RESUMO
We report the synthesis and bio-pharmacological evaluation of a class of pyrrole derivatives featuring a small appendage fragment (carbaldehyde, oxime, nitrile) on the central core. Compound 1c proved to be extremely effective in vivo, showing an interesting anti-nociceptic profile that is comparable to reference compounds already marketed, hence representing a great stimulus for a further improvement of this class of molecules.
Assuntos
Analgésicos/química , Analgésicos/uso terapêutico , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/uso terapêutico , Pirróis/química , Pirróis/uso terapêutico , Analgésicos/farmacologia , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Linhagem Celular , Inibidores de Ciclo-Oxigenase 2/química , Inibidores de Ciclo-Oxigenase 2/farmacologia , Inibidores de Ciclo-Oxigenase 2/uso terapêutico , Masculino , Camundongos , Dor/tratamento farmacológico , Pirróis/farmacologia , Relação Estrutura-AtividadeRESUMO
The 1,5-diarylpyrrole derivative BM212 was previously shown to be active against multidrug-resistant clinical isolates and Mycobacterium tuberculosis residing within macrophages as well as against Mycobacterium avium and other atypical mycobacteria. To determine its mechanism of action, we identified the cellular target. Spontaneous Mycobacterium smegmatis, Mycobacterium bovis BCG, and M. tuberculosis H37Rv mutants that were resistant to BM212 were isolated. By the screening of genomic libraries and by whole-genome sequencing, we found that all the characterized mutants showed mutations in the mmpL3 gene, allowing us to conclude that resistance to BM212 maps to the MmpL3 protein, a member of the MmpL (mycobacterial membrane protein, large) family. Susceptibility was unaffected by the efflux pump inhibitors reserpine, carbonylcyanide m-chlorophenylhydrazone, and verapamil. Uptake/efflux experiments with [(14)C]BM212 demonstrated that resistance is not driven by the efflux of BM212. Together, these data strongly suggest that the MmpL3 protein is the cellular target of BM212.
Assuntos
Antituberculosos/farmacologia , Genoma Bacteriano , Proteínas de Membrana Transportadoras/genética , Mycobacterium bovis/genética , Mycobacterium smegmatis/genética , Mycobacterium tuberculosis/genética , Piperazinas/farmacologia , Pirróis/farmacologia , Animais , Radioisótopos de Carbono , Carbonil Cianeto m-Clorofenil Hidrazona/análogos & derivados , Carbonil Cianeto m-Clorofenil Hidrazona/farmacologia , Bovinos , Análise Mutacional de DNA , Farmacorresistência Bacteriana Múltipla , Biblioteca Genômica , Humanos , Testes de Sensibilidade Microbiana , Mutação , Infecções por Mycobacterium não Tuberculosas/tratamento farmacológico , Infecções por Mycobacterium não Tuberculosas/microbiologia , Mycobacterium bovis/efeitos dos fármacos , Mycobacterium smegmatis/efeitos dos fármacos , Mycobacterium tuberculosis/efeitos dos fármacos , Reserpina/farmacologia , Verapamil/farmacologiaRESUMO
A hit optimization procedure based on isosteric and bioisosteric replacement of decorating groups at both the N1 and the C5 phenyl rings of 1,5-diarylpyrroles led to identification of 4-((1-(4-fluorophenyl)-2-methyl-5-(4-(methylthio)phenyl)-1H-pyrrol-3-yl)methyl)thiomorpholine that is characterized by a very high activity toward both Mycobacterium tuberculosis 103471 and H37Rv strains (MIC values of 0.125µg/mL), and a safe profile in terms of cytotoxicity (CC(50) of >128µg/mL) and protection index (>1000). Antitubercular activity and protection index of the new compound are comparable to those found for the current antitubercular drugs streptomycin and rifampin.
