RESUMO
The resistance of methicillin-resistant Staphylococcus aureus (MRSA) to all ß-lactam classes limits treatment options for serious infections involving this organism. Our goal is to discover new agents that restore the activity of ß-lactams against MRSA, an approach that has led to the discovery of two classes of natural product antibiotics, a cyclic depsipeptide (krisynomycin) and a lipoglycopeptide (actinocarbasin), which potentiate the activity of imipenem against MRSA strain COL. We report here that these imipenem synergists are inhibitors of the bacterial type I signal peptidase SpsB, a serine protease that is required for the secretion of proteins that are exported through the Sec and Tat systems. A synthetic derivative of actinocarbasin, M131, synergized with imipenem both in vitro and in vivo with potent efficacy. The in vitro activity of M131 extends to clinical isolates of MRSA but not to a methicillin-sensitive strain. Synergy is restricted to ß-lactam antibiotics and is not observed with other antibiotic classes. We propose that the SpsB inhibitors synergize with ß-lactams by preventing the signal peptidase-mediated secretion of proteins required for ß-lactam resistance. Combinations of SpsB inhibitors and ß-lactams may expand the utility of these widely prescribed antibiotics to treat MRSA infections, analogous to ß-lactamase inhibitors which restored the utility of this antibiotic class for the treatment of resistant Gram-negative infections.
Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Compostos de Bifenilo/farmacologia , Depsipeptídeos/farmacologia , Glicopeptídeos/farmacologia , Glicosídeos/farmacologia , Lipopeptídeos/farmacologia , Proteínas de Membrana/antagonistas & inibidores , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Oligopeptídeos/farmacologia , Infecções Estafilocócicas/tratamento farmacológico , beta-Lactamas/farmacologia , Animais , Antibacterianos/isolamento & purificação , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Transporte Biológico , Compostos de Bifenilo/síntese química , Depsipeptídeos/isolamento & purificação , Sinergismo Farmacológico , Quimioterapia Combinada , Feminino , Glicopeptídeos/síntese química , Glicopeptídeos/isolamento & purificação , Glicosídeos/isolamento & purificação , Humanos , Lipopeptídeos/isolamento & purificação , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Staphylococcus aureus Resistente à Meticilina/genética , Staphylococcus aureus Resistente à Meticilina/crescimento & desenvolvimento , Camundongos , Camundongos Endogâmicos BALB C , Testes de Sensibilidade Microbiana , Família Multigênica , Oligopeptídeos/síntese química , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Infecções Estafilocócicas/microbiologia , Resistência beta-Lactâmica/efeitos dos fármacos , Resistência beta-Lactâmica/genética , beta-Lactamases/genética , beta-Lactamases/metabolismoRESUMO
The discovery and SAR of a series of potent renin inhibitors possessing a novel 3,4-diarylpiperidine scaffold are described herein. The resulting compound 38 exhibit low nanomolar plasma renin IC(50), had a clean CYP 3A4 profile and displayed micromolar affinity for the hERG channel. Furthermore, it was found to be efficacious in the double transgenic rat hypertension model and show good to moderate oral bioavailability in two animal species.
Assuntos
Anti-Hipertensivos/química , Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Piperidinas/química , Piperidinas/uso terapêutico , Renina/antagonistas & inibidores , Animais , Anti-Hipertensivos/farmacocinética , Anti-Hipertensivos/farmacologia , Disponibilidade Biológica , Citocromo P-450 CYP3A/metabolismo , Inibidores do Citocromo P-450 CYP3A , Cães , Canais de Potássio Éter-A-Go-Go/metabolismo , Humanos , Piperidinas/farmacocinética , Piperidinas/farmacologia , Ratos , Ratos Sprague-Dawley , Ratos Transgênicos , Renina/metabolismo , Relação Estrutura-AtividadeRESUMO
PKMYT1 is a regulator of CDK1 phosphorylation and is a compelling therapeutic target for the treatment of certain types of DNA damage response cancers due to its established synthetic lethal relationship with CCNE1 amplification. To date, no selective inhibitors have been reported for this kinase that would allow for investigation of the pharmacological role of PKMYT1. To address this need compound 1 was identified as a weak PKMYT1 inhibitor. Introduction of a dimethylphenol increased potency on PKMYT1. These dimethylphenol analogs were found to exist as atropisomers that could be separated and profiled as single enantiomers. Structure-based drug design enabled optimization of cell-based potency. Parallel optimization of ADME properties led to the identification of potent and selective inhibitors of PKMYT1. RP-6306 inhibits CCNE1-amplified tumor cell growth in several preclinical xenograft models. The first-in-class clinical candidate RP-6306 is currently being evaluated in Phase 1 clinical trials for treatment of various solid tumors.
