RESUMO
The imidazopyridines are a promising new class of antitubercular agents with potent activity in vitro and in vivo We isolated mutants of Mycobacterium tuberculosis resistant to a representative imidazopyridine; the mutants had large shifts (>20-fold) in MIC. Whole-genome sequencing revealed mutations in Rv1339, a hypothetical protein of unknown function. We isolated mutants resistant to three further compounds from the series; resistant mutants isolated from two of the compounds had single nucleotide polymorphisms in Rv1339 and resistant mutants isolated from the third compound had single nucleotide polymorphisms in QcrB, the proposed target for the series. All the strains were resistant to two compounds, regardless of the mutation, and a strain carrying the QcrB T313I mutation was resistant to all of the imidazopyridine derivatives tested, confirming cross-resistance. By monitoring pH homeostasis and ATP generation, we confirmed that compounds from the series were targeting QcrB; imidazopyridines disrupted pH homeostasis and depleted ATP, providing further evidence of an effect on the electron transport chain. A representative compound was bacteriostatic against replicating bacteria, consistent with a mode of action against QcrB. The series had a narrow inhibitory spectrum, with no activity against other bacterial species. No synergy or antagonism was seen with other antituberculosis drugs under development. In conclusion, our data support the hypothesis that the imidazopyridine series functions by reducing ATP generation via inhibition of QcrB.
Assuntos
Trifosfato de Adenosina/metabolismo , Antituberculosos/farmacologia , Imidazóis/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Piridinas/farmacologia , Complexo IV da Cadeia de Transporte de Elétrons/genética , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Testes de Sensibilidade Microbiana , Mutação/genética , Sequenciamento Completo do GenomaRESUMO
We identified a di-substituted triazolopyrimidine with anti-tubercular activity against Mycobacterium tuberculosis. Three segments of the scaffold were examined rationally to establish a structure-activity relationship with the goal of improving potency and maintaining good physicochemical properties. A number of compounds displayed sub-micromolar activity against Mycobacterium tuberculosis with no cytotoxicity against eukaryotic cells. Non-substituted aromatic rings at C5 and a two-carbon chain connecting a terminal aromatic at C7 were preferred features; the presence of NH at C7 and a lack of substituent at C2 were essential for potency. We identified compounds with acceptable metabolic stability in rodent and human liver microsomes. Our findings suggest that the easily-synthesized triazolopyrimidines are a promising class of potent anti-tubercular agents and warrant further investigation in our search for new drugs to fight tuberculosis.
Assuntos
Antituberculosos/síntese química , Antituberculosos/farmacologia , Pirimidinas/síntese química , Pirimidinas/farmacologia , Triazóis/química , Animais , Antituberculosos/química , Humanos , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/efeitos dos fármacos , Pirimidinas/química , Relação Estrutura-AtividadeRESUMO
The 2,4-diaminoquinazoline class of compounds has previously been identified as an effective inhibitor of Mycobacterium tuberculosis growth. We conducted an extensive evaluation of the series for its potential as a lead candidate for tuberculosis drug discovery. Three segments of the representative molecule N-(4-fluorobenzyl)-2-(piperidin-1-yl)quinazolin-4-amine were examined systematically to explore structure-activity relationships influencing potency. We determined that the benzylic amine at the 4-position, the piperidine at 2-position and the N-1 (but not N-3) are key activity determinants. The 3-deaza analog retained similar activity to the parent molecule. Biological activity was not dependent on iron or carbon source availability. We demonstrated through pharmacokinetic studies in rats that good in vivo compound exposure is achievable. A representative compound demonstrated bactericidal activity against both replicating and non-replicating M. tuberculosis. We isolated and sequenced M. tuberculosis mutants resistant to this compound and observed mutations in Rv3161c, a gene predicted to encode a dioxygenase, suggesting that the compound may act as a pro-drug.
