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OBJECTIVES: Slow-growing nontuberculous mycobacteria (NTMs) are highly prevalent and routinely cause opportunistic intracellular infectious disease in immunocompromised hosts. METHODS: The activity of the triple combination of antibiotics, clarithromycin (CLR), rifabutin (RFB), and clofazimine (CFZ), was evaluated and compared with the activity of single antibiotics as well as with double combinations in an in vitro biofilm assay and an in vivo murine model of Mycobacterium avium subsp. hominissuis (M. avium) lung infection. RESULTS: Treatment of 1-week-old biofilms with the triple combination exerted the strongest effect of all (0.12 ± 0.5 × 107 CFU/mL) in reducing bacterial growth as compared to the untreated (5.20 ± 0.5 × 107/mL) or any other combination (≥0.75 ± 0.6 × 107/mL) by 7 days. The treatment of mice intranasally infected with M. avium with either CLR and CFZ or the triple combination provided the greatest reduction in CLR-sensitive M. avium bacterial counts in both the lung and spleen compared to any single antibiotic or remaining double combination by 4 weeks posttreatment. After 4 weeks of treatment with the triple combination, there were no resistant colonies detected in mice infected with a CLR-resistant strain. No clear relationships between treatment and spleen or lung organ weights were apparent after triple combination treatment. CONCLUSIONS: The biofilm assay data and mouse disease model efficacy results support the further investigation of the triple-antibiotic combination.
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Upamostat is an orally available small-molecule serine protease inhibitor that is a highly potent inhibitor of trypsin 1, trypsin 2, trypsin 3 (PRSS1/2/3), and the urokinase-type plasminogen activator (uPA). These enzymes are expressed in many cancers, especially during tissue remodeling and subsequent tumor cell invasion. Opaganib (ABC294640), a novel, orally available small molecule is a selective inhibitor of the phosphorylation of sphingosine to sphingosine-1-phosphate (S-1-P) by sphingosine kinase 2 (SPHK2). Both sphingosine kinase 1 (SPHK1) and SPHK2 are known to regulate the proliferation-inducing compound S-1-P. However, SPHK2 is more critical in cancer pathogenesis. The goal of this project was to investigate the potential antitumor effects of upamostat and opaganib, individually and in combination, on cholangiocarcinoma (CCA) xenografts in nude mice. PAX165, a patient-derived xenograft (PDX) from a surgically resected CCA, expresses substantial levels of SPHK2, PRSS1, PRSS2, and PRSS3. Four groups of 18 mice each were treated with upamostat, opaganib, both, or vehicle. Mouse weights and PAX165 tumor volumes were measured. Tumor volumes in the upamostat, opaganib, and upamostat plus opaganib groups were significantly decreased compared to the control group.
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OBJECTIVES: We performed a pilot study of upamostat, a serine protease inhibitor, in outpatients with symptomatic COVID-19 before a pivotal trial. METHODS: SARS-CoV-2 patients with ≥2 moderate-severe symptoms onset within 5 days were randomized to oral upamostat 200 or 400 mg or placebo daily for 14 days. Patients completed COVID-19 symptom questionnaires daily for 28 days, then thrice weekly for 4 weeks, and underwent physical and laboratory examinations periodically. RESULTS: A total of 61 patients enrolled of which 20 received a placebo or upamostat 200 mg daily; 21 received upamostat 400 mg daily. Treatment was well tolerated; only one patient (upamostat 400) reported a drug-related adverse event, mild skin rash; no patient discontinued owing to a drug-related adverse event. The median time to a sustained recovery from severe symptoms was 8, 4, and 3 days for the three treatment groups, respectively. New severe symptoms developed in 20% of the placebo group vs 2.4% in the combined upamostat groups, (Pâ¯=â¯0.036). Three placebo patients (15%) versus no upamostat patients were hospitalized for worsening COVID (P= 0.03). The mean d-dimer level remained constant in placebo patients but decreased by 38% and 48% in upamostat 200 and 400 patients, respectively. CONCLUSION: Upamostat was well tolerated, shortened recovery time, and decreased new severe symptoms and hospitalization.
