RESUMEN
Infections by Staphylococcus aureus have been treated historically with ß-lactam antibiotics. However, these antibiotics have become obsolete in methicillin-resistant S. aureus by acquisition of the bla and mec operons. The presence of the ß-lactam antibiotic is detected by the sensor domains of BlaR and/or MecR, and the information is transmitted to the cytoplasm, resulting in derepression of the antibiotic-resistance genes. We hypothesized that inhibition of the sensor domain would shut down this response system, and ß-lactam susceptibility would be restored. An in silico search of 11 million compounds led to a benzimidazole-based hit and, ultimately, to the boronate 4. The X-ray structure of 4 is covalently engaged with the active-site serine of BlaR. Compound 4 potentiates by 16- to 4,096-fold the activities of oxacillin and of meropenem against methicillin-resistant S. aureus strains. The combination of 4 with oxacillin or meropenem shows efficacy in infected mice, validating the strategy.
RESUMEN
Clostridioides difficile infection (CDI) is the most lethal of the five CDC urgent public health treats, resulting in 12,800 annual deaths in the United States alone [Antibiotic Resistance Threats in the United States, 2019 (2019), www.cdc.gov/DrugResistance/Biggest-Threats.html]. The high recurrence rate and the inability of antibiotics to treat such infections mandate discovery of new therapeutics. A major challenge with CDI is the production of spores, leading to multiple recurrences of infection in 25% of patients [C. P. Kelly, J. T. LaMont, N. Engl. J. Med. 359, 1932-1940 (2008)], with potentially lethal consequence. Herein, we describe the discovery of an oxadiazole as a bactericidal anti-C. difficile agent that inhibits both cell-wall peptidoglycan biosynthesis and spore germination. We document that the oxadiazole binds to the lytic transglycosylase SleC and the pseudoprotease CspC for prevention of spore germination. SleC degrades the cortex peptidoglycan, a critical step in the initiation of spore germination. CspC senses germinants and cogerminants. Binding to SleC is with higher affinity than that to CspC. Prevention of spore germination breaks the nefarious cycles of CDI recurrence in the face of the antibiotic challenge, which is a primary cause of therapeutic failure. The oxadiazole exhibits efficacy in a mouse model of recurrent CDI and holds promise in clinical treatment of CDI.
Asunto(s)
Clostridioides difficile , Clostridioides , Animales , Ratones , Clostridioides/metabolismo , Clostridioides difficile/metabolismo , Peptidoglicano/metabolismo , Esporas Bacterianas/metabolismo , Proteínas Bacterianas/metabolismoRESUMEN
Pressure ulcers (PUs) are chronic wounds that lead to amputations and death. Little is known about why PUs are recalcitrant to healing. Wound healing is mediated by matrix metalloproteinases (MMPs). The 24 MMPs in humans each exist in three forms, of which only one is catalytically competent. We analyzed human PU samples using an affinity resin that exclusively binds to the catalytically competent MMPs. We identified by mass spectrometry the active forms of MMP-1, MMP-8, MMP-9, and MMP-14. Concentrations of MMP-8, MMP-9, and MMP-14 were higher in human PUs compared to the healthy tissue, whereas those for MMP-1 did not change. Decreasing levels of active MMP-9 as the PU improved argued for a detrimental role for this enzyme. In a mouse model of PUs, a highly selective inhibitor for MMP-9 and MMP-14, (R)-ND-336, accelerated wound closure in parallel with significant amelioration of ulcer stage. (R)-ND-336 holds promise as a first-in-class treatment for PUs.
Asunto(s)
Úlcera por Presión , Animales , Metaloproteinasa 1 de la Matriz , Metaloproteinasa 14 de la Matriz , Metaloproteinasa 8 de la Matriz/metabolismo , Metaloproteinasa 9 de la Matriz/metabolismo , Metilaminas , Ratones , Úlcera por Presión/tratamiento farmacológico , Proteómica , Sulfuros , SupuraciónRESUMEN
Clostridioides difficile is a leading health threat. This pathogen initiates intestinal infections during gut microbiota dysbiosis caused by oral administration of antibiotics. C. difficile is difficult to eradicate due to its ability to form spores, which are not susceptible to antibiotics. To address the urgent need for treating recurrent C. difficile infection, antibiotics that selectively target C. difficile over common gut microbiota are needed. We herein describe the class of picolinamide antibacterials which show potent and selective activity against C. difficile. The structure-activity relationship of 108 analogues of isonicotinamide 4, a compound that is equally active against methicillin-resistant Staphylococcus aureus and C. difficile, was investigated. Introduction of the picolinamide core as exemplified by analogue 87 resulted in exquisite potency and selectivity against C. difficile. The ability of the picolinamide class to selectively target C. difficile and to prevent gut dysbiosis holds promise for the treatment of recurrent C. difficile infection.
