RESUMEN
Protein lysine methyltransferases (PKMTs) regulate diverse physiological processes including transcription and the maintenance of genomic integrity. Genetic studies suggest that the PKMTs SUV420H1 and SUV420H2 facilitate proficient nonhomologous end-joining (NHEJ)-directed DNA repair by catalyzing the di- and trimethylation (me2 and me3, respectively) of lysine 20 on histone 4 (H4K20). Here we report the identification of A-196, a potent and selective inhibitor of SUV420H1 and SUV420H2. Biochemical and co-crystallization analyses demonstrate that A-196 is a substrate-competitive inhibitor of both SUV4-20 enzymes. In cells, A-196 induced a global decrease in H4K20me2 and H4K20me3 and a concomitant increase in H4K20me1. A-196 inhibited 53BP1 foci formation upon ionizing radiation and reduced NHEJ-mediated DNA-break repair but did not affect homology-directed repair. These results demonstrate the role of SUV4-20 enzymatic activity in H4K20 methylation and DNA repair. A-196 represents a first-in-class chemical probe of SUV4-20 to investigate the role of histone methyltransferases in genomic integrity.
Asunto(s)
Inhibidores Enzimáticos/farmacología , Epigénesis Genética/efectos de los fármacos , Inestabilidad Genómica/efectos de los fármacos , Compuestos Heterocíclicos de 4 o más Anillos/farmacología , N-Metiltransferasa de Histona-Lisina/antagonistas & inhibidores , Línea Celular Tumoral , Cristalografía por Rayos X , Reparación del ADN/efectos de los fármacos , Inhibidores Enzimáticos/química , Compuestos Heterocíclicos de 4 o más Anillos/química , N-Metiltransferasa de Histona-Lisina/metabolismo , Humanos , Metilación/efectos de los fármacos , Modelos Moleculares , Estructura MolecularRESUMEN
In an effort to identify multi-targeted kinase inhibitors with a novel spectrum of kinase activity, a screen of Abbott proprietary KDR inhibitors against a broad panel of kinases was conducted and revealed a series of thienopyridine ureas with promising activity against the Aurora kinases. Modification of the diphenyl urea and C7 moiety of these compounds provided potent inhibitors with good pharmacokinetic profiles that were efficacious in mouse tumor models after oral dosing. Compound 2 (ABT-348) of this series is currently undergoing Phase I clinical trials in solid and hematological cancer populations.
Asunto(s)
Inhibidores de Proteínas Quinasas/farmacología , Piridinas/farmacología , Urea/farmacología , Animales , Antineoplásicos/química , Línea Celular Tumoral , Humanos , Ratones , Inhibidores de Proteínas Quinasas/química , Factor A de Crecimiento Endotelial VascularRESUMEN
We have investigated the SAR of a series of pyrimidinone-containing Cdc7 kinase inhibitors. A wide range of amine substitutions give potent compounds with activities (K(i)) less than 1nM. Kinase selectivity is reasonable and cytotoxicity corresponds to inhibition of MCM2 phosphorylation.
Asunto(s)
Proteínas de Ciclo Celular/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Pirimidinonas/química , Pirimidinonas/farmacología , Aminas/química , Aminas/farmacología , Proteínas de Ciclo Celular/metabolismo , Línea Celular Tumoral , Humanos , Componente 2 del Complejo de Mantenimiento de Minicromosoma , Proteínas Nucleares/metabolismo , Fosforilación/efectos de los fármacos , Proteínas Serina-Treonina Quinasas/metabolismo , Relación Estructura-ActividadRESUMEN
PURPOSE: PARP inhibitors are being developed as therapeutic agents for cancer. More than six compounds have entered clinical trials. The majority of these compounds are ß-nicotinamide adenine dinucleotide (NAD(+))-competitive inhibitors. One exception is iniparib, which has been proposed to be a noncompetitive PARP inhibitor. In this study, we compare the biologic activities of two different structural classes of NAD(+)-competitive compounds with iniparib and its C-nitroso metabolite. EXPERIMENTAL DESIGN: Two chemical series of NAD(+)-competitive PARP inhibitors, iniparib and its C-nitroso metabolite, were analyzed in enzymatic and cellular assays. Viability assays were carried out in MDA-MB-436 (BRCA1-deficient) and DLD1(-/-) (BRCA2-deficient) cells together with BRCA-proficient MDA-MB-231 and DLD1(+/+) cells. Capan-1 and B16F10 xenograft models were used to compare iniparib and veliparib in vivo. Mass spectrometry and the (3)H-labeling method were used to monitor the covalent modification of proteins. RESULTS: All NAD(+)-competitive inhibitors show robust activity in a PARP cellular assay, strongly potentiate the activity of temozolomide, and elicit robust cell killing in BRCA-deficient tumor cells in vitro and in vivo. Cell killing was associated with an induction of DNA damage. In contrast, neither iniparib nor its C-nitroso metabolite inhibited PARP enzymatic or cellular activity, potentiated temozolomide, or showed activity in a BRCA-deficient setting. We find that the nitroso metabolite of iniparib forms adducts with many cysteine-containing proteins. Furthermore, both iniparib and its nitroso metabolite form protein adducts nonspecifically in tumor cells. CONCLUSIONS: Iniparib nonselectively modifies cysteine-containing proteins in tumor cells, and the primary mechanism of action for iniparib is likely not via inhibition of PARP activity.