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COVID-19 , Humanos , SARS-CoV-2 , Projetos Piloto , Pacientes Ambulatoriais , Inibidores de Serina Proteinase , Resultado do Tratamento , Método Duplo-CegoRESUMO
Background: Opaganib, an oral sphingosine kinase-2 inhibitor with antiviral and anti-inflammatory properties, was shown to inhibit severe acute respiratory syndrome coronavirus 2 replication in vitro. We thus considered that opaganib could be beneficial for moderate to severe coronavirus disease 2019 (COVID-19) pneumonia. The objective of the study was to evaluate the safety of opaganib and its effect on supplemental oxygen requirements and time to hospital discharge in COVID-19 pneumonia hospitalized patients requiring supplemental oxygen. Methods: This Phase 2a, randomized, double-blind, placebo-controlled study was conducted between July and December 2020 in 8 sites in the United States. Forty-two enrolled patients received opaganib (n = 23) or placebo (n = 19) added to standard of care for up to 14 days and were followed up for 28 days after their last dose of opaganib/placebo. Results: There were no safety concerns arising in this study. The incidence of ≥Grade 3 treatment-emergent adverse events was 17.4% and 33.3% in the opaganib and placebo groups, respectively. Three deaths occurred in each group. A numerical advantage for opaganib over placebo was observed in in this nonpowered study reflected by total supplemental oxygen requirement from baseline to Day 14, the requirement for supplemental oxygen for at least 24â hours by Day 14, and hospital discharge. Conclusions: In this proof-of-concept study, hypoxic, hospitalized patients receiving oral opaganib had a similar safety profile to placebo-treated patients, with preliminary evidence of benefit for opaganib as measured by supplementary oxygen requirement and earlier hospital discharge. These findings support further evaluation of opaganib in this population.
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The Covid-19 pandemic driven by the SARS-CoV-2 virus continues to exert extensive humanitarian and economic stress across the world. Although antivirals active against mild disease have been identified recently, new drugs to treat moderate and severe Covid-19 patients are needed. Sphingolipids regulate key pathologic processes, including viral proliferation and pathologic host inflammation. Opaganib (aka ABC294640) is a first-in-class clinical drug targeting sphingolipid metabolism for the treatment of cancer and inflammatory diseases. Recent work demonstrates that opaganib also has antiviral activity against several viruses including SARS-CoV-2. A recently completed multinational Phase 2/3 clinical trial of opaganib in patients hospitalized with Covid-19 demonstrated that opaganib can be safely administered to these patients, and more importantly, resulted in a 62% decrease in mortality in a large subpopulation of patients with moderately severe Covid-19. Furthermore, acceleration of the clearance of the virus was observed in opaganib-treated patients. Understanding the biochemical mechanism for the anti-SARS-CoV-2 activity of opaganib is essential for optimizing Covid-19 treatment protocols. Opaganib inhibits three key enzymes in sphingolipid metabolism: sphingosine kinase-2 (SK2); dihydroceramide desaturase (DES1); and glucosylceramide synthase (GCS). Herein, we describe a tripartite model by which opaganib suppresses infection and replication of SARS-CoV-2 by inhibiting SK2, DES1 and GCS. The potential impact of modulation of sphingolipid signaling on multi-organ dysfunction in Covid-19 patients is also discussed.
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Tratamento Farmacológico da COVID-19 , Adamantano/análogos & derivados , Antivirais/farmacologia , Antivirais/uso terapêutico , Humanos , Pandemias , Piridinas , SARS-CoV-2 , EsfingolipídeosRESUMO
The article aims to identify the main problems in treating urological pathologies by analyzing scientific literature from this field and developing recommendations. The quantitative excretion of uric acid, urine volume, and pH are essential in the formation of uric acid stones. The most important risk factor for uric acid nephrolithiasis is the acidic reaction of urine, which is a prerequisite for the formation of urinary stones. When urine is alkalized, the pH should be 6-6.5. Drugs alkalize urine, and one should titrate using urine pH indicator paper until the level is stable. This study found that the spread of genitourinary diseases is increasing. This situation can be improved by monitoring and assessing epidemiological processes, preventing urological pathology, and optimizing medical care organization in the context of health care reform.