Assuntos
Neoplasias , Proteínas Tirosina Quinases , Linhagem Celular Tumoral , Proliferação de Células , Humanos , Proteínas de Membrana , Neoplasias/patologia , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Proteínas Serina-Treonina QuinasesRESUMO
DNA polymerase theta (Polθ) is an attractive synthetic lethal target for drug discovery, predicted to be efficacious against breast and ovarian cancers harboring BRCA-mutant alleles. Here, we describe our hit-to-lead efforts in search of a selective inhibitor of human Polθ (encoded by POLQ). A high-throughput screening campaign of 350,000 compounds identified an 11 micromolar hit, giving rise to the N2-substituted fused pyrazolo series, which was validated by biophysical methods. Structure-based drug design efforts along with optimization of cellular potency and ADME ultimately led to the identification of RP-6685: a potent, selective, and orally bioavailable Polθ inhibitor that showed in vivo efficacy in an HCT116 BRCA2-/- mouse tumor xenograft model.
Assuntos
DNA Polimerase Dirigida por DNA , Neoplasias Ovarianas , Animais , Replicação do DNA , DNA Polimerase Dirigida por DNA/metabolismo , Desenho de Fármacos , Descoberta de Drogas , Feminino , Humanos , CamundongosRESUMO
The chemoattractant receptor-homologous molecule expressed on T-helper type 2 cells (CRTH2) is a G protein-coupled receptor that has been reported to modulate inflammatory responses in various rodent models of asthma, allergic rhinitis and atopic dermatitis. In this study, we describe the biological and pharmacological properties of {(7R)-7-[[(4-fluorophenyl)sulfonyl](methyl)amino]-6,7,8,9-tetrahydropyrido[1,2-a]indol-10-yl}acetic acid (MK-7246), a novel synthetic CRTH2 antagonist. We show that MK-7246 1) has high affinity for the human, monkey, dog, rat, and mouse CRTH2, 2) interacts with CRTH2 in a reversible manner, 3) exhibits high selectivity over all prostanoid receptors as well as 157 other receptors and enzymes, 4) acts as a full antagonist on recombinant and endogenously expressed CRTH2, 5) demonstrates good oral bioavailability and metabolic stability in various animal species, 6) yields ex vivo blockade of CRTH2 on eosinophils in monkeys and sheep, and 7) significantly blocks antigen-induced late-phase bronchoconstriction and airway hyper-responsiveness in sheep. MK-7246 represents a potent and selective tool to further investigate the in vivo function of CRTH2.
Assuntos
Carbolinas/química , Carbolinas/farmacologia , Receptores Imunológicos/antagonistas & inibidores , Receptores Imunológicos/biossíntese , Receptores de Prostaglandina/antagonistas & inibidores , Receptores de Prostaglandina/biossíntese , Células Th2/metabolismo , Animais , Cães , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/imunologia , Células HEK293 , Humanos , Macaca fascicularis , Camundongos , Inibidores da Agregação Plaquetária/farmacologia , Ligação Proteica/imunologia , Ratos , Receptores Imunológicos/metabolismo , Receptores Imunológicos/fisiologia , Receptores de Prostaglandina/metabolismo , Receptores de Prostaglandina/fisiologia , Ovinos , Especificidade da Espécie , Células Th2/efeitos dos fármacosRESUMO
A new series of indole amide acting as hCRTH2 receptor ligands had been explored and are described herein. Several amide derivatives displaying low nanomolar activity in hCRTH2 binding and whole blood assays were identified. They were found to behave as a full antagonists, exhibiting good selectivity over related prostaglandin receptors. Also, prototypical compounds in this novel series which displayed acceptable CYP profiles and were orally bioavailable in rats were identified.