Assuntos
Antituberculosos/síntese química , Antituberculosos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Quinazolinas/química , Quinazolinas/farmacologia , Animais , Antituberculosos/química , Antituberculosos/farmacocinética , Farmacorresistência Bacteriana/efeitos dos fármacos , Meia-Vida , Testes de Sensibilidade Microbiana , Quinazolinas/síntese química , Quinazolinas/farmacocinética , Ratos , Ratos Sprague-Dawley , Relação Estrutura-AtividadeRESUMO
Rising antimicrobial resistance challenges our ability to combat bacterial infections. The problem is acute for tuberculosis (TB), the leading cause of death from infection before COVID-19. Here, we developed a framework for multiple pharmaceutical companies to share proprietary information and compounds with multiple laboratories in the academic and government sectors for a broad examination of the ability of ß-lactams to kill Mycobacterium tuberculosis (Mtb). In the TB Drug Accelerator (TBDA), a consortium organized by the Bill & Melinda Gates Foundation, individual pharmaceutical companies collaborate with academic screening laboratories. We developed a higher order consortium within the TBDA in which four pharmaceutical companies (GlaxoSmithKline, Sanofi, MSD, and Lilly) collectively collaborated with screeners at Weill Cornell Medicine, the Infectious Disease Research Institute (IDRI), and the National Institute of Allergy and Infectious Diseases (NIAID), pharmacologists at Rutgers University, and medicinal chemists at the University of North Carolina to screen â¼8900 ß-lactams, predominantly cephalosporins, and characterize active compounds. In a striking contrast to historical expectation, 18% of ß-lactams screened were active against Mtb, many without a ß-lactamase inhibitor. One potent cephaloporin was active in Mtb-infected mice. The steps outlined here can serve as a blueprint for multiparty, intra- and intersector collaboration in the development of anti-infective agents.
Assuntos
COVID-19 , Mycobacterium tuberculosis , Animais , Indústria Farmacêutica , Camundongos , SARS-CoV-2 , Universidades , beta-Lactamas/farmacologiaRESUMO
The identification and development of new anti-tubercular agents are a priority research area. We identified the trifluoromethyl pyrimidinone series of compounds in a whole-cell screen against Mycobacterium tuberculosis. Fifteen primary hits had minimum inhibitory concentrations (MICs) with good potency IC90 is the concentration at which M. tuberculosis growth is inhibited by 90% (IC90 < 5 µM). We conducted a structure-activity relationship investigation for this series. We designed and synthesized an additional 44 molecules and tested all analogs for activity against M. tuberculosis and cytotoxicity against the HepG2 cell line. Substitution at the 5-position of the pyrimidinone with a wide range of groups, including branched and straight chain alkyl and benzyl groups, resulted in active molecules. Trifluoromethyl was the preferred group at the 6-position, but phenyl and benzyl groups were tolerated. The 2-pyridyl group was required for activity; substitution on the 5-position of the pyridyl ring was tolerated but not on the 6-position. Active molecules from the series demonstrated low selectivity, with cytotoxicity against eukaryotic cells being an issue. However, there were active and non-cytotoxic molecules; the most promising molecule had an MIC (IC90) of 4.9 µM with no cytotoxicity (IC50 > 100 µM). The series was inactive against Gram-negative bacteria but showed good activity against Gram-positive bacteria and yeast. A representative molecule from this series showed rapid concentration-dependent bactericidal activity against replicating M. tuberculosis bacilli with ~4 log kill in <7 days. Overall the biological properties were promising, if cytotoxicity could be reduced. There is scope for further medicinal chemistry optimization to improve the properties without major change in structural features.