Assuntos
Antituberculosos/química , Pirróis/química , Rifampina/farmacologia , Estreptomicina/farmacologia , Animais , Antituberculosos/síntese química , Antituberculosos/toxicidade , Chlorocebus aethiops , Mycobacterium tuberculosis/efeitos dos fármacos , Pirróis/síntese química , Pirróis/toxicidade , Relação Estrutura-Atividade , Células VeroRESUMO
Synthesis and biological evaluation of new derivatives of 1,5-bis(4-chlorophenyl)-2-methyl-3-(4-methylpiperazin-1-yl)methyl-1H-pyrrole (BM 212, 16) are reported. Variously substituted phenyl rings with different substitution pattern and lipophilicity were added to the pyrrole nucleus to evaluate their influence on the activity toward Mycobacterium tuberculosis (MTB) and atypical mycobacteria. The most active derivatives showed activity between 0.125-0.5 microg/mL (better than 16 and streptomycin) and protection index (64-256) higher than 16 (4) and similar to isoniazid and streptomycin (128).
Assuntos
Antituberculosos/síntese química , Mycobacterium tuberculosis/efeitos dos fármacos , Micobactérias não Tuberculosas/efeitos dos fármacos , Piperazinas/síntese química , Pirróis/síntese química , Antituberculosos/química , Antituberculosos/farmacologia , Farmacorresistência Bacteriana Múltipla , Testes de Sensibilidade Microbiana , Mycobacterium tuberculosis/isolamento & purificação , Piperazinas/química , Piperazinas/farmacologia , Pirróis/química , Pirróis/farmacologia , Relação Estrutura-AtividadeRESUMO
The assignment of the absolute configuration of novel anti-inflammatory pyrrole derivatives has been accomplished by a combined strategy based on independent physical methods. The key step of our stereochemical characterization approach is the production at mg-scale of enantiomerically pure forms by HPLC on Chiralpak IA stationary phase.
Assuntos
Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Pirróis/química , Pirróis/isolamento & purificação , Dicroísmo Circular , Cristalografia por Raios X , Modelos Moleculares , Conformação Molecular , Estrutura Molecular , Espectrofotometria Ultravioleta , EstereoisomerismoRESUMO
The important role of cyclooxygenase-2 (COX-2) in the pathogenesis of inflammation and side effect limitations of current COX-2 inhibitor drugs illustrates a need for the design of new compounds based on alternative structural templates. We previously reported a set of substituted 1,5-diarylpyrrole derivatives, along with their inhibitory activity toward COX enzymes. Several compounds proved to be highly selective COX-2 inhibitors and their affinity data were rationalized through docking simulations. In this paper, we describe the synthesis of new 1,5-diarylpyrrole derivatives that were assayed for their in vitro inhibitory effects toward COX isozymes. Among them, the ethyl-2-methyl-5-[4-(methylsulfonyl)phenyl]-1-[3-fluorophenyl]-1H-pyrrol-3-acetate (1d), which was the most potent and COX-2 selective compound, also showed a very interesting in vivo anti-inflammatory and analgesic activity, laying the foundations for developing new lead compounds that could be effective agents in the armamentarium for the management of inflammation and pain.
Assuntos
Acetatos/síntese química , Ciclo-Oxigenase 1/metabolismo , Inibidores de Ciclo-Oxigenase 2/síntese química , Ciclo-Oxigenase 2/metabolismo , Pirróis/síntese química , Acetatos/química , Acetatos/farmacologia , Adulto , Animais , Carragenina , Linhagem Celular , Inibidores de Ciclo-Oxigenase 2/química , Inibidores de Ciclo-Oxigenase 2/farmacologia , Dinoprostona/sangue , Edema/induzido quimicamente , Edema/prevenção & controle , Feminino , Humanos , Masculino , Camundongos , Modelos Moleculares , Medição da Dor , Pirróis/química , Pirróis/farmacologia , Radioimunoensaio , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Relação Estrutura-Atividade , Proteínas com Domínio T/sangueRESUMO
On the basis of suggestions derived either from a pharmacophoric model for antitubercular agents or from a structure-activity relationship analysis of many pyrroles previously described by us, we report here the design and synthesis of new analogues of 1,5-(4-chlorophenyl)-2-methyl-3-(4-methylpiperazin-1-yl)methyl-1H-pyrrole (BM212). Various substituents with different substitution patterns were added to both positions 1 and 5 of the pyrrole nucleus to evaluate their influence on the activity toward Mycobacterium tuberculosis (MTB) and atypical mycobacteria. Biological data showed that, although some nontuberculosis mycobacterial strains were found to be sensitive, MIC values were higher than those found toward MTB. The best compound (1-(4-fluorophenyl)-2-methyl-3-(thiomorpholin-4-yl)methyl-5-(4-methylphenyl)-1H-pyrrole, 5) possessed a MIC of 0.4 microg/mL (better than BM212 and streptomycin) and a very high protection index (160), better than BM212, isoniazid, and streptomycin (6, 128, and 128, respectively). Finally, molecular modeling studies were performed to rationalize the activity of the new compounds in terms of both superposition onto a pharmacophoric model for antitubercular compounds and their hydrophobic character.