Assuntos
Amidas/síntese química , Amidas/farmacologia , Indóis/síntese química , Indóis/farmacologia , Receptores de Dopamina D2/agonistas , Amidas/química , Animais , Indóis/química , Concentração Inibidora 50 , Ligantes , Estrutura Molecular , Ligação Proteica/efeitos dos fármacos , RatosRESUMO
A new class of 7-azaindole analogs of MK-7246 as potent and selective CRTH2 antagonists is reported. The SAR leading to the identification of the optimal azaindole regioisomer as well as the pharmacokinetics and off-target activities of the most potent antagonists are disclosed.
Assuntos
Indóis/química , Indóis/farmacologia , Receptores Imunológicos/antagonistas & inibidores , Receptores Imunológicos/metabolismo , Receptores de Prostaglandina/antagonistas & inibidores , Receptores de Prostaglandina/metabolismo , Animais , Carbolinas/química , Humanos , Indóis/farmacocinética , Ratos , Ratos Sprague-Dawley , Relação Estrutura-AtividadeRESUMO
An oral bioavailability issue encountered during the course of lead optimization in the renin program is described herein. The low F(po) of pyridone analogs was shown to be caused by a combination of poor passive permeability and gut efflux transport. Substitution of pyridone ring for a more lipophilic moiety (logD>1.7) had minimal effect on rMdr1a transport but led to increased passive permeability (P(app)>10 × 10(-6) cm/s), which contributed to overwhelm gut transporters and increase rat F(po). LogD and in vitro passive permeability determination were found to be key in guiding SAR and improve oral exposure of renin inhibitors.
Assuntos
Subfamília B de Transportador de Cassetes de Ligação de ATP/antagonistas & inibidores , Permeabilidade da Membrana Celular/efeitos dos fármacos , Piperidinas/farmacologia , Renina/antagonistas & inibidores , Subfamília B de Transportador de Cassetes de Ligação de ATP/deficiência , Subfamília B de Transportador de Cassetes de Ligação de ATP/metabolismo , Administração Oral , Animais , Disponibilidade Biológica , Transporte Biológico/efeitos dos fármacos , Relação Dose-Resposta a Droga , Camundongos , Camundongos Knockout , Estrutura Molecular , Piperidinas/administração & dosagem , Piperidinas/química , Ratos , Renina/metabolismo , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
The incorporation of a carboxylic acid within in a series of 3-amido-4-aryl substituted piperidines (represented by general structure 32) led to the discovery of potent, zwitterionic, renin inhibitors with improved off-target profiles (CYP3A4 time-dependent inhibition and hERG affinity) relative to analogous non-zwitterionic inhibitors of the past (i.e., 3). Strategies to address the oral absorption of these zwitterions are also discussed within.
Assuntos
Inibidores de Proteases/síntese química , Renina/antagonistas & inibidores , Administração Oral , Animais , Domínio Catalítico , Simulação por Computador , Cães , Avaliação Pré-Clínica de Medicamentos , Humanos , Piperidinas/síntese química , Piperidinas/química , Piperidinas/farmacocinética , Inibidores de Proteases/química , Inibidores de Proteases/farmacocinética , Ratos , Ratos Sprague-Dawley , Renina/metabolismo , Relação Estrutura-AtividadeRESUMO
The design and optimization of a novel series of renin inhibitor is described herein. Strategically, by committing the necessary resources to the development of synthetic sequences and scaffolds that were most amenable for late stage structural diversification, even as the focus of the SAR campaign moved from one end of the molecule to another, highly potent renin inhibitors could be rapidly identified and profiled.