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Cálculos Renais , Urolitíase , Feminino , Humanos , Concentração de Íons de Hidrogênio , Cálculos Renais/diagnóstico , Cálculos Renais/etiologia , Cálculos Renais/urina , Masculino , Fatores de Risco , Ácido Úrico , Urolitíase/diagnóstico , Urolitíase/epidemiologia , Urolitíase/terapiaRESUMO
The present COVID-19 epidemic is a threat to physical health and brings a drain to Quality of life and mental health in the general population. However, changes in Quality of life and mental health status due to pandemic-related is less known. This study was implemented to investigate and predict changes in the Quality of life and psychological changes in people worldwide due to the pandemic. 3002 individuals participated in an online survey. The result showed that Quality of life is significantly decreased over time, meanwhile perceived stress level is raised significantly, and an increased level of difficulty in emotion regulation has happened. Almost everyone faced with increased perceived stress and current quarantine experience were significant predictors of perceived stress escalation. Younger people and individuals who had a worsening quality of life response tended to show more stress and emotion regulation problems. Furthermore, prediction models show that by extending the time of quarantine, Quality of life will worsen, and therefore the rate of perceived stress will be higher, and the problem with emotion regulation will arise more. As the whole world faces the pandemic, this research provides several implications for public mental health intervention.
L'épidémie actuelle de COVID-19 est une menace pour la santé physique et pèse sur la qualité de vie et la santé mentale de la population générale. Cependant, les changements dans la qualité de vie et l'état de santé mentale dus à la pandémie sont moins connus. Cette étude a été mise en Åuvre pour étudier et prédire les changements dans la qualité de vie et les changements psychologiques chez les personnes dans le monde en raison de la pandémie. Trois mille et deux personnes ont participé à une enquête en ligne. Le résultat a montré que la qualité de vie diminue considérablement au fil du temps, que le niveau de stress perçu augmente de manière significative et que la régulation des émotions est plus difficile. Presque tous les sujets confrontés à une augmentation du stress et à une quarantaine étaient des prédicteurs significatifs de l'escalade du stress perçu. Les jeunes et les individus dont la qualité de vie se détériorait avaient tendance à présenter davantage de problèmes de stress et de régulation des émotions. De plus, les modèles de prédiction montrent qu'en prolongeant la durée de la quarantaine, la qualité de vie se détériore, le taux de stress perçu est plus élevé, et le problème de la régulation des émotions se pose davantage. Alors que le monde entier fait face à la pandémie, cette recherche fournit plusieurs pistes pour l'intervention publique en santé mentale.
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OBJECTIVES: Prospective data evaluating the effect of ondansetron on the corrected QT (QTc) interval is lacking in emergency department clinical use. As part of a randomized trial of a 24-mg bimodal-release ondansetron (RHB-102) pill, we tested the effect of RHB-102 compared to placebo on QTc change. METHODS: This was a planned safety outcome analysis within a multicenter, double-blind, placebo-controlled trial. The trial compared the effects of RHB-102 among patients ≥12 years who presented to 21 centers with symptoms of acute gastroenteritis. Patients with an initial baseline electrocardiogram as well as a follow-up electrocardiogram 4 h later were included in the analysis. The safety endpoint for this analysis was the change from baseline in QTc interval at 4 h, the median time at which ondansetron serum level peaks. RESULTS: A total of 147 patients were included with a mean baseline QTc in the RHB-102 and placebo arms of 410 and 406 ms, respectively. There was no difference in the change in QTc at 4 h post-study drug administration between the RHB-102 (+4, 95% CI 1-8 ms) and placebo group (+5, 95% CI 1-9 ms). In the RHB-102 arm, 6.6% of patients had a QTc change >30 ms and in the placebo arm 3.6% (p = 0.48). No patient in either arm had a QTc change >60 ms after study drug administration. CONCLUSION: In patients with normal baseline QTc, 24-mg bimodal-release ondansetron did not prolong the QTc in comparison to placebo.