Assuntos
Antituberculosos/síntese química , Morfolinas/síntese química , Mycobacterium tuberculosis/efeitos dos fármacos , Piperazinas/síntese química , Pirróis/síntese química , Animais , Antituberculosos/farmacologia , Antituberculosos/toxicidade , Chlorocebus aethiops , Testes de Sensibilidade Microbiana , Modelos Moleculares , Morfolinas/farmacologia , Morfolinas/toxicidade , Piperazinas/farmacologia , Piperazinas/toxicidade , Pirróis/farmacologia , Pirróis/toxicidade , Relação Quantitativa Estrutura-Atividade , Células VeroRESUMO
A small set of substituted 1,5-diarylpyrrole-3-acetic and -glyoxylic acid derivatives have been synthesized, and their cyclooxygenase (COX-1 and COX-2) inhibiting properties have been evaluated. Some compounds proved to be highly selective COX-2 inhibitors, and their affinity data have been rationalized through docking simulations in terms of interactions with a crystallographic model of the COX-2 binding site.
Assuntos
Acetatos/síntese química , Inibidores de Ciclo-Oxigenase/síntese química , Prostaglandina-Endoperóxido Sintases/metabolismo , Pirróis/síntese química , Acetatos/química , Acetatos/farmacologia , Animais , Sítios de Ligação , Linhagem Celular , Ciclo-Oxigenase 1 , Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase 2 , Inibidores de Ciclo-Oxigenase/química , Inibidores de Ciclo-Oxigenase/farmacologia , Ésteres/síntese química , Ésteres/química , Ésteres/farmacologia , Proteínas de Membrana , Camundongos , Modelos Moleculares , Prostaglandina-Endoperóxido Sintases/química , Pirróis/química , Pirróis/farmacologiaRESUMO
Herein we report a study aimed at discovering a new class of compounds that are able to inhibit Leishmania donovani cell growth. Evaluation of an in-house library of compounds in a whole-cell screening assay highlighted 4-((1-(4-ethylphenyl)-2-methyl-5-(4-(methylthio)phenyl)-1H-pyrrol-3-yl)methyl)thiomorpholine (compound 1) as the most active. Enzymatic assays on Leishmania infantum trypanothione reductase (LiTR, belonging to the Leishmania donovani complex) shed light on both the interaction with, and the nature of inhibition by, compound 1. A molecular modeling approach based on docking studies and on the estimation of the binding free energy aided our rationalization of the biological data. Moreover, X-ray crystal structure determination of LiTR in complex with compound 1 confirmed all our results: compound 1 binds to the T(SH)2 binding site, lined by hydrophobic residues such as Trp21 and Met113, as well as residues Glu18 and Tyr110. Analysis of the structure of LiTR in complex with trypanothione shows that Glu18 and Tyr110 are also involved in substrate binding, according to a competitive inhibition mechanism.
