios X/métodos , Desenho de Fármacos , Humanos , Ligação de Hidrogênio , Concentração Inibidora 50 , Modelos Químicos , Modelos Moleculares , Conformação Molecular , Relação Estrutura-Atividade , Sulfonamidas/químicaRESUMO
3,3-Disubstituted oxetanes have been utilized as bioisosteres for gem-dimethyl and cyclobutane functionalities. We report the discovery of a novel class of oxetane indole-amine 2,3-dioxygenase (IDO1) inhibitors suitable for Q3W (once every 3 weeks) oral and parenteral dosing. A diamide class of IDO inhibitors was discovered through an automated ligand identification system (ALIS). Installation of an oxetane and fluorophenyl dramatically improved the potency. Identification of a biaryl moiety as an unconventional amide isostere addressed the metabolic liability of amide hydrolysis. Metabolism identification (Met-ID)-guided target design and the introduction of polarity resulted in the discovery of potent IDO inhibitors with excellent pharmacokinetic (PK) profiles in multiple species. To enable rapid synthesis of the key oxetane intermediate, a novel oxetane ring cyclization was also developed, as well as optimization of a literature route on kg scale. These IDO inhibitors may enable unambiguous proof-of-concept testing for the IDO1 inhibition mechanism for oncology.
Assuntos
Inibidores Enzimáticos , Éteres Cíclicos , Amidas , Ciclização , Inibidores Enzimáticos/farmacologia , Indolamina-Pirrol 2,3,-Dioxigenase/metabolismoRESUMO
Stereochemically and structurally complex cyclic dinucleotide-based stimulator of interferon genes (STING) agonists were designed and synthesized to access a previously unexplored chemical space. The assessment of biochemical affinity and cellular potency, along with computational, structural, and biophysical characterization, was applied to influence the design and optimization of novel STING agonists, resulting in the discovery of MK-1454 as a molecule with appropriate properties for clinical development. When administered intratumorally to immune-competent mice-bearing syngeneic tumors, MK-1454 exhibited robust tumor cytokine upregulation and effective antitumor activity. Tumor shrinkage in mouse models that are intrinsically resistant to single-agent therapy was further enhanced when treating the animals with MK-1454 in combination with a fully murinized antimouse PD-1 antibody, mDX400. These data support the development of STING agonists in combination with pembrolizumab (humanized anti-PD-1 antibody) for patients with tumors that are partially responsive or nonresponsive to single-agent anti-PD-1 therapy.
Assuntos
Proteínas de Membrana , Neoplasias , Animais , Citocinas , Humanos , Imunoterapia/métodos , Interferons , Camundongos , Neoplasias/tratamento farmacológicoRESUMO
Inhibition of leucine-rich repeat kinase 2 (LRRK2) kinase activity represents a genetically supported, chemically tractable, and potentially disease-modifying mechanism to treat Parkinson's disease. Herein, we describe the optimization of a novel series of potent, selective, central nervous system (CNS)-penetrant 1-heteroaryl-1H-indazole type I (ATP competitive) LRRK2 inhibitors. Type I ATP-competitive kinase physicochemical properties were integrated with CNS drug-like properties through a combination of structure-based drug design and parallel medicinal chemistry enabled by sp3-sp2 cross-coupling technologies. This resulted in the discovery of a unique sp3-rich spirocarbonitrile motif that imparted extraordinary potency, pharmacokinetics, and favorable CNS drug-like properties. The lead compound, 25, demonstrated exceptional on-target potency in human peripheral blood mononuclear cells, excellent off-target kinase selectivity, and good brain exposure in rat, culminating in a low projected human dose and a pre-clinical safety profile that warranted advancement toward pre-clinical candidate enabling studies.
Assuntos
Doença de Parkinson , Ratos , Humanos , Animais , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina , Doença de Parkinson/tratamento farmacológico , Indazóis/farmacologia , Indazóis/uso terapêutico , Leucócitos Mononucleares/metabolismo , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Inibidores de Proteínas Quinases/química , Encéfalo/metabolismo , Trifosfato de AdenosinaRESUMO
The leucine-rich repeat kinase 2 (LRRK2) protein has been genetically and functionally linked to Parkinson's disease (PD), a disabling and progressive neurodegenerative disorder whose current therapies are limited in scope and efficacy. In this report, we describe a rigorous hit-to-lead optimization campaign supported by structural enablement, which culminated in the discovery of brain-penetrant, candidate-quality molecules as represented by compounds 22 and 24. These compounds exhibit remarkable selectivity against the kinome and offer good oral bioavailability and low projected human doses. Furthermore, they showcase the implementation of stereochemical design elements that serve to enable a potency- and selectivity-enhancing increase in polarity and hydrogen bond donor (HBD) count while maintaining a central nervous system-friendly profile typified by low levels of transporter-mediated efflux and encouraging brain penetration in preclinical models.
Assuntos
Antiparkinsonianos/síntese química , Antiparkinsonianos/farmacologia , Encéfalo/metabolismo , Serina-Treonina Proteína Quinase-2 com Repetições Ricas em Leucina/antagonistas & inibidores , Quinazolinas/síntese química , Quinazolinas/farmacologia , Antiparkinsonianos/farmacocinética , Disponibilidade Biológica , Desenho de Fármacos , Humanos , Modelos Moleculares , Inibidores de Proteínas Quinases/farmacologia , Quinazolinas/farmacocinética , Relação Estrutura-AtividadeRESUMO
SAR development of indole-based palm site inhibitors of HCV NS5B polymerase exemplified by initial indole lead 1 (NS5B IC(50)=0.9 µM, replicon EC(50)>100 µM) is described. Structure-based drug design led to the incorporation of novel heterocyclic moieties at the indole C3-position which formed a bidentate interaction with the protein backbone. SAR development resulted in leads 7q (NS5B IC(50)=0.032 µM, replicon EC(50)=1.4 µM) and 7r (NS5B IC(50)=0.017 µM, replicon EC(50)=0.3 µM) with improved enzyme and replicon activity.
Assuntos
Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Compostos Heterocíclicos/farmacologia , Indóis/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Ácidos Carboxílicos , Domínio Catalítico/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Indóis/síntese química , Indóis/química , Modelos Moleculares , Estrutura Molecular , Estereoisomerismo , Relação Estrutura-Atividade , Proteínas não Estruturais Virais/metabolismoRESUMO
Arginase (EC 3.5.3.1) is an aminohydrolase that acts on L-arginine to produce urea and ornithine. Two isotypes of the enzyme are found in humans. Type I is predominantly produced in the liver and is a homotrimer of 35â kDa subunits. Human arginase (hArginase) I is seen to be up-regulated in many diseases and is a potential therapeutic target for many diverse indications. Previous reports of crystallization and structure determination of hArginase have always included inhibitors of the enzyme: here, the first case of a true apo crystal form of the enzyme which is suitable for small-molecule soaking is reported. The crystals belonged to space group P2(1)2(1)2(1) and have approximate unit-cell parameters a=53, b=67.5, c=250â Å. The crystals showed slightly anisotropic diffraction to beyond 2.0â Å resolution.