Asunto(s)
Antineoplásicos/farmacología , Benzamidas/farmacología , Cisteína/química , Inhibidores de Poli(ADP-Ribosa) Polimerasas , Animales , Antineoplásicos/química , Antineoplásicos/uso terapéutico , Proteína BRCA2/deficiencia , Proteína BRCA2/genética , Benzamidas/química , Benzamidas/uso terapéutico , Bencimidazoles/química , Bencimidazoles/farmacología , Bencimidazoles/uso terapéutico , Línea Celular Tumoral , Reparación del ADN/efectos de los fármacos , Dacarbazina/análogos & derivados , Dacarbazina/farmacología , Dacarbazina/uso terapéutico , Sinergismo Farmacológico , Femenino , Humanos , Ratones , Ratones Endogámicos C57BL , Ratones SCID , Neoplasias Experimentales/tratamiento farmacológico , Neoplasias Experimentales/patología , Poli(ADP-Ribosa) Polimerasa-1 , Poli(ADP-Ribosa) Polimerasas/química , Poli(ADP-Ribosa) Polimerasas/metabolismo , Temozolomida , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
Eukaryotic elongation factor-2 kinase (eEF2K) relays growth and stress signals to protein synthesis through phosphorylation and inactivation of eukaryotic elongation factor 2 (eEF2). 1-Benzyl-3-cetyl-2-methylimidazolium iodide (NH125) is a widely accepted inhibitor of mammalian eEF2K and an efficacious anti-proliferation agent against different cancer cells. It implied that eEF2K could be an efficacious anticancer target. However, eEF2K siRNA was ineffective against cancer cells including those sensitive to NH125. To test if pharmacological intervention differs from siRNA interference, we identified a highly selective small molecule eEF2K inhibitor A-484954. Like siRNA, A-484954 had little effect on cancer cell growth. We carefully examined the effect of NH125 and A-484954 on phosphorylation of eEF2, the known cellular substrate of eEF2K. Surprisingly, NH125 increased eEF2 phosphorylation, whereas A-484954 inhibited the phosphorylation as expected for an eEF2K inhibitor. Both A-484954 and eEF2K siRNA inhibited eEF2K and reduced eEF2 phosphorylation with little effect on cancer cell growth. These data demonstrated clearly that the anticancer activity of NH125 was more correlated with induction of eEF2 phosphorylation than inhibition of eEF2K. Actually, induction of eEF2 phosphorylation was reported to correlate with inhibition of cancer cell growth. We compared several known inducers of eEF2 phosphorylation including AMPK activators and an mTOR inhibitor. Interestingly, stronger induction of eEF2 phosphorylation correlated with more effective growth inhibition. We also explored signal transduction pathways leading to NH125-induced eEF2 phosphorylation. Preliminary data suggested that NH125-induced eEF2 phosphorylation was likely mediated through multiple pathways. These observations identified an opportunity for a new multipathway approach to anticancer therapies.