RESUMO
With the emergence of multi-drug-resistant strains of Mycobacterium tuberculosis, there is a pressing need for new oral drugs with novel mechanisms of action. A number of scaffolds with potent anti-tubercular in vitro activity have been identified from phenotypic screening that appear to target MmpL3. However, the scaffolds are typically lipophilic, which facilitates partitioning into hydrophobic membranes, and several contain basic amine groups. Highly lipophilic basic amines are typically cytotoxic against mammalian cell lines and have associated off-target risks, such as inhibition of human ether-à-go-go related gene (hERG) and IKr potassium current modulation. The spirocycle compound 3 was reported to target MmpL3 and displayed promising efficacy in a murine model of acute tuberculosis (TB) infection. However, this highly lipophilic monobasic amine was cytotoxic and inhibited the hERG ion channel. Herein, the related spirocycles (1-2) are described, which were identified following phenotypic screening of the Eli Lilly corporate library against M. tuberculosis. The novel N-alkylated pyrazole portion offered improved physicochemical properties, and optimization led to identification of a zwitterion series, exemplified by lead 29, with decreased HepG2 cytotoxicity as well as limited hERG ion channel inhibition. Strains with mutations in MmpL3 were resistant to 29, and under replicating conditions, 29 demonstrated bactericidal activity against M. tuberculosis. Unfortunately, compound 29 had no efficacy in an acute model of TB infection; this was most likely due to the in vivo exposure remaining above the minimal inhibitory concentration for only a limited time.
RESUMO
To find new inhibitors of Mycobacterium tuberculosis that have novel mechanisms of action, we miniaturized a high throughput screen to identify compounds that disrupt pH homeostasis. We adapted and validated a 384-well format assay to determine intrabacterial pH using a ratiometric green fluorescent protein. We screened 89000 small molecules under nonreplicating conditions and confirmed 556 hits that reduced intrabacterial pH (below pH 6.5). We selected five compounds that disrupt intrabacterial pH homeostasis and also showed some activity against nonreplicating bacteria in a 4-stress model, but with no (or greatly reduced) activity against replicating bacteria. The compounds selected were two benzamide sulfonamides, a benzothiadiazole, a bissulfone, and a thiadiazole, none of which are known antibacterial agents. All of these five compounds demonstrated bactericidal activity against nonreplicating bacteria in buffer. Four of the five compounds demonstrated increased activity under low pH conditions. None of the five compounds acted as ionophores or as general disrupters of membrane potential. These compounds are useful starting points for work to elucidate their mechanism of action and their utility for drug discovery.
Assuntos
Antituberculosos/isolamento & purificação , Antituberculosos/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Descoberta de Drogas , Proteínas de Fluorescência Verde , Ensaios de Triagem em Larga Escala , Homeostase , Concentração de Íons de Hidrogênio , Testes de Sensibilidade MicrobianaRESUMO
We describe a novel corticotropin-releasing factor receptor 1 (CRF1) antagonist with advantageous properties for clinical development, and its in vivo activity in preclinical alcoholism models. 3-(4-Chloro-2-morpholin-4-yl-thiazol-5-yl)-8-(1-ethylpropyl)-2,6-dimethyl-imidazo[1,2-b]pyridazine (MTIP) inhibited 125I-sauvagine binding to rat pituitary membranes and cloned human CRF1 with subnanomolar affinities, with no detectable activity at the CRF2 receptor or other common drug targets. After oral administration to rats, MTIP inhibited 125I-sauvagine binding to rat cerebellar membranes ex vivo with an ED50 of approximately 1.3 mg/kg and an oral bioavailability of 91.1%. Compared with R121919 (2,5-dimethyl-3-(6-dimethyl-4-methylpyridin-3-yl)-7-dipropylamino-pyrazolo[1,5-a]pyrimidine) and CP154526 (N-butyl-N-ethyl-4,9-dimethyl-7-(2,4,6-trimethylphenyl)-3,5,7-triazabicyclo[4.3.0]nona-2,4,8,10-tetraen-2-amine), MTIP had a markedly reduced volume of distribution and clearance. Neither open-field activity nor baseline exploration of an elevated plus-maze was affected by MTIP (1-10 mg/kg). In contrast, MTIP dose-dependently reversed anxiogenic effects of withdrawal from a 3 g/kg alcohol dose. Similarly, MTIP blocked excessive alcohol self-administration in Wistar rats with a history of dependence, and in a genetic model of high alcohol preference, the msP rat, at doses that had no effect in nondependent Wistar rats. Also, MTIP blocked reinstatement of stress-induced alcohol seeking both in postdependent and in genetically selected msP animals, again at doses that were ineffective in nondependent Wistar rats. Based on these findings, MTIP is a promising candidate for treatment of alcohol dependence.