Assuntos
Álcoois/síntese química , Anti-Hipertensivos/síntese química , Anti-Hipertensivos/uso terapêutico , Desenho de Fármacos , Hipertensão/tratamento farmacológico , Piperidinas/síntese química , Renina/antagonistas & inibidores , Álcoois/química , Álcoois/uso terapêutico , Animais , Anti-Hipertensivos/química , Estrutura Molecular , Piperidinas/química , Piperidinas/uso terapêutico , Ratos , Renina/química , Relação Estrutura-AtividadeRESUMO
In this manuscript we wish to report the discovery of MK-7246 (4), a potent and selective CRTH2 (DP2) antagonist. SAR studies leading to MK-7246 along with two synthetic sequences enabling the preparation of this novel class of CRTH2 antagonist are reported. Finally, the pharmacokinetic and metabolic profile of MK-7246 is disclosed.
Assuntos
Carbolinas/química , Pneumopatias/tratamento farmacológico , Receptores Imunológicos/antagonistas & inibidores , Receptores de Prostaglandina/antagonistas & inibidores , Animais , Carbolinas/farmacocinética , Carbolinas/uso terapêutico , Humanos , Macaca mulatta , Microssomos Hepáticos/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Imunológicos/metabolismo , Receptores de Prostaglandina/metabolismo , Relação Estrutura-AtividadeRESUMO
The discovery and SAR of a series of potent renin inhibitors possessing a novel biaryl scaffold are described herein. Molecular modeling revealed that the cyclopropylamide spacer present in 1 can be replaced by a simple, substituted aromatic ring such as a toluene in 2. The resulting compounds exhibit subnanomolar renin IC(50) and good oral bioavailability in rats.
Assuntos
Bibenzilas/química , Inibidores Enzimáticos/química , Renina/antagonistas & inibidores , Administração Oral , Amidas/química , Animais , Bibenzilas/síntese química , Bibenzilas/farmacocinética , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/farmacocinética , Ratos , Renina/metabolismo , Relação Estrutura-AtividadeRESUMO
Time-dependent inhibitors of CYPs have the potential to perpetrate drug-drug interactions in the clinical setting. After finding that several leading compounds in a novel series of substituted amino propanamide renin inhibitors inactivated CYP3A4 in an NADPH-dependent and time-dependent manner, a search to identify the cause of this liability was initiated. Extensive SAR revealed that the amide bridge present in compound 1 as a possible culprit. Through the installation of a metabolic soft spot distal to this moiety, potent renin inhibitors with improved CYP profile were identified.
Assuntos
Inibidores do Citocromo P-450 CYP3A , Inibidores Enzimáticos/farmacologia , Propionatos/química , Renina/antagonistas & inibidores , Amidas/química , Citocromo P-450 CYP3A , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacocinética , Humanos , Concentração Inibidora 50 , Microssomos Hepáticos/efeitos dos fármacos , Microssomos Hepáticos/enzimologiaRESUMO
The structure-activity relationship of a novel series of 8-biarylnaphthyridinones acting as type 4 phosphodiesterase (PDE4) inhibitors for the treatment of long-term memory loss and mild cognitive impairment is described herein. The manuscript describes a new paradigm for the development of PDE4 inhibitor targeting CNS indications. This effort led to the discovery of the clinical candidate MK-0952, an intrinsically potent inhibitor (IC(50)=0.6 nM) displaying limited whole blood activity (IC(50)=555 nM). Supporting in vivo results in two preclinical efficacy tests and one test assessing adverse effects are also reported. The comparative profiles of MK-0952 and two other Merck compounds are described to validate the proposed hypothesis.
