RESUMO
Tyrosine phosphatase SHP2 is a proto-oncogenic protein involved in cell growth and differentiation via diverse intracellular signaling pathways. With the scope of identifying new SHP2 allosteric inhibitors, we report here the development and optimization of a high-throughput "Direct-to-Biology" (D2B) workflow including the synthesis and the biological evaluation of the reaction crude, thus eliminating the need for purification. During this labor-saving procedure, the structural diversity was introduced through a SNAr reaction. A wide array of analogues with good chemical purity was generated, allowing the obtention of reliable biological data which validated this efficient technique. This approach enabled the fast evaluation of a variety of structurally diverse fragments leading to nanomolar SHP2 allosteric inhibitors and a new series bearing a novel bicyclo[3.1.0]hexane moiety.
Assuntos
Inibidores Enzimáticos , Transdução de Sinais , Inibidores Enzimáticos/química , Proliferação de Células , Diferenciação Celular , BiologiaRESUMO
Zika virus (ZIKV) is a member of the Flaviviridae family that can cause neurological disorders and congenital malformations. The NS2B-NS3 viral serine protease is an attractive target for the development of new antiviral agents against ZIKV. We report here a SAR study on a series of substrate-like linear tripeptides that inhibit in a non-covalent manner the NS2B-NS3 protease. Optimization of the residues at positions P1, P2, P3 and of the N-terminal and C-terminal portions of the tripeptide allowed the identification of inhibitors with sub-micromolar potency with phenylglycine as arginine-mimicking group and benzylamide as C-terminal fragment. Further SAR exploration and application of these structural changes to a series of peptides having a 4-substituted phenylglycine residue at the P1 position led to potent compounds showing double digit nanomolar inhibition of the Zika protease (IC50 = 30 nM) with high selectivity against trypsin-like proteases and the proteases of other flavivirus, such as Dengue 2 virus (DEN2V) and West Nile virus (WNV).
Assuntos
Antivirais/farmacologia , Peptídeos/farmacologia , Inibidores de Proteases/farmacologia , Proteínas não Estruturais Virais/antagonistas & inibidores , Zika virus/efeitos dos fármacos , Antivirais/síntese química , Antivirais/química , Vírus da Dengue/efeitos dos fármacos , Relação Dose-Resposta a Droga , Humanos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Peptídeos/síntese química , Peptídeos/química , Inibidores de Proteases/síntese química , Inibidores de Proteases/química , RNA Helicases/antagonistas & inibidores , RNA Helicases/metabolismo , Serina Endopeptidases/metabolismo , Relação Estrutura-Atividade , Proteínas não Estruturais Virais/metabolismo , Vírus do Nilo Ocidental/efeitos dos fármacos , Zika virus/enzimologiaRESUMO
The identification of a new series of growth inhibitors of Trypanosoma cruzi, the causative agent of Chagas' disease, is described. In vitro screening of a subset of compounds from our in-house compound collection against the parasite led to the identification of hit compound 1 with low micromolar inhibition of T. cruzi growth. SAR exploration on the hit compound led to the identification of compounds that show nanomolar parasite growth inhibition (T. cruzi EC50 ≤ 100 nM) and no cytotoxicity in human cells (HeLa CC50 > 50 µM). Further investigation identified CYP51 inhibition (compound 11 CYP51 IC50 52 nM) as a possible mechanism of action of this new class of anti-parasitic agents.