Assuntos
Alcoolismo/tratamento farmacológico , Encéfalo/metabolismo , Piridazinas/farmacocinética , Piridazinas/uso terapêutico , Receptores de Hormônio Liberador da Corticotropina/antagonistas & inibidores , Tiazóis/farmacocinética , Tiazóis/uso terapêutico , Administração Oral , Consumo de Bebidas Alcoólicas/psicologia , Alcoolismo/genética , Alcoolismo/psicologia , Proteínas de Anfíbios , Animais , Ansiedade/psicologia , Comportamento Animal/efeitos dos fármacos , Cerebelo/efeitos dos fármacos , Cerebelo/metabolismo , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Etanol/administração & dosagem , Masculino , Hormônios Peptídicos , Peptídeos/antagonistas & inibidores , Peptídeos/metabolismo , Hipófise/efeitos dos fármacos , Hipófise/metabolismo , Piridazinas/administração & dosagem , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Autoadministração , Estresse Fisiológico/psicologia , Síndrome de Abstinência a Substâncias/psicologia , Tiazóis/administração & dosagemRESUMO
The phenoxy alkyl benzimidazoles (PABs) have good antitubercular activity. We expanded our structure-activity relationship studies to determine the core components of PABs required for activity. The most potent compounds had minimum inhibitory concentrations against Mycobacterium tuberculosis in the low nanomolar range with very little cytotoxicity against eukaryotic cells as well as activity against intracellular bacteria. We isolated resistant mutants against PAB compounds, which had mutations in either Rv1339, of unknown function, or qcrB, a component of the cytochrome bc1 oxidase of the electron transport chain. QcrB mutant strains were resistant to all PAB compounds, whereas Rv1339 mutant strains were only resistant to a subset, suggesting that QcrB is the target. The discovery of the target for PAB compounds will allow for the improved design of novel compounds to target intracellular M. tuberculosis.
Assuntos
Benzimidazóis/farmacologia , Complexo III da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Mycobacterium tuberculosis/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Relação Estrutura-AtividadeRESUMO
Nitazoxanide has antiparasitic and antibiotic activities including activity against Mycobacterium tuberculosis. We prepared and evaluated a set of its analogues to determine the structure-activity relationship, and identified several amide- and urea-based analogues with low micromolar activity against M. tuberculosis in vitro. Pharmacokinetics in the rat suggested a path forward to obtain bioavailable compounds. The series had a good microbiological profile with bactericidal activity in vitro against replicating and nonreplicating M. tuberculosis. Analogues had limited activity against other Gram-positive bacteria but no activity against Gram-negative bacteria. Our studies identified the key liability in this series as cytotoxicity. Future work concentrating on identifying the target(s) could assist in removing activity against eukaryotic cells.
RESUMO
The 2-aminothiazole series has anti-bacterial activity against the important global pathogen Mycobacterium tuberculosis. We explored the nature of the activity by designing and synthesizing a large number of analogs and testing these for activity against M. tuberculosis, as well as eukaryotic cells. We determined that the C-2 position of the thiazole can accommodate a range of lipophilic substitutions, while both the C-4 position and the thiazole core are sensitive to change. The series has good activity against M. tuberculosis growth with sub-micromolar minimum inhibitory concentrations being achieved. A representative analog was selective for mycobacterial species over other bacteria and was rapidly bactericidal against replicating M. tuberculosis. The mode of action does not appear to involve iron chelation. We conclude that this series has potential for further development as novel anti-tubercular agents.