RESUMEN
Diabetic foot ulcers (DFUs) are a common complication of diabetes that are recalcitrant to healing due to persistent inflammation. The majority of DFUs have bacterial biofilms, with Staphylococcus epidermidis as a predominant bacterium, requiring infection control with antibiotics before treatment of the wound. Matrix metalloproteinases (MMPs) play roles in the pathology and repair of DFUs. However, defining the roles of the 24 human MMPs has been challenging due to the presence of three forms for each MMP, of which only one is catalytically competent, and the lack of convenient methods to distinguish among the three forms of MMPs. Using an affinity resin that binds only to the active forms of MMPs, with identification and quantification by mass spectrometry, we found that infected wounds in mice had increased levels of active MMP-9 compared to uninfected ones, paralleling infected human DFUs. MMP-9 activity prevents diabetic wounds from healing. We evaluated the efficacy of the selective small-molecule MMP-9 inhibitor, (R)-ND-336, in the infected diabetic mouse model of wound healing and showed that (R)-ND-336 alone or in combination with the antibiotic linezolid improves wound healing by inhibiting the detrimental MMP-9, mitigating macrophage infiltration to diminish inflammation, and increasing angiogenesis to restore the normal wound healing process. An advantage of this strategy is the ability to administer (R)-ND-336 concurrently with an antibiotic.
RESUMEN
A major challenge for chemotherapy of bacterial infections is perturbation of the intestinal microbiota. Clostridioides difficile is a Gram-positive bacterium of the gut that can thrive under this circumstance. Its production of dormant and antibiotic-impervious spores results in chronic disruption of normal gut flora and debilitating diarrhea and intestinal infection. C. difficile is responsible for 12,800 deaths per year in the United States. Here, we report the discovery of 2-(4-(3-(trifluoromethoxy)phenoxy)picolinamido)benzo[d]oxazole-5-carboxylate as an antibacterial with potent and selective activity against C. difficile. Its MIC50 and MIC90 (the concentration required to inhibit the growth of 50% and 90% of all the tested strains, respectively) values, documented across 101 strains of C. difficile, are 0.12 and 0.25 µg/mL, respectively. The compound targets cell wall biosynthesis, as assessed by macromolecular biosynthesis assays and by scanning electron microscopy. Animals infected with a lethal dose of C. difficile and treated with compound 1 had a similar survival compared to treatment with vancomycin, which is the frontline antibiotic used for C. difficile infection.
Asunto(s)
Clostridioides difficile , Animales , Antibacterianos/farmacología , Antibacterianos/uso terapéutico , Clostridioides , Ácidos Picolínicos , Vancomicina/farmacologíaRESUMEN
Matrix metalloproteinases (MMPs) play important roles in wound healing, but attribution of their functions in repair of wounds has been challenging. Commonly used tools such as MMP-knockout mice and zymography often confound analysis, which is complicated further as these enzymes exist in three distinct forms with only one being catalytically competent. With the use of topical exogenously administered recombinant MMP-8 and MMP-13 to diabetic and nondiabetic mouse wounds, we show that these proteinases facilitate wound repair by upregulating IL-6 and increasing neutrophil trafficking with an early onset of inflammation. Furthermore, by spatiotemporal control in the use of a selective MMP-2 inhibitor, along with immunoprecipitation and Western blotting, we provide definitive demonstration that MMP-2 does not affect wound healing, contrary to reports. MMP-2 is found in wounds complexed with TIMPs, which is catalytically incompetent.
RESUMEN
We report herein the syntheses of 79 derivatives of the 4(3H)-quinazolinones and their structure-activity relationship (SAR) against methicillin-resistant Staphylococcus aureus (MRSA). Twenty one analogs were further evaluated in in vitro assays. Subsequent investigation of the pharmacokinetic properties singled out compound 73 ((E)-3-(5-carboxy-2-fluorophenyl)-2-(4-cyanostyryl)quinazolin-4(3H)-one) for further study. The compound synergized with piperacillin-tazobactam (TZP) both in vitro and in vivo in a clinically relevant mouse model of MRSA infection. The TZP combination lacks activity against MRSA, yet it synergized with compound 73 to kill MRSA in a bactericidal manner. The synergy is rationalized by the ability of the quinazolinones to bind to the allosteric site of penicillin-binding protein (PBP)2a, resulting in opening of the active site, whereby the ß-lactam antibiotic now is enabled to bind to the active site in its mechanism of action. The combination effectively treats MRSA infection, for which many antibiotics (including TZP) have faced clinical obsolescence.