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Antieméticos/administração & dosagem , Gastroenterite/tratamento farmacológico , Síndrome do QT Longo/induzido quimicamente , Ondansetron/administração & dosagem , Administração Oral , Adolescente , Adulto , Antieméticos/efeitos adversos , Antieméticos/farmacologia , Preparações de Ação Retardada/administração & dosagem , Método Duplo-Cego , Serviço Hospitalar de Emergência/estatística & dados numéricos , Feminino , Humanos , Masculino , Uso Off-Label , Ondansetron/efeitos adversos , Ondansetron/farmacologia , Estudos Prospectivos , Adulto JovemRESUMO
INTRODUCTION: Previous, small studies have suggested that ondansetron has beneficial effects in diarrhea-predominant irritable bowel syndrome (IBS-D). This randomized, double-blind study evaluated the efficacy and safety of daily 12 mg RHB-102, an investigational bimodal release ondansetron tablet, in IBS-D. METHODS: Men and women with IBS-D by the Rome III criteria, Bristol Stool Scale ≥6 on 2 or more days weekly, and average daily worst pain intensity ≥3/10 were randomized 60:40 to RHB-102 or placebo once daily for 8 weeks. The primary end point was overall stool consistency response for at least 4 of 8 weeks. Secondary end points included overall worst abdominal pain and overall composite response, defined as response on both abdominal pain and stool consistency end points. RESULTS: Overall stool consistency response rates were 56.0% and 35.3% (RHB-102 vs placebo, P = 0.036) and similar among male and female patients. Overall pain response (50.7% vs 39.2%) and composite response rates (40.0% vs 25.5%) favored RHB-102, although these differences were not statistically significant. Stool consistency response rates were enhanced in patients with baseline C-reactive protein above the median (2.09 mg/L), 59.5%, vs 23.1% (P = 0.009). Overall rates of adverse events were similar, with a higher rate of constipation in RHB-102 patients (13.3% vs 3.9%) that resolved rapidly on withholding treatment. DISCUSSION: RHB-102 was effective and safe in the treatment of men and women with IBS-D. Baseline C-reactive protein seemed to be predictive of response.
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Dor Abdominal/tratamento farmacológico , Defecação/efeitos dos fármacos , Diarreia/tratamento farmacológico , Fármacos Gastrointestinais/uso terapêutico , Síndrome do Intestino Irritável/tratamento farmacológico , Ondansetron/uso terapêutico , Adolescente , Adulto , Idoso , Método Duplo-Cego , Feminino , Fármacos Gastrointestinais/administração & dosagem , Fármacos Gastrointestinais/efeitos adversos , Humanos , Masculino , Pessoa de Meia-Idade , Ondansetron/administração & dosagem , Ondansetron/efeitos adversos , Resultado do Tratamento , Adulto JovemRESUMO
Purpose: Combination of benzoyl peroxide (BPO) with topical antibiotics can lead to higher efficacy and less bacterial resistance, but it in turn increases adverse effects such as skin irritability and dryness. In this study, the efficacy of combination therapy of niosomal BPO 1% and clindamycin (CL) 1% is compared with niosomal CL in acne vulgaris. Methods: This is a double-blind clinical trial study on 100 patients with acne vulgaris in Afzalipour hospital in Kerman. Patients were randomly divided into 2 groups (case and control). The case group received niosomal combination of BPO 1% and CL 1%.The control group received niosomal CL1%. The efficacy of treatment protocols was evaluated in 2nd, 4th, 8th and 12th weeks of treatment by counting lesions (severity and grading acne lesions) and quality of life (QoL). Furthermore, side effect were evaluated at each treatment visits. Results: The reduction in mean percentage of acne lesions in case group (treated with BPO 1% and CL1%) (64.21%) was higher than control group (treated with niosomal CL 1%) (59.04%), but the statistical difference was not significant. Sum of excellent and good results were found in 80% and 76.1% of case and control groups, respectively (P=0.377). Also adding BPO to the treatment formulation in case group did not increase adverse effects, as statistical difference between 2 groups was not significant. Conclusion: Combination of niosomal BPO 1% and CL 1% in treatment of acne vulgaris showed higher efficacy with no increase in adverse effects in comparison with niosomal CL 1%, but the statistical difference was not significant.