Assuntos
Antituberculosos/síntese química , Antituberculosos/farmacologia , Tiazóis/síntese química , Tiazóis/farmacologia , Animais , Antituberculosos/química , Quelantes de Ferro/farmacologia , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/efeitos dos fármacos , Relação Estrutura-Atividade , Tiazóis/química , Células VeroRESUMO
We conducted an evaluation of the phenoxyalkylbenzimidazole series based on the exemplar 2-ethyl-1-(3-phenoxypropyl)-1H-benzo[d]imidazole for its antitubercular activity. Four segments of the molecule were examined systematically to define a structure-activity relationship with respect to biological activity. Compounds had submicromolar activity against Mycobacterium tuberculosis; the most potent compound had a minimum inhibitory concentration (MIC) of 52 nM and was not cytotoxic against eukaryotic cells (selectivity index = 523). Compounds were selective for M. tuberculosis over other bacterial species, including the closely related Mycobacterium smegmatis. Compounds had a bacteriostatic effect against aerobically grown, replicating M. tuberculosis, but were bactericidal against nonreplicating bacteria. Representative compounds had moderate to high permeability in MDCK cells, but were rapidly metabolized in rodents and human liver microsomes, suggesting the possibility of rapid in vivo hepatic clearance mediated by oxidative metabolism. These results indicate that the readily synthesized phenoxyalkylbenzimidazoles are a promising class of potent and selective antitubercular agents, if the metabolic liability can be solved.
Assuntos
Antituberculosos/química , Benzimidazóis/química , Animais , Antituberculosos/síntese química , Antituberculosos/farmacologia , Benzimidazóis/síntese química , Benzimidazóis/farmacologia , Chlorocebus aethiops , Simulação por Computador , Cães , Humanos , Células Madin Darby de Rim Canino , Camundongos , Testes de Sensibilidade Microbiana , Microssomos Hepáticos/metabolismo , Mycobacterium tuberculosis/efeitos dos fármacos , Permeabilidade , Ratos , Relação Estrutura-Atividade , Células VeroRESUMO
The RAS-RAF-MEK-MAPK cascade is an essential signaling pathway, with activation typically mediated through cell surface receptors. The kinase inhibitors vemurafenib and dabrafenib, which target oncogenic BRAF V600E, have shown significant clinical efficacy in melanoma patients harboring this mutation. Because of paradoxical pathway activation, both agents were demonstrated to promote growth and metastasis of tumor cells with RAS mutations in preclinical models and are contraindicated for treatment of cancer patients with BRAF WT background, including patients with KRAS or NRAS mutations. In order to eliminate the issues associated with paradoxical MAPK pathway activation and to provide therapeutic benefit to patients with RAS mutant cancers, we sought to identify a compound not only active against BRAF V600E but also wild type BRAF and CRAF. On the basis of its superior in vitro and in vivo profile, compound 13 was selected for further development and is currently being evaluated in phase I clinical studies.
Assuntos
Antineoplásicos/química , Antineoplásicos/farmacologia , Compostos de Fenilureia/química , Compostos de Fenilureia/farmacologia , Proteínas Proto-Oncogênicas B-raf/genética , Pirimidinas/química , Pirimidinas/farmacologia , Proteínas ras/metabolismo , Animais , Antineoplásicos/síntese química , Antineoplásicos/farmacocinética , Disponibilidade Biológica , Linhagem Celular Tumoral/efeitos dos fármacos , Técnicas de Química Sintética , Cães , Feminino , Meia-Vida , Humanos , Masculino , Camundongos Nus , Terapia de Alvo Molecular , Mutação , Compostos de Fenilureia/síntese química , Compostos de Fenilureia/farmacocinética , Proteínas Proto-Oncogênicas B-raf/antagonistas & inibidores , Proteínas Proto-Oncogênicas B-raf/metabolismo , Proteínas Proto-Oncogênicas c-raf/metabolismo , Pirimidinas/síntese química , Pirimidinas/farmacocinética , Ratos Sprague-Dawley , Relação Estrutura-Atividade , Ensaios Antitumorais Modelo de Xenoenxerto , Proteínas ras/genéticaRESUMO