Asunto(s)
Antibacterianos/química , Antibacterianos/farmacología , Quinazolinonas/química , Quinazolinonas/farmacología , Animales , Antibacterianos/uso terapéutico , Femenino , Ratones , Ratones Endogámicos ICR , Pruebas de Sensibilidad Microbiana/métodos , Neutropenia/tratamiento farmacológico , Neutropenia/microbiología , Quinazolinonas/uso terapéutico , Staphylococcus aureus/efectos de los fármacos , Staphylococcus aureus/fisiología , Relación Estructura-ActividadRESUMEN
A structure-activity relationship (SAR) for the oxadiazole class of antibacterials was evaluated by syntheses of 72 analogs and determination of the minimal-inhibitory concentrations (MICs) against the ESKAPE panel of bacteria. Selected compounds were further evaluated for in vitro toxicity, plasma protein binding, pharmacokinetics (PK), and a mouse model of methicillin-resistant Staphylococcus aureus (MRSA) infection. Oxadiazole 72c shows potent in vitro antibacterial activity, exhibits low clearance, a high volume of distribution, and 41% oral bioavailability, and shows efficacy in mouse models of MRSA infection.
RESUMEN
Diabetic foot ulcers are characterized by hypoxia. For many patients, hyperbaric oxygen (HBO) therapy is the last recourse for saving the limb from amputation, for which the molecular basis is not understood. We previously identified the active form of matrix metalloproteinase-9 (MMP-9) as responsible for diabetic foot ulcer's recalcitrance to healing. Transcription of mmp-9 to the inactive zymogen is upregulated during hypoxia. Activation of the zymogen is promoted by proteases and reactive oxygen species (ROS). We hypothesized that the dynamics of these two events might lead to a lowering of active MMP-9 levels in the wounded tissue. We employed the full-thickness excisional db/db mouse model to study wound healing, and treated the mice to 3.0 atm of molecular oxygen for 90 minutes, 5 days per week for 10 days in an HBO research chamber. Treatment with HBO accelerated diabetic wound healing compared to untreated mice, with more completed and extended reepithelialization. We imaged the wounds for ROS in vivo with a luminol-based probe and found that HBO treatment actually decreases ROS levels. The levels of superoxide dismutase, catalase, and glutathione peroxidase-enzymes that turn over ROS-increased after HBO treatment, hence the observation of decreased ROS. Since ROS levels are lowered, we explored the effect that this would have on activation of MMP-9. Quantitative analysis with an affinity resin that binds and pulls down the active MMPs exclusively, coupled with proteomics, revealed that HBO treatment indeed reduces the active MMP-9 levels. This work for the first time demonstrates that diminution of active MMP-9 is a contributing factor and a mechanism for enhancement of diabetic wound healing by HBO therapy.
Asunto(s)
Diabetes Mellitus Tipo 2/metabolismo , Pie Diabético/metabolismo , Oxigenoterapia Hiperbárica , Metaloproteinasa 9 de la Matriz/metabolismo , Especies Reactivas de Oxígeno/metabolismo , Cicatrización de Heridas , Animales , Catalasa/metabolismo , Modelos Animales de Enfermedad , Precursores Enzimáticos/metabolismo , Glutatión Peroxidasa/metabolismo , Ratones , Receptores de Leptina/genética , Superóxido Dismutasa/metabolismoRESUMEN
The quinazolinones are a new class of antibacterials with in vivo efficacy against methicillin-resistant Staphylococcus aureus (MRSA). The quinazolinones target cell wall biosynthesis and have a unique mechanism of action by binding to the allosteric site of penicillin-binding protein 2a (PBP 2a). We investigated the potential for synergism of a lead quinazolinone with several antibiotics of different classes using checkerboard and time-kill assays. The quinazolinone synergized with ß-lactam antibiotics. The combination of the quinazolinone with commercial piperacillin-tazobactam showed bactericidal synergy at sub-MICs of all three drugs. We demonstrated the efficacy of the triple-drug combination in a mouse MRSA neutropenic thigh infection model. The proposed mechanism for the synergistic activity in MRSA involves inhibition of the ß-lactamase by tazobactam, which protects piperacillin from hydrolysis, which can then inhibit its target, PBP 2. Furthermore, the quinazolinone binds to the allosteric site of PBP 2a, triggering the allosteric response. This leads to the opening of the active site, which, in turn, binds another molecule of piperacillin. In other words, PBP 2a, which is not normally inhibited by piperacillin, becomes vulnerable to inhibition in the presence of the quinazolinone. The collective effect is the impairment of cell wall biosynthesis, with bactericidal consequence. Two crystal structures for complexes of the antibiotics with PBP 2a provide support for the proposed mechanism of action.