Assuntos
Descoberta de Drogas , Inibidores do Crescimento/farmacologia , Piridinas/farmacologia , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Relação Dose-Resposta a Droga , Inibidores do Crescimento/síntese química , Inibidores do Crescimento/química , Humanos , Estrutura Molecular , Testes de Sensibilidade Parasitária , Piridinas/síntese química , Piridinas/química , Relação Estrutura-Atividade , Tripanossomicidas/síntese química , Tripanossomicidas/químicaRESUMO
A previous publication from our laboratory reported the identification of a new class of 2-(1H-imidazo-2-yl)piperazines as potent T. brucei growth inhibitors as potential treatment for Human African Trypanosomiasis (HAT). This work describes the structure-activity relationship (SAR) around the hit compound 1, which led to the identification of the optimized compound 18, a single digit nanomolar inhibitor (EC50 7 nM), not cytotoxic and with optimal in vivo profile that made it a suitable candidate for efficacy studies in a mouse model mimicking the second stage of disease.
Assuntos
Inibidores do Crescimento/química , Piperazinas/química , Tripanossomicidas/química , Trypanosoma brucei brucei/efeitos dos fármacos , Tripanossomíase Africana/tratamento farmacológico , Sobrevivência Celular/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Inibidores do Crescimento/farmacologia , Células Endoteliais da Veia Umbilical Humana , Humanos , Isomerismo , Morfolinas/química , Piperazinas/farmacologia , Quinolinas/química , Relação Estrutura-Atividade , Tripanossomicidas/farmacologiaRESUMO
The identification of a new series of growth inhibitors of Trypanosoma brucei rhodesiense, causative agent of Human African Trypanosomiasis (HAT), is described. A selection of compounds from our in-house compound collection was screened in vitro against the parasite leading to the identification of compounds with nanomolar inhibition of T. brucei growth. Preliminary SAR on the hit compound led to the identification of compound 34 that shows low nanomolar parasite growth inhibition (T. brucei EC50 5â¯nM), is not cytotoxic (HeLa CC50â¯>â¯25,000â¯nM) and is selective over other parasites, such as Trypanosoma cruzi and Plasmodium falciparum (T. cruzi EC50 8120â¯nM, P. falciparum EC50 3624â¯nM).
Assuntos
Piperazinas/química , Piperazinas/farmacologia , Tripanossomicidas/química , Tripanossomicidas/farmacologia , Trypanosoma brucei brucei/efeitos dos fármacos , Tripanossomíase Africana/tratamento farmacológico , Células HeLa , Humanos , Imidazóis/química , Imidazóis/farmacologia , Malária Falciparum/tratamento farmacológico , Plasmodium falciparum/efeitos dos fármacos , Relação Estrutura-Atividade , Trypanosoma brucei brucei/crescimento & desenvolvimento , Tripanossomíase Africana/parasitologiaRESUMO
Protein tyrosine phosphatase SHP2 is an oncogenic protein that can regulate different cytokine receptor and receptor tyrosine kinase signaling pathways. We report here the identification of a novel series of SHP2 allosteric inhibitors having an imidazopyrazine 6,5-fused heterocyclic system as the central scaffold that displays good potency in enzymatic and cellular assays. SAR studies led to the identification of compound 8, a highly potent SHP2 allosteric inhibitor. X-ray studies showed novel stabilizing interactions with respect to known SHP2 inhibitors. Subsequent optimization allowed us to identify analogue 10, which possesses excellent potency and a promising PK profile in rodents.
RESUMO
Smoothened (Smo) antagonists are emerging as new therapies for the treatment of neoplasias with aberrantly reactivated hedgehog (Hh) signaling pathway. A novel series of 4-[3-(quinolin-2-yl)-1,2,4-oxadiazol-5-yl]piperazinyl ureas as smoothened antagonists was recently described, herein the series has been further optimized through the incorporation of a basic amine into the urea. This development resulted in identification of some exceptionally potent smoothened antagonists with low serum shifts, however, reductive ring opening on the 1,2,4-oxadiazole in rats limits the applicability of these compounds in in vivo studies.