An increasingly competitive pharmaceutical market demands improvement in the efficiency and probability of drug candidate discovery. Usually these new drug candidates are targeted for oral administration, so a detailed understanding of the molecular-level properties that relate to optimal pharmacokinetics is a critical step toward improving the probability of selecting successful clinical candidates. Although the characteristics of druglike molecules have been previously discussed in the literature, the importance of this topic sustains a continued interest for additional perspective and further detailed statistical analyses. In this contribution, we approach the analysis from the perspective of profiling distinguishing features of orally administered drugs. We have compiled both structural and route-administration information for a total of 1729 marketed drugs to provide a solid basis for developing a new perspective on the characteristics of over 1000 orally administered drugs. The molecular properties and most commonly occurring structural elements are statistically analyzed to capture the differences between routes of administration, as well as between marketed drugs and SAR or clinical compounds. We find that, with respect to other routes of administration, oral drugs tend to be lighter and have fewer H-bond donors, acceptors, and rotatable bonds than drugs with other routes of administration. These differences are particularly pronounced when comparing the mean values for oral vs injectable drugs. We also demonstrate that the mean property values for oral drugs do not vary substantially with respect to launch date, suggesting that the range of acceptable oral properties is independent of synthetic complexity or targeted receptor. Finally, we note that, while these properties are descriptive of each class, they are not necessarily predictive of what class any particular drug will reside in, since there is significant overlap in the acceptable ranges found for each drug class.
Assuntos
Preparações Farmacêuticas/química , Administração Oral , Fenômenos Químicos , Físico-Química , Injeções , Estrutura Molecular , Preparações Farmacêuticas/administração & dosagem , Estatística como Assunto , Relação Estrutura-AtividadeRESUMO
Two closely related diaryl acylsulfonamides were recently reported as potent antitumor agents against a broad spectrum of human tumor xenografts (colon, lung, breast, ovary, and prostate) in nude mice. Especially intriguing was their activity against colorectal cancer xenografts. In this paper, rapid parallel synthesis along with traditional medicinal chemistry techniques were used to quickly delineate the structure-activity relationships of the substitution patterns in both phenyl rings of the acylsufonamide anti-proliferative scaffold. Although the molecular target of the compounds remains unclear, we determined that the vascular endothelial growth factor-dependent human umbilical vein endothelial cells assay in combination with a soft agar disk diffusion assay allowed for optimization of potency in the series. The pharmacokinetic properties and in vivo activity in an HCT116 xenograft model are reported for representative compounds.
Assuntos
Antineoplásicos/síntese química , Sulfonamidas/síntese química , Animais , Antineoplásicos/química , Antineoplásicos/farmacologia , Divisão Celular/efeitos dos fármacos , Linhagem Celular , Ensaios de Seleção de Medicamentos Antitumorais , Endotélio Vascular/citologia , Endotélio Vascular/efeitos dos fármacos , Feminino , Meia-Vida , Humanos , Técnicas In Vitro , Camundongos , Camundongos Nus , Relação Quantitativa Estrutura-Atividade , Ratos , Ratos Endogâmicos F344 , Sulfonamidas/química , Sulfonamidas/farmacologia , Transplante Heterólogo , Veias Umbilicais/citologia , Fator A de Crescimento do Endotélio Vascular/farmacologia , Fator A de Crescimento do Endotélio Vascular/fisiologiaRESUMO
The three peptides pancreatic polypeptide (PP), peptide YY (PYY), and neuropeptide Y (NPY) share a similar structure known as the PP-fold. There are four known human G-protein coupled receptors for the PP-fold peptides, namely Y1, Y2, Y4, and Y5, each of them being able to bind at least two of the three endogenous ligands. All three peptides are found in the circulation acting as hormones. Although NPY is only released from neurons, PYY and PP are primarily found in endocrine cells in the gut, where they exert such effects as inhibition of gall bladder secretion, gut motility, and pancreatic secretion. However, when PYY is administered in an experimental setting to animals, cloned receptors, or tissue preparations, it can mimic the effects of NPY in essentially all studies, making it difficult to study the effects of PP-fold peptides and to delineate what receptor and peptide accounts for a particular effect. Initial studies with transgenic animals confirmed the well-established action of NPY on metabolism, food-intake, vascular systems, memory, mood, neuronal excitability, and reproduction. More recently, using transgenic techniques and novel antagonists for the Y1, Y2, and Y5 receptors, NPY has been found to be a key player in the regulation of ethanol consumption and neuronal development.