Asunto(s)
Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Piperacilina/farmacología , Quinazolinonas/farmacología , Tazobactam/farmacología , Antibacterianos/farmacología , Sinergismo Farmacológico , Pruebas de Sensibilidad MicrobianaRESUMEN
Diabetic foot ulcers (DFUs) are a significant health problem. A single existing FDA-approved drug for this ailment, becaplermin, is not standard-of-care. We previously demonstrated that upregulation of active matrix metalloproteinase (MMP)-9 is the reason that the diabetic wound in mice is recalcitrant to healing and that MMP-8 participates in wound repair. In the present study, we validate the target MMP-9 by identifying and quantifying active MMP-8 and MMP-9 in human diabetic wounds using an affinity resin that binds exclusively to the active forms of MMPs coupled with proteomics. Furthermore, we synthesize and evaluate enantiomerically pure ( R)- and ( S)-ND-336, as inhibitors of the detrimental MMP-9, and show that the ( R)-enantiomer has superior efficacy in wound healing over becaplermin. Our results reveal that the mechanisms of pathology and repair are similar in diabetic mice and diabetic humans and that ( R)-ND-336 holds promise for the treatment of DFUs as a first-in-class therapeutic.
Asunto(s)
Diabetes Mellitus Experimental/tratamiento farmacológico , Pie Diabético/tratamiento farmacológico , Descubrimiento de Drogas , Metaloproteinasa 9 de la Matriz/química , Inhibidores de la Metaloproteinasa de la Matriz/farmacología , Metilaminas/farmacología , Sulfuros/farmacología , Cicatrización de Heridas/efectos de los fármacos , Animales , Diabetes Mellitus Experimental/complicaciones , Diabetes Mellitus Experimental/enzimología , Pie Diabético/enzimología , Pie Diabético/etiología , Femenino , Humanos , Metaloproteinasa 9 de la Matriz/metabolismo , Inhibidores de la Metaloproteinasa de la Matriz/química , Metilaminas/química , Metilaminas/uso terapéutico , Ratones , Ratones Endogámicos C57BL , Proteómica , Sulfuros/química , Sulfuros/uso terapéuticoRESUMEN
The metalloproteinase ADAM10 has been reported as an important target for drug discovery in several human diseases. In this vein, (6S,7S)-N-hydroxy-5-methyl-6-(4-(5-(trifluoromethyl)pyridin-2-yl)piperazine-1-carbonyl)-5-azaspiro[2.5]octane-7-carboxamide (compound 1) has been reported as a selective ADAM10 inhibitor. We synthesized this compound and document that it lacks both potency and selectivity in inhibition of ADAM10. This finding necessitated a structure-based computational analysis to investigate potency and selectivity of ADAM10 inhibition. The model that emerged indeed excluded compound 1 as an inhibitor for ADAM10, while suggesting another reported compound, (1R,3S,4S)-3-(hydroxycarbamoyl)-4-(4-phenylpiperidine-1-carbonyl)cyclohexyl pyrrolidine-1-carboxylate (compound 2), as an ADAM10 selective inhibitor. Compound 2 was synthesized and its potency, and selectivity in inhibition of ADAM10 were documented with a panel of several related enzymes. Pharmacokinetic studies of compound 2 in mice documented that the compound crosses the blood-brain barrier and may be useful as a pharmacological agent or mechanistic tool to delineate the role of ADAM10 in neurological diseases.