Assuntos
Antiprotozoários/farmacologia , Azóis/farmacologia , Inibidores Enzimáticos/farmacologia , Leishmania infantum/efeitos dos fármacos , Leishmania infantum/enzimologia , NADH NADPH Oxirredutases/antagonistas & inibidores , Antiprotozoários/síntese química , Antiprotozoários/química , Azóis/síntese química , Azóis/química , Morte Celular/efeitos dos fármacos , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Células KB , Modelos Moleculares , Estrutura Molecular , NADH NADPH Oxirredutases/metabolismo , Testes de Sensibilidade Parasitária , Relação Estrutura-AtividadeRESUMO
1,5-Diphenyl pyrroles were previously identified as a class of compounds endowed with high in vitro efficacy against M. tuberculosis. To improve the physical chemical properties and drug-like parameters of this class of compounds, a medicinal chemistry effort was undertaken. By selecting the optimal substitution patterns for the phenyl rings at N1 and C5 and by replacing the thiomorpholine moiety with a morpholine one, a new series of compounds was produced. The replacement of the sulfur with oxygen gave compounds with lower lipophilicity and improved in vitro microsomal stability. Moreover, since the parent compound of this family has been shown to target MmpL3, mycobacterial mutants resistant to two compounds have been isolated and characterized by sequencing the mmpL3 gene; all the mutants showed point mutations in this gene. The best compound identified to date was progressed to dose-response studies in an acute murine TB infection model. The resulting ED(99) of 49 mg/Kg is within the range of commonly employed tuberculosis drugs, demonstrating the potential of this chemical series. The in vitro and in vivo target validation evidence presented here adds further weight to MmpL3 as a druggable target of interest for anti-tubercular drug discovery.
Assuntos
Antibióticos Antituberculose/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Mycobacterium tuberculosis/efeitos dos fármacos , Piperazinas/farmacologia , Pirróis/farmacologia , Tuberculose/metabolismo , Animais , Antibióticos Antituberculose/química , Antibióticos Antituberculose/toxicidade , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Linhagem Celular , Feminino , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Microssomos/metabolismo , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/metabolismo , Piperazinas/química , Piperazinas/toxicidade , Pirróis/química , Pirróis/toxicidade , Tuberculose/tratamento farmacológicoRESUMO
The development of a novel class of pharmacodynamic hybrids that inhibits COX-2 isoform is reported. These molecules display enhanced nitric oxide releasing properties due to the presence of an ionisable moiety. The in vivo analgesic/anti-inflammatory activity was maintained in relation to the parent compounds.
Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Constrição Patológica/tratamento farmacológico , Ciclo-Oxigenase 2/metabolismo , Inibidores Enzimáticos/química , Inibidores Enzimáticos/farmacologia , Óxido Nítrico/metabolismo , Ácido Acético , Animais , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacocinética , Carragenina/antagonistas & inibidores , Carragenina/farmacologia , Constrição Patológica/induzido quimicamente , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/farmacocinética , Isoenzimas/antagonistas & inibidores , Isoenzimas/metabolismo , Masculino , Camundongos , Estrutura Molecular , Músculo Liso Vascular/química , Músculo Liso Vascular/efeitos dos fármacos , Músculo Liso Vascular/metabolismo , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Solubilidade , Relação Estrutura-AtividadeRESUMO
Tuberculosis (TB) represents a never-ending challenge toward which research efforts are needed. Drug resistance is the key problem that scientists in the field need to fight. The development of new drugs endowed with novel modes of action against different biological targets is of extreme importance; these new agents should also exhibit lower toxicity compared with the anti-TB drugs currently available. Furthermore, new drugs should be inexpensive since most of the TB-infected population lives in developing nations. In the last few years, numerous researchers have focused their attention on TB, leading to the discovery of some interesting compounds. Among these, the pyrrole-derived compounds we developed can be considered very promising antimycobacterial agents. Aided by molecular modeling studies, we synthesized numerous compounds characterized by the same 1,5-diarylpyrrole scaffold and elucidated very interesting antitubercular/antimycobacterial properties. Some compounds identified are extremely promising and represent a step towards the design of novel lead structures in the fight against TB. Our efforts to this end are reviewed here.