Assuntos
Transtornos Cognitivos/tratamento farmacológico , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/efeitos dos fármacos , Ciclopropanos/farmacologia , Compostos Heterocíclicos com 2 Anéis/farmacologia , Memória de Longo Prazo/efeitos dos fármacos , Inibidores de Fosfodiesterase/farmacologia , Animais , Ciclopropanos/química , Ciclopropanos/uso terapêutico , Cães , Feminino , Compostos Heterocíclicos com 2 Anéis/química , Compostos Heterocíclicos com 2 Anéis/uso terapêutico , Humanos , Macaca mulatta , Masculino , Inibidores de Fosfodiesterase/química , Inibidores de Fosfodiesterase/uso terapêutico , Ratos , Relação Estrutura-AtividadeRESUMO
The discovery and SAR of a new series of substituted amino propanamide renin inhibitors are herein described. This work has led to the preparation of compounds with in vitro and in vivo profiles suitable for further development. Specifically, challenges pertaining to oral bioavailability, covalent binding and time-dependent CYP 3A4 inhibition were overcome thereby culminating in the identification of compound 50 as an optimized renin inhibitor with good efficacy in the hypertensive double-transgenic rat model.
Assuntos
Anti-Hipertensivos/química , Anti-Hipertensivos/uso terapêutico , Hipertensão/tratamento farmacológico , Renina/antagonistas & inibidores , Renina/metabolismo , Animais , Anti-Hipertensivos/farmacologia , Pressão Sanguínea/efeitos dos fármacos , Cristalografia por Raios X , Cães , Humanos , Modelos Moleculares , Ligação Proteica , Ratos , Ratos Sprague-Dawley , Renina/química , Relação Estrutura-AtividadeRESUMO
Substituted 8-arylquinoline analogs bearing alkyl-linked side chain were identified as potent inhibitors of type 4 phophodiesterase. These compounds address the potential liabilities of the clinical candidate L-454560. The pharmacokinetic profile of the best analogs and the in vivo efficacy in an ovalbumin-induced bronchoconstriction assay in conscious guinea pigs are reported.
Assuntos
Anti-Inflamatórios/química , Inibidores da Fosfodiesterase 4 , Inibidores de Fosfodiesterase/química , Quinolinas/química , Animais , Anti-Inflamatórios/síntese química , Anti-Inflamatórios/farmacocinética , Hidrocarboneto de Aril Hidroxilases/metabolismo , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4/metabolismo , Citocromo P-450 CYP2C9 , Cobaias , Humanos , Leucócitos Mononucleares/metabolismo , Ovalbumina/farmacologia , Inibidores de Fosfodiesterase/síntese química , Inibidores de Fosfodiesterase/farmacocinética , Quinolinas/síntese química , Quinolinas/farmacocinética , Ratos , Saimiri , Relação Estrutura-AtividadeRESUMO
The structure-activity relationship of a novel series of 8-biarylquinolines acting as type 4 phosphodiesterase (PDE4) inhibitors is described herein. Prototypical compounds from this series are potent and non-selective inhibitors of the four distinct PDE4 (IC(50)<10 nM) isozymes (A-D). In a human whole blood in vitro assay, they inhibit (IC(50)<0.5 microM) the LPS-induced release of the cytokine TNF-alpha. Optimized inhibitors were evaluated in vivo for efficacy in an ovalbumin-induced bronchoconstriction model in conscious guinea pigs. Their propensity to produce an emetic response was evaluated by performing pharmacokinetic studies in squirrel monkeys. This work has led to the identification of several compounds with excellent in vitro and in vivo profiles, including a good therapeutic window of efficacy over emesis.
Assuntos
Compostos de Bifenilo/química , Compostos de Bifenilo/farmacologia , Inibidores da Fosfodiesterase 4 , Inibidores de Fosfodiesterase/química , Inibidores de Fosfodiesterase/farmacologia , Quinolinas/química , Quinolinas/farmacologia , Animais , Disponibilidade Biológica , Compostos de Bifenilo/síntese química , Compostos de Bifenilo/farmacocinética , Desenho de Fármacos , Cobaias , Humanos , Inibidores de Fosfodiesterase/síntese química , Inibidores de Fosfodiesterase/farmacocinética , Piridinas/síntese química , Piridinas/química , Piridinas/farmacocinética , Piridinas/farmacologia , Quinolinas/síntese química , Quinolinas/farmacocinética , Estereoisomerismo , Relação Estrutura-AtividadeRESUMO
L-454,560 is a potent phosphodiesterase 4 (PDE4) inhibitor which was identified as a development candidate for the treatment of asthma and chronic obstructive pulmonary disease (COPD). As part of the discovery of this compound, interspecies in vitro metabolism data was generated using liver microsomes and hepatocytes in order to understand the metabolic fate of the compound. In microsomes, metabolism of the 3-methyl-1,2,4-oxadiazole ring was the predominant pathway observed, including ring cleavage. In rat hepatocytes, hydroxylation of the methyl group on the oxadiazole ring and double-bond isomerization were the most abundant metabolites observed. No major species differences were found in terms of microsomal metabolite profiles. The use of LC with UV and MS detection is highlighted, as well as information from tandem mass spectrometry and NMR.