RESUMEN
Chronic wounds are a complication of diabetes. Treatment for diabetic foot ulcers is complex with little clinical recourse, resulting in 108,000 lower-limb amputations annually in the United States alone. Matrix metalloproteinases (MMPs) play important roles in the pathology and in the repair of chronic wounds. We previously identified active MMP-8 and MMP-9 in wounds of diabetic mice and determined that MMP-8 accelerates wound repair, while MMP-9 is the culprit for the diabetic wound being refractory to healing. Aclerastide, a peptide analog of angiotensin II, recently failed in phase III clinical trials for treatment of diabetic foot ulcers. We demonstrate herein that treatment of wounds of diabetic mice with aclerastide results in elevated levels of reactive oxygen species and of active MMP-9, which is likely an important contributor to the failure of aclerastide in clinical trials.
Asunto(s)
Angiotensina II/análogos & derivados , Pie Diabético/tratamiento farmacológico , Pie Diabético/metabolismo , Regulación Enzimológica de la Expresión Génica/efectos de los fármacos , Metaloproteinasa 9 de la Matriz/metabolismo , Angiotensina II/farmacología , Angiotensina II/uso terapéutico , Animales , Pie Diabético/enzimología , Pie Diabético/fisiopatología , Femenino , Metaloproteinasa 8 de la Matriz/metabolismo , Ratones , Insuficiencia del Tratamiento , Regulación hacia Arriba/efectos de los fármacos , Cicatrización de Heridas/efectos de los fármacosRESUMEN
Matrix metalloproteinases (MMPs) have numerous physiological functions and share a highly similar catalytic domain. Differential dynamical information on the closely related human MMP-8, -13, and -14 was integrated onto the benzoxazinone molecular template. An in silico library of 28,099 benzoxazinones was generated and evaluated in the context of the molecular-dynamics information. This led to experimental evaluation of 19 synthesized compounds and identification of selective inhibitors, which have potential utility in delineating the physiological functions of MMPs. Moreover, the approach serves as an example of how dynamics of closely related active sites may be exploited to achieve selective inhibition by small molecules and should find applications in other enzyme families with similar active sites.
RESUMEN
In order to address the dire need for new antibiotics to treat specific strains of drug resistant Gram-negative bacterial infections, a mixed ligand analog of the natural Acinetobacter baumannii selective siderophore, fimsbactin, was coupled to daptomycin, a Gram-positive only antibiotic. The resulting conjugate 11 has potent activity against multidrug resistant strains of A. baumannii both in vitro and in vivo. The study also indicates that conjugation of siderophores to "drugs" that are much larger than the siderophore (iron transport agent) itself facilitates active uptake that circumvents the normal permeability problems in Gram-negative bacteria. The results demonstrate the ability to extend activity of a normally Gram-positive only antibiotic to create a potent and targeted Gram-negative antibiotic using a bacterial iron transport based sideromycin Trojan horse strategy.
Asunto(s)
Acinetobacter baumannii/efectos de los fármacos , Daptomicina/química , Daptomicina/farmacología , Sideróforos/química , Farmacorresistencia Bacteriana Múltiple , Humanos , Técnicas In VitroRESUMEN
Matrix metalloproteinase (MMP)-2 knockout (KO) mice show impaired neurological recovery after spinal cord injury (SCI), suggesting that this proteinase is critical to recovery processes. However, this finding in the KO has been confounded by a compensatory increase in MMP-9. We synthesized the thiirane mechanism-based inhibitor ND-378 and document that it is a potent (nanomolar) and selective slow-binding inhibitor of MMP-2 that does not inhibit the closely related MMP-9 and MMP-14. ND-378 crosses the blood-spinal cord barrier, achieving therapeutic concentrations in the injured spinal cord. Spinal-cord injured mice treated with ND-378 showed no change in long-term neurological outcomes, suggesting that MMP-2 is not a key determinant of locomotor recovery.