Assuntos
Antituberculosos/uso terapêutico , Mycobacterium tuberculosis/efeitos dos fármacos , Pirróis/uso terapêutico , Tuberculose/tratamento farmacológico , Animais , Antituberculosos/síntese química , Antituberculosos/química , Antituberculosos/farmacologia , Desenho de Fármacos , Humanos , Mycobacterium tuberculosis/crescimento & desenvolvimento , Mycobacterium tuberculosis/metabolismo , Pirróis/síntese química , Pirróis/química , Pirróis/farmacologia , Relação Estrutura-Atividade , Tuberculose/metabolismo , Tuberculose/patologiaRESUMO
The design of compounds that are able to inhibit cyclooxygenase (COX) and to release nitric oxide (NO) should give rise to drugs endowed with an overall safer profile for the gastrointestinal and cardiovascular systems. Herein we report a new class of pyrrole-derived nitrooxy esters (11a-j), cyclooxygenase-2 (COX-2) selective inhibitors endowed with NO releasing properties, with the goal of generating new molecules able to both strongly inhibit this isoform and reduce the related adverse side effects. Taking into account the metabolic conversion of nitrooxy esters into corresponding alcohols, we also studied derivatives 12a-j. All compounds proved to be very potent and selective COX-2 inhibitors; nitrooxy derivatives displayed interesting ex vivo NO-dependent vasorelaxing properties. Compounds 11c, 11d, 12c, and 12d were selected for further in vivo studies that highlited good anti-inflammatory and antinociceptive activities. Finally, two selected compounds (11c and 12c) tested in human whole blood (HWB) assay proved to be preferential inhibitors of COX-2.
Assuntos
Acetatos/síntese química , Inibidores de Ciclo-Oxigenase 2/síntese química , Doadores de Óxido Nítrico/síntese química , Pirróis/síntese química , Acetatos/química , Acetatos/farmacologia , Animais , Linhagem Celular , Constrição Patológica/induzido quimicamente , Constrição Patológica/prevenção & controle , Inibidores de Ciclo-Oxigenase 2/química , Inibidores de Ciclo-Oxigenase 2/farmacologia , Edema/induzido quimicamente , Edema/tratamento farmacológico , Ésteres , Humanos , Hiperalgesia/induzido quimicamente , Hiperalgesia/prevenção & controle , Técnicas In Vitro , Isoenzimas/antagonistas & inibidores , Macrófagos/efeitos dos fármacos , Macrófagos/enzimologia , Masculino , Camundongos , Modelos Moleculares , Doadores de Óxido Nítrico/química , Doadores de Óxido Nítrico/farmacologia , Pirróis/química , Pirróis/farmacologia , Ratos , Ratos Sprague-Dawley , Ratos Wistar , Relação Estrutura-Atividade , Vasodilatadores/síntese química , Vasodilatadores/química , Vasodilatadores/farmacologiaRESUMO
Our work on antitubercular agents led to the identification of BM 212 as a lead compound among a series of pyrrole derivatives with good in vitro activity against mycobacteria and candidae. Further studies led us to synthesize additional pyrroles bearing the thiomorpholinomethyl moiety and different aryl substituents at N1 and C5. Some of them revealed very active, prompting us to design the new pyrrole derivatives 5-20 in the hope of increasing the activity and better understanding the influence of ortho halogens on the antimycobacterial activity. Microbiological data showed interesting in vitro activity toward Mycobacterium tuberculosis and atypical mycobacteria.
Assuntos
Antituberculosos/farmacologia , Piperazinas/farmacologia , Pirróis/farmacologia , Antituberculosos/química , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Piperazinas/química , Pirróis/químicaRESUMO
We have identified BM212 as a lead compound among a series of pyrrole derivatives with good in vitro activity against mycobacteria and candidae. First studies led us to synthesize some pyrrole compounds in which the thiomorpholine fragment was present. Some compounds revealed very active and these findings prompted us to prepare new pyrrole derivatives 2-15 in the hope of increasing the activity. The microbiological data showed interesting in vitro activity against Mycobacterium tuberculosis and atypical mycobacteria.