Assuntos
Amidas/farmacologia , Piperazinas/farmacologia , Receptores Acoplados a Proteínas G/antagonistas & inibidores , Amidas/síntese química , Amidas/química , Estrutura Molecular , Piperazinas/síntese química , Piperazinas/química , Receptor Smoothened , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
The Hedgehog (Hh-) signalling pathway is a key developmental pathway and there is a growing body of evidence showing that this pathway is aberrantly reactivated in a number of human tumors. Novel agents capable of inhibiting this pathway are sought, and an entirely novel series of smoothened (Smo) antagonists capable of inhibiting the pathway have been identified through uHTS screening. Extensive exploration of the scaffold identified the key functionalities necessary for potency, enabling potent nanomolar Smo antagonists like 91 and 94 to be developed. Optimization resulted in the most advanced compounds displaying low serum shift, clean off-targets profile, and moderate clearance in both rats and dogs. These compounds are valuable tools with which to probe the biology of the Hh-pathway.
Assuntos
Proteínas Hedgehog/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Ureia/farmacologia , Animais , Cães , Relação Dose-Resposta a Droga , Proteínas Hedgehog/metabolismo , Humanos , Microssomos/efeitos dos fármacos , Microssomos/metabolismo , Estrutura Molecular , Ratos , Estereoisomerismo , Relação Estrutura-Atividade , Ureia/análogos & derivados , Ureia/químicaRESUMO
A novel hexahydrobenzonaphthyridinone PARP-1 pharmacophore is reported, subsequent SAR exploration around this scaffold led to selective PARP-1 inhibitors with low nanomolar enzyme potency, displaying good cellular activity and promising rat PK properties.
Assuntos
Inibidores Enzimáticos/química , Naftiridinas/química , Inibidores de Poli(ADP-Ribose) Polimerases , Animais , Descoberta de Drogas , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacocinética , Microssomos Hepáticos/metabolismo , Naftiridinas/síntese química , Naftiridinas/farmacocinética , Poli(ADP-Ribose) Polimerases/metabolismo , Ratos , Relação Estrutura-AtividadeRESUMO
A potent series of substituted 2-phenyl-2H-indazole-7-carboxamides were synthesized and evaluated as inhibitors of poly (ADP-ribose) polymerase (PARP). This extensive SAR exploration culminated with the identification of substituted 5-fluoro-2-phenyl-2H-indazole-7-carboxamide analog 48 which displayed excellent PARP enzyme inhibition with IC(50)=4nM, inhibited proliferation of cancer cell lines deficient in BRCA-1 with CC(50)=42nM and showed encouraging pharmacokinetic properties in rats compared to the lead 6.
Assuntos
Amidas/síntese química , Antineoplásicos/síntese química , Azetidinas/síntese química , Inibidores Enzimáticos/síntese química , Indazóis/síntese química , Inibidores de Poli(ADP-Ribose) Polimerases , Amidas/química , Amidas/farmacologia , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Azetidinas/química , Azetidinas/farmacologia , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Células HeLa , Humanos , Indazóis/química , Indazóis/farmacologia , Poli(ADP-Ribose) Polimerases/metabolismo , Ratos , Relação Estrutura-Atividade , Ubiquitina-Proteína Ligases/deficiência , Ubiquitina-Proteína Ligases/genética , Ubiquitina-Proteína Ligases/metabolismoRESUMO
Chronic hepatitis C virus (HCV) infections are a significant medical problem worldwide. The NS5B Polymerase of HCV plays a central role in virus replication and is a prime target for the discovery of new treatment options. We recently disclosed 1H-benzo[de]isoquinoline-1,3(2H)-diones as allosteric inhibitors of NS5B Polymerase. Structural and SAR information guided us in the modification of the core structure leading to new templates with improved activity and toxicity/activity window.