Asunto(s)
Regulación Neoplásica de la Expresión Génica , Imidazoles/farmacología , Factor 2 de Elongación Peptídica/química , Antineoplásicos/farmacología , Línea Celular Tumoral , Proliferación Celular , Diseño de Fármacos , Humanos , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Fosforilación , ARN Interferente Pequeño/metabolismo , Transducción de Señal , Serina-Treonina Quinasas TOR/metabolismo , eIF-2 Quinasa/metabolismoRESUMEN
Although it is increasingly being recognized that drug-target interaction networks can be powerful tools for the interrogation of systems biology and the rational design of multitargeted drugs, there is no generalized, statistically validated approach to harmonizing sequence-dependent and pharmacology-dependent networks. Here we demonstrate the creation of a comprehensive kinome interaction network based not only on sequence comparisons but also on multiple pharmacology parameters derived from activity profiling data. The framework described for statistical interpretation of these network connections also enables rigorous investigation of chemotype-specific interaction networks, which is critical for multitargeted drug design.
Asunto(s)
Farmacogenética/métodos , Proteínas Quinasas/metabolismo , Proteoma/antagonistas & inhibidores , Proteoma/metabolismo , Diseño de Fármacos , Proteoma/análisis , Biología de Sistemas/métodosRESUMEN
BACKGROUND: The insulin-like growth factor (IGF) axis is an important signaling pathway in the growth and survival of many cell and tissue types. This pathway has also been implicated in many aspects of cancer progression from tumorigenesis to metastasis. The multiple roles of IGF signaling in cancer suggest that inhibition of the pathway might yield clinically effective therapeutics. METHODS: We describe A-928605, a novel pyrazolo [3,4-d]pyrimidine small molecule inhibitor of the receptor tyrosine kinases (IGF1R and IR) responsible for IGF signal transduction. This compound was first tested for its activity and selectivity via conventional in vitro kinome profiling and cellular IGF1R autophosphorylation. Additionally, cellular selectivity and efficacy of A-928605 were analyzed in an IGF1R oncogene-addicted cell line by proliferation, signaling and microarray studies. Finally, in vivo efficacy of A-928605 was assessed in the oncogene-addicted cell line and in a neuroblastoma model as a single agent as well as in combination with clinically approved therapeutics targeting EGFR in models of pancreatic and non-small cell lung cancers. RESULTS: A-928605 is a selective IGF1R inhibitor that is able to abrogate activation of the pathway both in vitro and in vivo. This novel compound dosed as a single agent is able to produce significant growth inhibition of neuroblastoma xenografts in vivo. A-928605 is also able to provide additive effects when used in combination with clinically approved agents directed against EGFR in non-small cell lung and human pancreatic tumor models. CONCLUSION: These results suggest that a selective IGF1R inhibitor such as A-928605 may provide a useful clinical therapeutic for IGF pathway affected tumors and warrants further investigation.
Asunto(s)
Proliferación Celular/efectos de los fármacos , Neoplasias/fisiopatología , Proteínas Oncogénicas/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Pirazoles/farmacología , Pirimidinas/farmacología , Receptores de Somatomedina/antagonistas & inhibidores , Animales , Línea Celular Tumoral , Transformación Celular Neoplásica/efectos de los fármacos , Femenino , Humanos , Ratones , Ratones Desnudos , Ratones SCID , Neoplasias/tratamiento farmacológico , Neoplasias/metabolismo , Proteínas Oncogénicas/metabolismo , Fosforilación/efectos de los fármacos , Receptores de Somatomedina/metabolismo , Transducción de Señal/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
A series of isoxazolo[3,4-b]quinoline-3,4(1H,9H)-diones were synthesized as potent inhibitors against Pim-1 and Pim-2 kinases. The structure-activity-relationship studies started from a high-throughput screening hit and was guided by molecular modeling of inhibitors in the active site of Pim-1 kinase. Installing a hydroxyl group on the benzene ring of the core has the potential to form a key hydrogen bond interaction to the hinge region of the binding pocket and thus resulted in the most potent inhibitor, 19, with K(i) values at 2.5 and 43.5 nM against Pim-1 and Pim-2, respectively. Compound 19 also exhibited an activity profile with a high degree of kinase selectivity.