Assuntos
3',5'-AMP Cíclico Fosfodiesterases/antagonistas & inibidores , Hepatócitos/metabolismo , Microssomos Hepáticos/metabolismo , Quinolinas/farmacocinética , Animais , Cromatografia Líquida/métodos , Nucleotídeo Cíclico Fosfodiesterase do Tipo 4 , Cães , Humanos , Macaca mulatta , Espectrometria de Massas/métodos , Camundongos , Ratos , Saimiri , Especificidade da Espécie , Espectrofotometria Ultravioleta/métodosRESUMO
Caspases are cysteine proteases that specifically cleave Asp-Xxx bonds. They are key agents in inflammation and apoptosis and are attractive targets for therapy against inflammation, neurodegeneration, ischemia, and cancer. Many caspase structures are known, but most involve either peptide or protein inhibitors, unattractive candidates for drug development. We present seven crystal structures of inhibited caspase-3 that illustrate several approaches to reducing the peptidyl characteristics of the inhibitors while maintaining their potency and selectivity. The inhibitors reduce the peptidyl nature of inhibitors while preserving binding potency by (1). exploiting a hydrophobic binding site C-terminal to the cleavage site, (2). replacing the negatively charged aspartyl residue at P4 with neutral groups, and (3). using a peptidomimetic 5,6,7-tricyclic system or a pyrazinone at P2-P3. In addition, we have found that two nicotinic acid aldehydes induce a significant conformational change in the S2 and S3 subsites of caspase-3, revealing an unexpected binding mode. These results advance the search for caspase-directed drugs by revealing how unacceptable molecular features can be removed without loss of potency.
Assuntos
Caspases/química , Inibidores Enzimáticos/química , Peptídeos/química , Caspase 3 , Inibidores de Caspase , Cristalografia por Raios X , Compostos Heterocíclicos com 3 Anéis/química , Ligantes , Modelos Moleculares , Mimetismo Molecular , Estrutura Molecular , Niacina/análogos & derivados , Niacina/química , Oligopeptídeos/química , Conformação Proteica , Pirazinas/química , Relação Estrutura-AtividadeRESUMO
BACKGROUND: Silver dressings are a proven method for burn treatment. Current challenges associated with burn treatment include pain management and limited hospital resources. A new silver-coated nylon dressing was used at the Montreal Children's Hospital (Montreal, Quebec) to help reduce traumatic dressing changes and cost. METHODS: Burn victims in a pediatric patient population were followed over two years. Patients were excluded if they were evaluated more than 48 h postburn or if the burn affected less than 5% of the total body surface area. The same burn team admitted and treated all case subjects, and one dressing nurse recorded and monitored all progress throughout the study to ensure standardization. RESULTS: Fifteen patients were included in the study. The average number of dressing changes needed was 4.13, with a median of three changes. The average total body surface area burned was 8%, with a mean of 13.9 days before superficial wounds were re-epithelialized. The average length of in-hospital stay was four days. The cost was $388 less for silver-coated nylon dressings than for silver sulfadiazine cream for seven days of treatment. Silver-coated nylon dressings did not leave any residue or pseudoeschar on the wounds and were easily maintained at home. CONCLUSION: The silver-coated nylon dressings are as effective as other silver dressings used for pediatric burn victims. The dressings are less traumatic, require fewer resources and do not leave wound residue compared with other dressings.