Assuntos
Antivirais/síntese química , Inibidores Enzimáticos/síntese química , Proteínas não Estruturais Virais/antagonistas & inibidores , Regulação Alostérica , Antivirais/química , Antivirais/farmacologia , Desenho de Fármacos , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Humanos , Conformação Molecular , Estrutura Terciária de Proteína , Relação Estrutura-Atividade , Proteínas não Estruturais Virais/metabolismoRESUMO
The NRF2-ARE pathway is an intrinsic mechanism of defense against oxidative stress. Inhibition of the interaction between NRF2 and its main negative regulator KEAP1 is an attractive strategy toward neuroprotective agents. We report here the identification of nonacidic tetrahydroisoquinolines (THIQs) that inhibit the KEAP1/NRF2 protein-protein interaction. Peptide SAR at one residue is utilized as a tool to probe structural changes within a specific pocket of the KEAP1 binding site. We used structural information from peptide screening at the P2 pocket, noncovalent small-molecules inhibitors, and the outcome from an explorative SAR at position 5 of THIQs to identify a series of neutral THIQ analogs that bind to KEAP1 in the low micromolar range. These analogs establish new H-bond interactions at the P3 and P2 pockets allowing the replacement of the carboxylic acid functionality by a neutral primary carboxamide. X-ray crystallographic studies reveal the novel binding mode of these molecules to KEAP1.
RESUMO
Histone deacetylase (HDAC) inhibition causes hyperacetylation of histones leading to differentiation, growth arrest and apoptosis of malignant cells, representing a new strategy in cancer therapy. Many of the known HDAC inhibitors (HDACi) that are in clinical trials possess a hydroxamic acid, that is a strong Zn(2+) binding group, thereby inhibiting some of the class I and class II isoforms. Herein we describe the identification of a selective class I HDAC inhibitor bearing a primary carboxamide moiety as zinc binding group. This HDACi displays good antiproliferative activity against multiple cancer cell lines, and demonstrates efficacy in a xenograft model comparable to vorinostat.
Assuntos
Amidas/química , Antineoplásicos/química , Inibidores Enzimáticos/química , Inibidores de Histona Desacetilases , Zinco/química , Amidas/síntese química , Amidas/farmacologia , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacologia , Histona Desacetilases/metabolismo , Humanos , Ácidos Hidroxâmicos/farmacologia , Camundongos , Camundongos Nus , Relação Estrutura-Atividade , Vorinostat , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
A novel series of pyrazolo[1,5-a]quinazolin-5(4H)-one derivatives proved to be a potent class of PARP-1 inhibitors. An extensive SAR around the 3-position of pyrazole in the scaffold led to the discovery of amides derivatives as low nanomolar PARP-1 inhibitors.
Assuntos
Inibidores Enzimáticos/síntese química , Inibidores de Poli(ADP-Ribose) Polimerases , Pirazóis/síntese química , Amidas/química , Química Orgânica/métodos , Química Farmacêutica/métodos , Desenho de Fármacos , Avaliação Pré-Clínica de Medicamentos , Inibidores Enzimáticos/farmacologia , Células HeLa , Humanos , Concentração Inibidora 50 , Modelos Químicos , Estrutura Molecular , Pirazóis/farmacologia , Quinazolinonas/síntese química , Quinazolinonas/farmacologia , Relação Estrutura-AtividadeRESUMO
The application of class I HDAC inhibitors as cancer therapies is well established, but more recently their development for nononcological indications has increased. We report here on the generation of improved class I selective human HDAC inhibitors based on an ethylketone zinc binding group (ZBG) in place of the hydroxamic acid that features the majority of HDAC inhibitors. We also describe a novel set of HDAC3 isoform selective inhibitors that show stronger potency and selectivity than the most commonly used HDAC3 selective tool compound RGFP966. These compounds are again based on an alternative ZBG with respect to the ortho-anilide that is featured in HDAC3 selective compounds reported to date.
RESUMO
5-(Trifluoroacetyl)thiophene-2-carboxamides were found to be potent and selective class II HDAC inhibitors. This paper describes their further development and the investigation on the cause for the lack of cell-based activity. A rapid screening assay was set up which enabled the identification of more metabolic stable compounds as potent and selective class II HDAC inhibitors.