Asunto(s)
Isoxazoles/síntesis química , Isoxazoles/farmacología , Modelos Moleculares , Proteínas Serina-Treonina Quinasas/antagonistas & inhibidores , Proteínas Proto-Oncogénicas c-pim-1/antagonistas & inhibidores , Proteínas Proto-Oncogénicas/antagonistas & inhibidores , Quinolinas/síntesis química , Quinolinas/farmacología , Técnicas Químicas Combinatorias , Cristalografía por Rayos X , Humanos , Isoxazoles/química , Conformación Molecular , Estructura Molecular , Quinolinas/química , Relación Estructura-ActividadRESUMEN
7-Aminopyrazolo[1,5- a]pyrimidine urea receptor tyrosine kinase inhibitors have been discovered. Investigation of structure-activity relationships of the pyrazolo[1,5- a]pyrimidine nucleus led to a series of 6-(4- N, N'-diphenyl)ureas that potently inhibited a panel of vascular endothelial growth factor receptor (VEGFR) and platelet-derived growth factor receptor (PDGFR) kinases. Several of these compounds, such as 34a, are potent inhibitors of kinase insert domain-containing receptor tyrosine kinase (KDR) both enzymatically (<10 nM) and cellularly (<10 nM). In addition, compound 34a possesses a favorable pharmacokinetic profile and demonstrates efficacy in the estradiol-induced murine uterine edema (UE) model (ED 50 = 1.4 mg/kg).
Asunto(s)
Compuestos de Fenilurea/síntesis química , Compuestos de Fenilurea/farmacología , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacología , Pirazoles/síntesis química , Pirazoles/farmacología , Pirimidinas/síntesis química , Pirimidinas/farmacología , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Proteínas Tirosina Quinasas Receptoras/metabolismo , Animales , Edema/tratamiento farmacológico , Edema/enzimología , Femenino , Masculino , Ratones , Modelos Moleculares , Estructura Molecular , Compuestos de Fenilurea/química , Compuestos de Fenilurea/uso terapéutico , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/uso terapéutico , Pirazoles/química , Pirazoles/uso terapéutico , Pirimidinas/química , Pirimidinas/uso terapéutico , Proteínas Tirosina Quinasas Receptoras/química , Relación Estructura-Actividad , Urea/química , Enfermedades Uterinas/tratamiento farmacológico , Enfermedades Uterinas/enzimologíaRESUMEN
Tumor angiogenesis is mediated by KDR and other VEGFR and PDGFR kinases. Their inhibition presents an attractive approach for developing anticancer therapeutics. Here, we report a series of aminopyrazolopyridine ureas as potent VEGFR/PDGFR multitargeted kinase inhibitors. A number of compounds have been identified to be orally bioavailable and efficacious in the mouse edema model.
Asunto(s)
Aminopiridinas/química , Aminopiridinas/farmacología , Inhibidores de Proteínas Quinasas/química , Inhibidores de Proteínas Quinasas/farmacología , Receptores del Factor de Crecimiento Derivado de Plaquetas/antagonistas & inhibidores , Receptores de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Urea/análogos & derivados , Administración Oral , Aminopiridinas/síntesis química , Aminopiridinas/farmacocinética , Animales , Disponibilidad Biológica , Edema/tratamiento farmacológico , Edema/metabolismo , Femenino , Concentración 50 Inhibidora , Ratones , Modelos Moleculares , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/farmacocinética , Pirazoles/síntesis química , Pirazoles/química , Pirazoles/farmacocinética , Pirazoles/farmacología , Relación Estructura-Actividad , Urea/síntesis química , Urea/farmacología , Enfermedades Uterinas/tratamiento farmacológico , Enfermedades Uterinas/metabolismoRESUMEN
As part of a fully integrated and comprehensive strategy to discover novel antibacterial agents, NMR- and mass spectrometry-based affinity selection screens were performed to identify compounds that bind to protein targets uniquely found in bacteria and encoded by genes essential for microbial viability. A biphenyl acid lead series emerged from an NMR-based screen with the Haemophilus influenzae protein HI0065, a member of a family of probable ATP-binding proteins found exclusively in eubacteria. The structure-activity relationships developed around the NMR-derived biphenyl acid lead were consistent with on-target antibacterial activity as the Staphylococcus aureus antibacterial activity of the series correlated extremely well with binding affinity to HI0065, while the correlation of binding affinity with B-cell cytotoxicity was relatively poor. Although further studies are needed to conclusively establish the mode of action of the biphenyl series, these compounds represent novel leads that can serve as the basis for the development of novel antibacterial agents that appear to work via an unprecedented mechanism of action. Overall, these results support the genomics-driven hypothesis that targeting bacterial essential gene products that are not present in eukaryotic cells can identify novel antibacterial agents.