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Importance: Vomiting resulting from acute gastroenteritis is commonly treated with intravenous antiemetics in acute care settings. If oral treatment were beneficial, patients might not need intravenous administered hydration or medication. Furthermore, a long-acting treatment could provide sustained relief from nausea and vomiting. Objective: To determine whether an experimental long-acting bimodal release ondansetron tablet decreases gastroenteritis-related vomiting and eliminates the need for intravenous therapy for 24 hours after administration. Design, Setting, and Participants: This placebo-controlled, double-blind, randomized clinical trial included patients from 19 emergency departments and 2 urgent care centers in the United States from December 8, 2014, to February 17, 2017. Patients 12 years and older with at least 2 vomiting episodes from presumed gastroenteritis in the previous 4 hours and symptoms with less than 36 hours' duration were randomized using a 3:2 active to placebo ratio. Analyses were performed on an intent-to-treat basis and conducted from June 1, 2017, to November 1, 2017. Intervention: Bimodal release ondansetron tablet containing 6 mg of immediate release ondansetron and 18 mg of a 24-hour release matrix for a total of 24 mg of ondansetron. Main Outcomes and Measures: Treatment success was defined as no further vomiting, no need for rescue medication, and no intravenous hydration for 24 hours after bimodal release ondansetron administration. Results: Analysis included 321 patients (mean [SD] age, 29.0 [11.1] years; 195 [60.7%] women), with 192 patients in the bimodal release ondansetron group and 129 patients in the placebo group. Treatment successes were observed in 126 patients in the bimodal release ondansetron group (65.6%) compared with 70 patients in the placebo group (54.3%), with an 11.4% (95% CI, 0.3%-22.4%) absolute probability difference. The proportion of treatment success was 21% higher among patients who received bimodal release ondansetron compared with those who received a placebo (relative risk, 1.21; 95% CI, 1.00-1.46; P = .04). In an analysis including only patients with a discharge diagnosis of acute gastroenteritis and no major protocol violations, there were 123 treatment successes (69.5%) in the bimodal release ondansetron group compared with 67 treatment successes (54.9%) in the placebo group (relative risk, 1.27; 95% CI, 1.05-1.53; P = .01). Adverse effects were infrequent and similar to the known safety profile of ondansetron. Conclusions and Relevance: This randomized clinical trial found that a long-acting bimodal release oral ondansetron tablet was an effective antiemetic among adolescents and adults with moderate to severe vomiting from acute gastroenteritis. The drug benefits extended to 24 hours after administration. Bimodal release ondansetron may decrease the need for intravenous access and emergency department care to manage acute gastroenteritis. Trial Registration: ClinicalTrials.gov identifier: NCT02246439.
