RESUMEN
Targeting energy metabolism in Mycobacterium tuberculosis (Mtb) is a new paradigm in the search for innovative anti-TB drugs. NADH:menaquinone oxidoreductase is a non-proton translocating type II NADH dehydrogenase (NDH-2) that is an essential enzyme in the respiratory chain of Mtb and is not found in mammalian mitochondria. Phenothiazines (PTZs) represent one of the most known class of NDH-2 inhibitors, but their use as anti-TB drugs is currently limited by the wide range of potentially serious off-target effects. In this work, we designed and synthesized a series of new PTZs by decorating the scaffold in an unconventional way, introducing various halogen atoms. By replacing the sulfur atom with selenium, a dibromophenoselenazine 20 was also synthesized. Among the synthesized poly-halogenated PTZs (HPTZs), dibromo and tetrachloro derivatives 9 and 11, along with the phenoselenazine 20, emerged with a better anti-TB profile than the therapeutic thioridazine (TZ). They targeted non-replicating Mtb, were bactericidal, and synergized with rifampin and bedaquiline. Moreover, their anti-TB activity was found to be related to the NDH-2 inhibition. Most important, they showed a markedly reduced affinity to dopaminergic and serotonergic receptors respect to the TZ. From this work emerged, for the first time, as the poly-halogenation of the PTZ core, while permitting to maintain good anti-TB profile could conceivably lead to fewer CNS side-effects risk, making more tangible the use of PTZs for this alternative therapeutic application.
Asunto(s)
Antituberculosos/farmacología , Compuestos de Organoselenio/farmacología , Fenotiazinas/farmacología , Animales , Antituberculosos/síntesis química , Antituberculosos/metabolismo , Antituberculosos/toxicidad , Chlorocebus aethiops , Sinergismo Farmacológico , Inhibidores Enzimáticos/síntesis química , Inhibidores Enzimáticos/metabolismo , Inhibidores Enzimáticos/farmacología , Inhibidores Enzimáticos/toxicidad , Células HEK293 , Humanos , Microsomas Hepáticos/metabolismo , Estructura Molecular , Mycobacterium smegmatis/efectos de los fármacos , Mycobacterium tuberculosis/efectos de los fármacos , NADH Deshidrogenasa/antagonistas & inhibidores , Compuestos de Organoselenio/síntesis química , Compuestos de Organoselenio/metabolismo , Compuestos de Organoselenio/toxicidad , Pruebas de Sensibilidad Parasitaria , Fenotiazinas/síntesis química , Fenotiazinas/metabolismo , Fenotiazinas/toxicidad , Unión Proteica , Receptores de Dopamina D2/metabolismo , Receptores de Serotonina/metabolismo , Relación Estructura-Actividad , Células VeroRESUMEN
This work describes the rational discovery of novel chemotypes of p38α MAPK inhibitors using a funnel approach consisting of several computer-aided drug discovery methods and biological experiments. Among the identified hits, four compounds belonging to different chemical families showed IC50 values lower than 10⯵M. In particular, the 1,4-benzodioxane derivative 5 turned out to be a potent and efficient p38α MAPK inhibitor having IC50â¯=â¯0.07⯵M, and LEexp and LipE values of 0.38 and 4.8, respectively; noteworthy, the compound had also a promising kinase selectivity profile and the capability to suppress p38α MAPK effects in human immune cells. Overall, the collected findings highlight that the applied strategy has been successful in generating chemical novelty in the inhibitor kinase field, providing suitable chemical candidates for further inhibitor optimization.