Asunto(s)
Adenosina Trifosfatasas/metabolismo , Antibacterianos/química , Proteínas Bacterianas/metabolismo , Química Farmacéutica/métodos , Haemophilus influenzae/metabolismo , Secuencia de Aminoácidos , Animales , Linfocitos B/metabolismo , Diseño de Fármacos , Genoma Bacteriano , Genómica , Espectroscopía de Resonancia Magnética , Espectrometría de Masas , Datos de Secuencia Molecular , Unión Proteica , Relación Estructura-ActividadRESUMEN
In our continued efforts to search for potent and novel receptor tyrosine kinase (RTK) inhibitors as potential anticancer agents, we discovered, through a structure-based design, that 3-aminoindazole could serve as an efficient hinge-binding template for kinase inhibitors. By incorporating an N,N'-diaryl urea moiety at the C4-position of 3-aminodazole, a series of RTK inhibitors were generated, which potently inhibited the tyrosine kinase activity of the vascular endothelial growth factor receptor and the platelet-derived growth factor receptor families. A number of compounds with potent oral activity were identified by utilizing an estradiol-induced mouse uterine edema model and an HT1080 human fibrosarcoma xenograft tumor model. In particular, compound 17p (ABT-869) was found to possess favorable pharmacokinetic profiles across different species and display significant tumor growth inhibition in multiple preclinical animal models.
Asunto(s)
Inhibidores de la Angiogénesis/síntesis química , Indazoles/síntesis química , Compuestos de Fenilurea/síntesis química , Proteínas Tirosina Quinasas Receptoras/antagonistas & inhibidores , Adenosina Trifosfato/química , Administración Oral , Inhibidores de la Angiogénesis/química , Inhibidores de la Angiogénesis/farmacología , Animales , Sitios de Unión , Edema/inducido químicamente , Edema/patología , Estradiol , Femenino , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Indazoles/química , Indazoles/farmacología , Masculino , Ratones , Modelos Moleculares , Células 3T3 NIH , Compuestos de Fenilurea/química , Compuestos de Fenilurea/farmacología , Fosforilación , Proteínas Tirosina Quinasas Receptoras/química , Proteínas Tirosina Quinasas Receptoras/metabolismo , Relación Estructura-Actividad , Útero/efectos de los fármacos , Útero/patología , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
In 15% to 30% of patients with acute myeloid leukemia (AML), aberrant proliferation is a consequence of a juxtamembrane mutation in the FLT3 gene (FMS-like tyrosine kinase 3-internal tandem duplication [FLT3-ITD]), causing constitutive kinase activity. ABT-869 (a multitargeted receptor tyrosine kinase inhibitor) inhibited the phosphorylation of FLT3, STAT5, and ERK, as well as Pim-1 expression in MV-4-11 and MOLM-13 cells (IC(50) approximately 1-10 nM) harboring the FLT3-ITD. ABT-869 inhibited the proliferation of these cells (IC(50) = 4 and 6 nM, respectively) through the induction of apoptosis (increased sub-G(0)/G(1) phase, caspase activation, and PARP cleavage), whereas cells harboring wild-type (wt)-FLT3 were less sensitive. In normal human blood spiked with AML cells, ABT-869 inhibited phosphorylation of FLT3 (IC(50) approximately 100 nM), STAT5, and ERK, and decreased Pim-1 expression. In methylcellulose-based colony-forming assays, ABT-869 had no significant effect up to 1000 nM on normal hematopoietic progenitor cells, whereas in AML patient samples harboring both FLT3-ITD and wt-FLT3, ABT-869 inhibited colony formation (IC(50) = 100 and 1000 nM, respectively). ABT-869 dose-dependently inhibited MV-4-11 and MOLM-13 flank tumor growth, prevented tumor formation, regressed established MV-4-11 xenografts, and increased survival by 20 weeks in an MV-4-11 engraftment model. In tumors, ABT-869 inhibited FLT3 phosphorylation, induced apoptosis (transferase-mediated dUTP nick-end labeling [TUNEL]) and decreased proliferation (Ki67). ABT-869 is under clinical development for AML.