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Gastroenterite/tratamento farmacológico , Ondansetron/normas , Administração Oral , Adolescente , Adulto , Antieméticos/uso terapêutico , Método Duplo-Cego , Feminino , Humanos , Ondansetron/uso terapêutico , Resultado do Tratamento , Vômito/tratamento farmacológicoRESUMO
BACKGROUND: 1,25 Dihydroxyvitamin D3 (1,25(OH)2D3) modulates inflammation and immune responses. Deficiency of 1,25(OH)2D3 was found to be associated with the risk of cancer, cardiovascular disease, osteoarthritis, infections, and autoimmune diseases. This study evaluated the effect of 1,25 dihydroxyvitamin D3 1,25(OH)2D3 on thioacetamide (TAA)-induced acute liver injury in rats. MATERIALS AND METHODS: Rats were treated with either saline or 1,25(OH)2D3 (0.30 µg/kg; orogastrically) for 15 d. Starting from day 13, TAA (200 mg/kg; intraperitoneally) was given for 3 d. On day 15, all rats were euthanized. Liver and blood samples were collected. RESULTS: TAA caused severe damage, increased lipid peroxidation with reductions in endogenous antioxidants, increased apoptosis, increased production of reactive oxygen species, and elevated inducible nitric oxide synthase (iNOS), and nuclear factor kappa B (NF-κB) expression in liver. Extent of damage was decreased by 1,25(OH)2D3 (P < 0.01). 1,25(OH)2D3 attenuated the increase in malondialdehyde (P < 0.01), increase in myeloperoxidase (P < 0.01), increase in chemiluminescence levels (P < 0.05) and apoptotic activity (P < 0.001). Elevated liver iNOS and NF-κB expression in TAA group was also reduced by 1,25(OH)2D3 (P < 0.001, for iNOS; P < 0.001, for NF-κB). TAA group revealed high serum aspartate transaminase and alanine transaminase (ALT) activities (P < 0.01, for aspartate transaminase; P = 0.08, for ALT) and reduced albumin levels (P < 0.01) compared with control. 1,25(OH)2D3 had no statistically significant effect on these parameters. CONCLUSIONS: 1,25(OH)2D3 provides protection against hepatic injury in a rat model of TAA-induced hepatotoxicity via suppression of inflammatory reaction, oxidative stress, and apoptosis.
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Calcitriol/uso terapêutico , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Avaliação Pré-Clínica de Medicamentos , Animais , Apoptose/efeitos dos fármacos , Calcitriol/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/patologia , Feminino , Fígado/efeitos dos fármacos , Fígado/enzimologia , Fígado/patologia , Distribuição Aleatória , Ratos Sprague-Dawley , TioacetamidaRESUMO
As the smallest and simplest motor enzymes, kinesins have served as the prototype for understanding the relationship between protein structure and mechanochemical function of enzymes in this class. Conventional kinesin (kinesin-1) is a motor enzyme that transports cargo toward the plus end of microtubules by a processive, asymmetric hand-over-hand mechanism. The coiled-coil neck domain, which connects the two kinesin motor domains, contributes to kinesin processivity (the ability to take many steps in a row) and is proposed to be a key determinant of the asymmetry in the kinesin mechanism. While previous studies have defined the orientation and position of microtubule-bound kinesin motor domains, the disposition of the neck coiled-coil remains uncertain. We determined the neck coiled-coil orientation using a multidonor fluorescence resonance energy transfer (FRET) technique to measure distances between microtubules and bound kinesin molecules. Microtubules were labeled with a new fluorescent taxol donor, TAMRA-X-taxol, and kinesin derivatives with an acceptor fluorophore attached at positions on the motor and neck coiled-coil domains were used to reconstruct the positions and orientations of the domains. FRET measurements to positions on the motor domain were largely consistent with the domain orientation determined in previous studies, validating the technique. Measurements to positions on the neck coiled-coil were inconsistent with a radial orientation and instead demonstrated that the neck coiled-coil is parallel to the microtubule surface. The measured orientation provides a structural explanation for how neck surface residues enhance processivity and suggests a simple hypothesis for the origin of kinesin step asymmetry and "limping."
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Proteínas de Drosophila/química , Cinesinas/química , Proteínas Motores Moleculares/química , Animais , Sítios de Ligação , Fenômenos Biofísicos , Proteínas de Drosophila/metabolismo , Transferência Ressonante de Energia de Fluorescência , Corantes Fluorescentes/química , Cinesinas/metabolismo , Microtúbulos/metabolismo , Modelos Moleculares , Proteínas Motores Moleculares/metabolismo , Paclitaxel/análogos & derivados , Paclitaxel/química , Ligação Proteica , Multimerização Proteica , Estrutura Quaternária de Proteína , Rodaminas/químicaRESUMO
A practical one-pot synthetic strategy for the efficient synthesis of a range of structurally interesting and bioactive quinoline-based tetracycles has been developed. A key step in the synthesis is a tandem three-component reaction of heteroaromatic amine, methyl 2-formylbenzoate and (t)butyl isonitrile, followed by TFA-mediated lactamization via intramolecular aminolysis of an adjacent ester. Results related to a kinase-panel screening for several selected compounds are also discussed in this article.