Asunto(s)
Descubrimiento de Drogas , Proteína Quinasa 14 Activada por Mitógenos/antagonistas & inhibidores , Inhibidores de Proteínas Quinasas/farmacología , Relación Dosis-Respuesta a Droga , Evaluación Preclínica de Medicamentos , Voluntarios Sanos , Humanos , Proteína Quinasa 14 Activada por Mitógenos/metabolismo , Modelos Moleculares , Estructura Molecular , Inhibidores de Proteínas Quinasas/síntesis química , Inhibidores de Proteínas Quinasas/química , Relación Estructura-ActividadRESUMEN
Overexpression of efflux pumps is an important mechanism by which bacteria evade the effects of antimicrobial agents that are substrates. NorA is a Staphylococcus aureus efflux pump that confers reduced susceptibility to many structurally unrelated agents, including fluoroquinolones, biocides, and dyes, resulting in a multidrug resistant (MDR) phenotype. In this work, a series of 2-phenylquinoline derivatives was designed by means of ligand-based pharmacophore modeling in an attempt to identify improved S. aureus NorA efflux pump inhibitors (EPIs). Most of the 2-phenylquinoline derivatives displayed potent EPI activity against the norA overexpressing strain SA-1199B. The antibacterial activity of ciprofloxacin, when used in combination with some of the synthesized compounds, was completely restored in SA-1199B and SA-K2378, a strain overexpressing norA from a multicopy plasmid. Compounds 3m and 3q also showed potent synergistic activity with the ethidium bromide dye in a strain overexpressing the MepA MDR efflux pump.
Asunto(s)
Proteínas Bacterianas/antagonistas & inhibidores , Diseño de Fármacos , Farmacorresistencia Bacteriana/efectos de los fármacos , Proteínas Asociadas a Resistencia a Múltiples Medicamentos/antagonistas & inhibidores , Quinolinas/química , Quinolinas/farmacología , Staphylococcus aureus/efectos de los fármacos , Antibacterianos/síntesis química , Antibacterianos/química , Antibacterianos/farmacología , Técnicas de Química Sintética , Diseño Asistido por Computadora , Evaluación Preclínica de Medicamentos , Concentración 50 Inhibidora , Ligandos , Pruebas de Sensibilidad Microbiana , Modelos Moleculares , Conformación Molecular , Quinolinas/síntesis química , Relación Estructura-ActividadRESUMEN
Tat (transactivator of transcription) is a small HIV protein rich in arginines that interacts with a viral RNA structure called TAR (trans-activation responsive region). Tat-TAR interaction is essential for viral gene expression, replication and pathogenesis. Small molecules able to interfere with TAR and to compete for Tat binding possess antiviral activity due to inhibition of viral transcription and expression, thus impairing formation of infectious virions. We report here, the synthesis and biological evaluation of a new series of quinolone derivatives, namely 2-phenylquinolones, designed with the aim of interfering with the protein/RNA complex. These new derivatives are able to efficiently interfere with Tat/TAR complex in vitro depending on precise structural requirements as demonstrated by fluorescence quenching assay analysis.
Asunto(s)
Fármacos Anti-VIH/síntesis química , Quinolonas/síntesis química , Productos del Gen tat del Virus de la Inmunodeficiencia Humana/metabolismo , Fármacos Anti-VIH/farmacología , Química Farmacéutica/métodos , Diseño de Fármacos , Evaluación Preclínica de Medicamentos , Humanos , Células Jurkat , Cinética , Modelos Químicos , Fragmentos de Péptidos/química , Quinolonas/química , ARN Viral/metabolismo , Espectrometría de Fluorescencia/métodos , Transcripción GenéticaRESUMEN
Established anti-human immunodeficiency virus (HIV) treatments are not always effective or well tolerated, highlighting the need for further refinement of antiviral drug design and development. Given the multitude of molecular targets with which the anti-HIV agents can interact, studies on the mechanism of action of newly discovered HIV inhibitors are quite elaborate. In this article, we describe the use of an efficient reporter system allowing rapid discrimination between a pre- or post-transcriptional mode of action of anti-HIV compounds based on infection by a replication competent HIV-1 molecular clone expressing the green fluorescent protein as part of the nef multiply spliced RNA. Using fluorescence microscopy and flow cytometry, this system enabled us to differentiate between compounds acting at a pre- or post-transciptional level of the virus life cycle. Antiviral activities were determined for four reference compounds as well as one putative novel HIV inhibitor. The results obtained were in agreement with the known characteristics of the reference compounds and revealed that the novel compound interfered with a target before or overlapping with HIV transcription. We showed that during a single replication cycle, compounds inhibiting a molecular target occurring before or coinciding with HIV transcription suppressed GFP expression, whereas compounds interfering at a later stage (such as protease inhibitors, which act after transcription) did not inhibit GFP expression. This GFP-based reporter system is adaptable for high-throughput screening.