Asunto(s)
Indazoles/farmacología , Leucemia Mieloide Aguda/tratamiento farmacológico , Compuestos de Fenilurea/farmacología , Inhibidores de Proteínas Quinasas/farmacología , Procesamiento Proteico-Postraduccional/efectos de los fármacos , Tirosina Quinasa 3 Similar a fms/metabolismo , Animales , Apoptosis/efectos de los fármacos , Proliferación Celular/efectos de los fármacos , Relación Dosis-Respuesta a Droga , Quinasas MAP Reguladas por Señal Extracelular/metabolismo , Fase G1/efectos de los fármacos , Células Madre Hematopoyéticas/metabolismo , Humanos , Células K562 , Antígeno Ki-67/biosíntesis , Leucemia Mieloide Aguda/enzimología , Ratones , Fosforilación/efectos de los fármacos , Proteínas Proto-Oncogénicas c-pim-1 , Fase de Descanso del Ciclo Celular/efectos de los fármacos , Factor de Transcripción STAT5/metabolismo , Ensayo de Tumor de Célula Madre , Células U937RESUMEN
A series of substituted thienopyridine ureas was prepared and evaluated for enzymatic and cellular inhibition of KDR kinase activity. Several of these analogs, such as 2, are potent inhibitors of KDR (<10 nM) in both enzymatic and cellular assays. Further characterization of inhibitor 2 indicated that this analog possessed excellent in vivo potency (ED50 2.1 mg/kg) as measured in an estradiol-induced mouse uterine edema model.
Asunto(s)
Piridinas/síntesis química , Urea/síntesis química , Receptor 2 de Factores de Crecimiento Endotelial Vascular/antagonistas & inhibidores , Animales , Modelos Animales de Enfermedad , Edema/inducido químicamente , Estradiol , Femenino , Ratones , Modelos Moleculares , Piridinas/farmacología , Relación Estructura-Actividad , Urea/química , Urea/farmacología , Enfermedades Uterinas/patologíaRESUMEN
We describe the synthesis and antibacterial activity of a series of tetracyclic naphthyridones. The members of this series act primarily via inhibition of bacterial translation and belong to the class of novel ribosome inhibitors (NRIs). In this paper we explore the structure-activity relationships (SAR) of these compounds to measure their ability both to inhibit bacterial translation and also to inhibit the growth of bacterial cells in culture. The most active of these compounds inhibit Streptococcus pneumoniae translation at concentrations of <5 microM and have minimum inhibitory concentrations (MICs) of <8 microg/mL against clinically relevant strains of bacteria.
Asunto(s)
Antibacterianos/síntesis química , Compuestos Heterocíclicos de 4 o más Anillos/síntesis química , Naftiridinas/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , Linfocitos B/efectos de los fármacos , Farmacorresistencia Bacteriana , Compuestos Heterocíclicos de 4 o más Anillos/química , Compuestos Heterocíclicos de 4 o más Anillos/farmacología , Humanos , Pruebas de Sensibilidad Microbiana , Naftiridinas/química , Naftiridinas/farmacología , Biosíntesis de Proteínas/efectos de los fármacos , Estereoisomerismo , Streptococcus pneumoniae/efectos de los fármacos , Streptococcus pneumoniae/genética , Streptococcus pneumoniae/aislamiento & purificación , Relación Estructura-ActividadRESUMEN
A novel series of 6-O-arylpropargyl diazalides was synthesized and evaluated for their antibacterial activity. Members of this series exhibited potent activity against erythromycin-resistant respiratory tract pathogens.
Asunto(s)
Antibacterianos/síntesis química , Antibacterianos/farmacología , Farmacorresistencia Microbiana , Resistencia a Múltiples Medicamentos , Propanoles/síntesis química , Propanoles/farmacología , Streptococcus pneumoniae/efectos de los fármacos , Tilosina/análogos & derivados , Tilosina/síntesis química , Tilosina/farmacología , Antibacterianos/química , Antibacterianos/farmacocinética , Disponibilidad Biológica , Semivida , Pruebas de Sensibilidad Microbiana , Propanoles/química , Relación Estructura-Actividad , Tilosina/químicaRESUMEN
A new reaction of erythronolides, an intramolecular hetero-Diels-Alder, has been discovered. Heated aqueous alcoholic solutions of ABT-773 (1) and its cis isomer (3) convert slowly to cycloadducts 2 and 4, respectively. Optimal reaction conditions, mechanistic studies supported by molecular modeling, and biological activity data are reported. Single-crystal X-ray structures for both adducts 2 and 4 have been obtained.