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Compostos Heterocíclicos de 4 ou mais Anéis/síntese química , Quinolinas/síntese química , Aminas/química , Benzoatos/química , Ésteres/química , Lactamas/química , Modelos Químicos , Nitrilas/química , Fosfotransferases/antagonistas & inibidores , Fosfotransferases/metabolismoRESUMO
A one-pot synthesis of diverse benzofurans and indoles from readily available starting materials was achieved via the sequential Ugi four-component reaction, intramolecular Diels-Alder reaction, and oxidative aromatization.
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The Pd-catalyzed copper-free carbonylative Sonogashira coupling reaction to synthesize alkynyl ketones from terminal alkynes and aryl iodides was achieved by using water as a solvent. The reaction was carried out at room temperature under balloon pressure of CO with Et(3)N as a base. The developed method was successfully applied to the synthesis of flavones.
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Alcinos/química , Flavonas/síntese química , Hidrocarbonetos Iodados/química , Cetonas/síntese química , Paládio/química , Catálise , Cobre/química , Ciclização , Hidrocarbonetos Aromáticos/química , Estrutura Molecular , Água/químicaRESUMO
[reaction: see text] Benzo[b]furan-3-carboxylic acid (2) was generated from 1 by forming three new bonds in one step via a Pd(II)-mediated cascade carboxylative annulation. The proposed mechanism was supported by the observation of an unusual acetylation of 1 as a side reaction together with an (18)O-labeling study.
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[reaction: see text] Two types of isoquinoline scaffolds were successfully constructed in a combinatorial format via the Ugi four-component reaction and the Pd-catalyzed intramolecular Heck reaction, starting from readily available starting materials.
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Técnicas de Química Combinatória , Isoquinolinas/síntese química , Estrutura MolecularRESUMO
The palladium/bpy-catalyzed annulation of o-alkynylphenol with various aryl halides to generate diversified 2,3-diarylbenzo[b]furan is herein described. This method provides an efficient synthetic pathway for the combinatorial synthesis of conformationally restricted 2,3-diarylbenzo[b]furan for drug discovery.
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Benzofuranos/síntese química , Técnicas de Química Combinatória , Paládio/química , Fenóis/química , Catálise , Desenho de Fármacos , Indicadores e Reagentes , Estrutura Molecular , EstereoisomerismoRESUMO
Combinatorial chemistry can be used to synthesize diversified molecules on a large scale. As with all large-scale experiments, this process requires a major investment in equipment, consumables and time. Therefore, careful design is critical. As the complexity of the libraries to be generated increases, additional considerations become important. What are the issues that should be considered when planning combinatorial chemistry projects? Which features in the design strategy are critical to consider ensuring that all of the potential products will be synthesized? How are the reactants selected to optimize product synthesis and yield? Over the last several years, through an experimental process, we have successfully developed and optimized our synthetic strategy. Our approach incorporates a number of critical components into a tightly controlled process that generates molecules with maximal structural complexity. This complexity emanates from carbon-carbon bond formation, which is extremely stable and it is reminiscent of complex natural product molecules. Our studies have illustrated that transition metal catalysts are powerful reagents that can be used to drive the synthesis of diverse small molecules from less complex starting materials. In this review, we will describe some of our recent efforts to synthesize natural product-like molecules and their derivative structures to successfully create libraries of complex molecules for drug discovery applications. Our diversity-oriented synthesis methods incorporate transition metal catalysts, as a versatile tool for creating carbon-carbon bonds and structural complexity, and the branched reaction pathway, as a method for incorporating diversity into the molecular scaffolds. We will review our combinatorial chemistry program, focusing on the decisions that we made for (1) the scaffold selection; (2) the design of a diversity oriented approach for library synthesis; (3) the incorporation of the branched reaction pathway to generate natural product-like molecules from the same starting material; and (4) the process steps that we selected for chemistry development and library generation.