Assuntos
Amidas/síntese química , Amidas/farmacologia , Inibidores de Histona Desacetilases , Tiofenos/síntese química , Tiofenos/farmacologia , Amidas/química , Hidrocarboneto de Aril Hidroxilases/antagonistas & inibidores , Citocromo P-450 CYP2C9 , Desenho de Fármacos , Células HCT116 , Células HeLa , Hepatócitos/efeitos dos fármacos , Histona Desacetilases/classificação , Humanos , Microssomos Hepáticos/efeitos dos fármacos , Estrutura Molecular , Relação Estrutura-Atividade , Tiofenos/química , Tubulina (Proteína)/efeitos dos fármacosRESUMO
The identification of class II HDAC inhibitors has been hampered by lack of efficient enzyme assays, in the preceding paper two assays have been developed to improve the efficiency of these enzymes: mutating an active site histidine to tyrosine, or by the use of a trifluoroacetamide lysine substrate, allowing screening to identify class II HDAC inhibitors. Herein, 2-trifluoroacetylthiophenes have been demonstrated to inhibit class II HDACs, resulting in the development of a series of 5-(trifluoroacetyl)thiophene-2-carboxamides as novel, potent and selective class II HDAC inhibitors. X-ray crystal structures of the HDAC 4 catalytic domain with a bound inhibitor demonstrate these compounds are active site inhibitors and bind in their hydrated form.
Assuntos
Desenho de Fármacos , Inibidores Enzimáticos/síntese química , Inibidores de Histona Desacetilases , Tiofenos/síntese química , Sítios de Ligação , Cristalografia por Raios X , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Histona Desacetilases/classificação , Conformação Molecular , Estrutura Molecular , Relação Estrutura-Atividade , Tiofenos/química , Tiofenos/farmacologia , Zinco/química , Zinco/metabolismoRESUMO
The identification of a new series of P. falciparum growth inhibitors is described. Starting from a series of known human class I HDAC inhibitors a SAR exploration based on growth inhibitory activity in parasite and human cells-based assays led to the identification of compounds with submicromolar inhibition of P. falciparum growth (EC50 < 500 nM) and good selectivity over the activity of human HDAC in cells (up to >50-fold). Inhibition of parasital HDACs as the mechanism of action of this new class of selective growth inhibitors is supported by hyperacetylation studies.
RESUMO
The design of a series of peptidomimetic inhibitors of the hepatitis C virus NS3 protease is described. These inhibitors feature an indoline-2-carboxamide as a novel heterocyclic replacement for the P3 amino acid residue and N-terminal capping group of tripeptide based inhibitors. The crystal structure of the ternary NS3/NS4A/inhibitor complex for the most active molecule in this series highlights its suitability as an N-terminal capping group of a dipeptide inhibitor of the NS3 protease.
Assuntos
Antivirais/síntese química , Hepacivirus/enzimologia , Indóis/síntese química , Oligopeptídeos/química , Proteínas não Estruturais Virais/antagonistas & inibidores , Proteínas não Estruturais Virais/química , Antivirais/química , Cristalografia por Raios X , Indóis/química , Modelos Moleculares , Mimetismo Molecular , Estrutura Molecular , Ligação Proteica , EstereoisomerismoRESUMO
5-Aryl-2-(trifluoroacetyl)thiophenes were identified as a new series of class II HDAC inhibitors (HDACi). Further development of this new series led to compounds such as 6h, a potent inhibitor of HDAC4 and HDAC6 (HDAC4 WT IC(50) = 310 nM, HDAC6 IC(50) = 70 nM) that displays 40-fold selectivity over HDAC1 and improved stability in HCT116 cancer cells (t(1/2) = 11 h). Compounds 6h and 2 show inhibition of alpha-tubulin deacetylation in HCT116 cells at 1 microM concentration and antiproliferation effects only at concentrations where inhibition of histone H3 deacetylation is observed.