Asunto(s)
Eritromicina/análogos & derivados , Eritromicina/química , Cetólidos/química , Catálisis , Cristalografía por Rayos X , Ciclización , Conformación Molecular , Estructura Molecular , EstereoisomerismoRESUMEN
Structure-activity relationships for a recently discovered novel ribosome inhibitor (NRI) class of antibacterials were investigated. Preliminary efforts to optimize protein synthesis inhibitory activity of the series through modification of positions 3 and 4 of the naphthyridone lead template resulted in the identification of several biochemically potent analogues. A lack of corresponding whole cell antibacterial activity is thought to be a consequence of poor cellular penetration as evidenced by the enhancement of activity observed for a lead analogue tested in the presence of a cell permeabilizing agent.
Asunto(s)
Antibacterianos/química , Proteínas Bacterianas/antagonistas & inhibidores , Proteínas Bacterianas/biosíntesis , Naftiridinas/química , Inhibidores de la Síntesis de la Proteína/química , Antibacterianos/farmacología , Bacterias Gramnegativas/efectos de los fármacos , Bacterias Gramnegativas/crecimiento & desarrollo , Bacterias Grampositivas/efectos de los fármacos , Bacterias Grampositivas/crecimiento & desarrollo , Pruebas de Sensibilidad Microbiana , Naftiridinas/farmacología , Inhibidores de la Síntesis de la Proteína/farmacología , Relación Estructura-ActividadRESUMEN
The authors report the development of a high-throughput screen for inhibitors of Streptococcus pneumoniae transcription and translation (TT) using a luciferase reporter, and the secondary assays used to determine the biochemical spectrum of activity and bacterial specificity. More than 220,000 compounds were screened in mixtures of 10 compounds per well, with 10,000 picks selected for further study. False-positive hits from inhibition of luciferase activity were an extremely common artifact. After filtering luciferase inhibitors and several known classes of antibiotics, approximately 50 hits remained. These compounds were examined for their ability to inhibit Escherichia coli TT, uncoupled S. pneumoniae translation or transcription, rabbit reticulocyte translation, and in vitro toxicity in human and bacterial cells. One of these compounds had the desired profile of broad-spectrum biochemical activity in bacteria and selectivity versus mammalian biochemical and whole-cell assays.
Asunto(s)
Antibacterianos/farmacología , Pruebas de Sensibilidad Microbiana/métodos , Biosíntesis de Proteínas , Streptococcus pneumoniae/efectos de los fármacos , Transcripción Genética , Antibacterianos/efectos adversos , Secuencia de Bases , Línea Celular Tumoral , ADN Bacteriano , Genes Reporteros , Humanos , Luciferasas/genética , Datos de Secuencia Molecular , Streptococcus pneumoniae/genéticaRESUMEN
We report the discovery and characterization of a novel ribosome inhibitor (NRI) class that exhibits selective and broad-spectrum antibacterial activity. Compounds in this class inhibit growth of many gram-positive and gram-negative bacteria, including the common respiratory pathogens Streptococcus pneumoniae, Haemophilus influenzae, Staphylococcus aureus, and Moraxella catarrhalis, and are nontoxic to human cell lines. The first NRI was discovered in a high-throughput screen designed to identify inhibitors of cell-free translation in extracts from S. pneumoniae. The chemical structure of the NRI class is related to antibacterial quinolones, but, interestingly, the differences in structure are sufficient to completely alter the biochemical and intracellular mechanisms of action. Expression array studies and analysis of NRI-resistant mutants confirm this difference in intracellular mechanism and provide evidence that the NRIs inhibit bacterial protein synthesis by inhibiting ribosomes. Furthermore, compounds in the NRI series appear to inhibit bacterial ribosomes by a new mechanism, because NRI-resistant strains are not cross-resistant to other ribosome inhibitors, such as macrolides, chloramphenicol, tetracycline, aminoglycosides, or oxazolidinones. The NRIs are a promising new antibacterial class with activity against all major drug-resistant respiratory pathogens.