Assuntos
Neuropeptídeo Y/metabolismo , Polipeptídeo Pancreático/metabolismo , Peptídeo YY/metabolismo , Receptores de Peptídeos/metabolismo , Sequência de Aminoácidos , Animais , Camundongos , Camundongos Knockout , Dados de Sequência Molecular , Neuropeptídeo Y/genética , Neuropeptídeo Y/fisiologia , Polipeptídeo Pancreático/genética , Polipeptídeo Pancreático/fisiologia , Peptídeo YY/genética , Peptídeo YY/fisiologia , Ratos , Receptores de Peptídeos/químicaRESUMO
The enzyme pantothenate synthetase, PanC, is an attractive drug target in Mycobacterium tuberculosis. It is essential for the in vitro growth of M. tuberculosis and for survival of the bacteria in the mouse model of infection. PanC is absent from mammals. We developed an enzyme-based assay to identify inhibitors of PanC, optimized it for high-throughput screening, and tested a large and diverse library of compounds for activity. Two compounds belonging to the same chemical class of 3-biphenyl-4- cyanopyrrole-2-carboxylic acids had activity against the purified recombinant protein, and also inhibited growth of live M. tuberculosis in manner consistent with PanC inhibition. Thus we have identified a new class of PanC inhibitors with whole cell activity that can be further developed.
Assuntos
Proteínas de Bactérias/antagonistas & inibidores , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Mycobacterium tuberculosis/enzimologia , Peptídeo Sintases/antagonistas & inibidores , Tuberculose/tratamento farmacológico , Animais , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Chlorocebus aethiops , Modelos Animais de Doenças , Avaliação Pré-Clínica de Medicamentos , Camundongos , Viabilidade Microbiana/efeitos dos fármacos , Peptídeo Sintases/química , Peptídeo Sintases/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Tuberculose/enzimologia , Células VeroRESUMO
A set of fourteen imidazo[1,2-a]pyridine-3-carboxamides was synthesized and screened against Mycobacterium tuberculosis H37Rv. The minimum inhibitory concentrations of twelve of these agents were ≤ 1 µM against replicating bacteria and five compounds (9, 12, 16, 17 and 18) had MIC values ≤ 0.006 µM. Compounds 13 and 18 were screened against a panel of MDR and XDR drug resistant clinical Mtb strains with the potency of 18 surpassing that of clinical candidate PA-824 by nearly 10 fold. The in vivo pharmacokinetics of compounds 13 and 18 were evaluated in male mice by oral (PO) and intravenous (IV) routes. These results indicate that readily synthesized imidazo[1,2-a]pyridine-3-carboxamides are an exciting new class of potent, selective anti-TB agents that merit additional development opportunities.
RESUMO
A set of nine 2,7-dimethylimidazo[1,2-a]pyridine-3-carboxamides and one 2,6-dimethylimidazo[1,2-a]pyrimidine-3-carboxamide were synthesized. The compounds were evaluated for their in vitro anti-tuberculosis activity versus replicating, non-replicating, multi- and extensive drug resistant Mtb strains. The MIC(90) values of seven of these agents were ≤ 1 µM against the various tuberculosis strains tested. A representative compound of this class (1) was screened against seven non-tubercular strains as well as other non-mycobacteria organisms and demonstrated remarkable microbe selectivity. A transcriptional profiling experiment of Mtb treated with compound 1 was performed to give a preliminary indication of the mode of action. Lastly, the in vivo ADME properties of compounds 1, 3, 4, and 6 were assessed. The 2,7-dimethylimidazo[1,2-a]pyridine-3-carboxamides are a drug-like and synthetically accessible class of anti-TB agents that have excellent selective potency against multi- and extensive drug resistant TB and encouraging pharmacokinetics.