Asunto(s)
Metaloproteinasa 2 de la Matriz/metabolismo , Inhibidores de la Metaloproteinasa de la Matriz/farmacología , Éteres Fenílicos/farmacología , Recuperación de la Función/fisiología , Traumatismos de la Médula Espinal/enzimología , Médula Espinal/enzimología , Sulfonas/farmacología , Animales , Modelos Animales de Enfermedad , Diseño de Fármacos , Evaluación Preclínica de Medicamentos , Masculino , Metaloproteinasa 14 de la Matriz/metabolismo , Metaloproteinasa 2 de la Matriz/genética , Metaloproteinasa 9 de la Matriz/metabolismo , Inhibidores de la Metaloproteinasa de la Matriz/síntesis química , Inhibidores de la Metaloproteinasa de la Matriz/farmacocinética , Ratones , Ratones Noqueados , Simulación del Acoplamiento Molecular , Estructura Molecular , Actividad Motora/efectos de los fármacos , Actividad Motora/fisiología , Éteres Fenílicos/síntesis química , Éteres Fenílicos/farmacocinética , Recuperación de la Función/efectos de los fármacos , Médula Espinal/efectos de los fármacos , Traumatismos de la Médula Espinal/tratamiento farmacológico , Sulfonas/síntesis química , Sulfonas/farmacocinéticaRESUMEN
The oxadiazole antibacterials target the bacterial cell wall and are bactericidal. We investigated the synergism of ND-421 with the commonly used ß-lactams and non-ß-lactam antibiotics by the checkerboard method and by time-kill assays. ND-421 synergizes well with ß-lactam antibiotics, and it also exhibits a long postantibiotic effect (4.7 h). We also evaluated the in vivo efficacy of ND-421 in a murine neutropenic thigh infection model alone and in combination with oxacillin. ND-421 has in vivo efficacy by itself in a clinically relevant infection model (1.49 log10 bacterial reduction for ND-321 versus 0.36 log10 for linezolid with NRS119) and acts synergistically with ß-lactam antibiotics in vitro and in vivo, and the combination of ND-421 with oxacillin is efficacious in a mouse neutropenic thigh methicillin-resistant Staphylococcus aureus (MRSA) infection model (1.60 log10 bacterial reduction). The activity of oxacillin was potentiated in the presence of ND-421, as the strain would have been resistant to oxacillin otherwise.
Asunto(s)
Antibacterianos/farmacología , Staphylococcus aureus Resistente a Meticilina/efectos de los fármacos , Oxadiazoles/farmacología , Infecciones Estafilocócicas/tratamiento farmacológico , beta-Lactamas/farmacología , Animales , Modelos Animales de Enfermedad , Sinergismo Farmacológico , Femenino , Ratones , Ratones Endogámicos ICR , Pruebas de Sensibilidad Microbiana , Oxacilina/farmacologíaRESUMEN
Here, we report the synthesis and evaluation of dual drug-loaded nanoparticles as an effective means to deliver carfilzomib and doxorubicin to multiple myeloma tumor cells at their optimal synergistic ratio. First, various molar ratios of carfilzomib to doxorubicin were screened against multiple myeloma cell lines to determine the molar ratio that elicited the greatest synergy using the Chou-Talalay method. The therapeutic agents were then incorporated into liposomes at the optimal synergistic ratio of 1:1 to yield dual drug-loaded nanoparticles with a narrow size range of 115 nm and high reproducibility. Our results demonstrated that the dual drug-loaded liposomes exhibited synergy in vitro and were more efficacious in inhibiting tumor growth in vivo than a combination of free drugs, while at the same time reducing systemic toxicity. Taken together, this study presents the synthesis and preclinical evaluation of dual drug-loaded liposomes containing carfilzomib and doxorubicin for enhanced therapeutic efficacy to improve patient outcome in multiple myeloma. Mol Cancer Ther; 15(7); 1452-9. ©2016 AACR.
Asunto(s)
Doxorrubicina/administración & dosificación , Liposomas , Nanopartículas , Oligopéptidos/administración & dosificación , Animales , Línea Celular Tumoral , Modelos Animales de Enfermedad , Relación Dosis-Respuesta a Droga , Doxorrubicina/química , Combinación de Medicamentos , Composición de Medicamentos , Evaluación Preclínica de Medicamentos , Sinergismo Farmacológico , Humanos , Liposomas/química , Ratones , Estructura Molecular , Mieloma Múltiple/tratamiento farmacológico , Mieloma Múltiple/patología , Nanopartículas/química , Oligopéptidos/química , Carga Tumoral/efectos de los fármacos , Ensayos Antitumor por Modelo de XenoinjertoRESUMEN
We recently reported on the discovery of a novel antibacterial (2) with a 4(3H)-quinazolinone core. This discovery was made by in silico screening of 1.2 million compounds for binding to a penicillin-binding protein and the subsequent demonstration of antibacterial activity against Staphylococcus aureus. The first structure-activity relationship for this antibacterial scaffold is explored in this report with evaluation of 77 variants of the structural class. Eleven promising compounds were further evaluated for in vitro toxicity, pharmacokinetics, and efficacy in a mouse peritonitis model of infection, which led to the discovery of compound 27. This new quinazolinone has potent activity against methicillin-resistant (MRSA) strains, low clearance, oral bioavailability and shows efficacy in a mouse neutropenic thigh infection model.