Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 157
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
J Org Chem ; 89(7): 4722-4732, 2024 Apr 05.
Artigo em Inglês | MEDLINE | ID: mdl-38502937

RESUMO

We report a one-step approach for the conversion of ß-enaminonitriles to synthetically versatile α-keto amides in moderate to high yields under visible light irradiation photosensitized by porphyrins. The method is mild, cost-effective, and sustainable and requires air as the sole reagent/oxidant. The reaction is believed to proceed via an ene-type pathway initiated by 1O2, followed by dehydration, imine hydrolysis, and subsequent nucleophilic substitution of the cyanide group by amine. The method offers a broad substrate scope and has also been extended for synthesis of α-keto esters with aliphatic alcohols as nucleophiles. The porphyrin recovered after the reaction can be reused multiple times.

2.
J Org Chem ; 88(13): 8600-8608, 2023 Jul 07.
Artigo em Inglês | MEDLINE | ID: mdl-37322604

RESUMO

An unprecedented C-1 selective mono-arylation/acylation of N-protected carbazoles with aryl diazonium salts/glyoxylic acids has been developed in visible light by dual catalytic system comprising of Eosin Y and palladium acetate. The methodology has good functional group tolerance and high regioselectivity and furnishes the monosubstituted products in moderate to good yields at room temperature.


Assuntos
Carbazóis , Paládio , Luz , Catálise , Acilação
3.
J Org Chem ; 87(18): 11939-11946, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36041118

RESUMO

Mild and efficient ruthenium-catalyzed hydroxy-arylation of the terminal double bond of N-substituted 3-methyleneisoindolin-1-ones is described. The reaction takes place with aryl diazonium salt as the arylating reagent and water as the hydroxyl source in visible light at ambient temperature. The strategy entails vicinal difunctionalization of alkene and enables construction of 3-benzyl-3-hydroxyisoindolin-1-one heterocyclic scaffolds in moderate to good yields. C-C and C-O bonds are formed in one pot without any external additive and oxidant through an in situ generation of a carbocation intermediate in green light.

4.
Org Biomol Chem ; 20(7): 1453-1461, 2022 02 16.
Artigo em Inglês | MEDLINE | ID: mdl-35088800

RESUMO

The directing group assisted decarboxylative ortho-benzoylation of N-aryl-7-azaindoles with α-keto acids has been achieved by synergistic visible light promoted photoredox and palladium catalysis. The approach tenders rapid entry to aryl ketone architectures from simple α-keto acid precursors via the in situ generation of a benzoyl radical intermediate. The transformation provides a range of ortho-benzoylated N-aryl-7-azaindoles, with excellent site-selectivity and good functional group compatibility under mild reaction conditions. Biological target predictions indicate that these molecules may serve as potential anti-cancer and anti-viral agents.


Assuntos
Inibidores Enzimáticos/química , Indóis/química , Paládio/química , Catálise , Descarboxilação , Inibidores Enzimáticos/farmacologia , Transcriptase Reversa do HIV/antagonistas & inibidores , Transcriptase Reversa do HIV/metabolismo , Humanos , Indóis/farmacologia , Janus Quinase 3/antagonistas & inibidores , Janus Quinase 3/metabolismo , Cetoácidos/química , Luz , Estrutura Molecular , Oxirredução , Processos Fotoquímicos , Proteínas Proto-Oncogênicas c-pim-1/antagonistas & inibidores , Proteínas Proto-Oncogênicas c-pim-1/metabolismo , Tanquirases/antagonistas & inibidores , Tanquirases/metabolismo
5.
Homeopathy ; 111(4): 261-270, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-35768003

RESUMO

OBJECTIVE: This work was undertaken to evaluate the protective effect of Arsenicum album 30C against COVID-19. DESIGN: The work was designed as a prospective parallel cluster cohort study. INTERVENTION: Participants were enrolled in a homeopathy intervention (HI) cohort (who received Arsenicum album) or in a non-intervention (NI) cohort (who received no systematic intervention) from COVID-19 containment areas of Delhi. Individuals of age 5 years or above were given four medicated pills of Arsenicum album 30C, while those from 1 to 5 years old were given two medicated pills in each dose. RESULTS: The analysis included 10,180 individuals residing in 11 COVID-19 containment areas in Delhi, out of which 6,590 individuals were in the HI cohort and 3,590 individuals were in the NI cohort. The overall protective effect of Arsenicum album 30C was 83.43% (95% confidence interval [CI], 76.77 to 88.17): 45 cases per 6,590 (8.34 per 10,000 person-weeks) in the Arsenicum album 30C group versus 143 cases per 3,590 (45.01 per 10,000 person-weeks) in the NI cohort. The protective effect of Arsenicum album 30C against laboratory confirmed COVID-19 was 74.40% (95% CI, 55.08 to 85.41): 18 cases per 6,590 (3.32 per 10,000 person-weeks) in the Arsenicum album 30C group versus 38 cases per 3,590 (11.85 per 10,000 person-weeks) in the NI cohort. CONCLUSION: The use of Arsenicum album 30C was associated with some protection against probable and laboratory-confirmed COVID-19 in a containment-zone setting. Randomized controlled trials are needed to confirm or refute these results.


Assuntos
Arsenicais , Tratamento Farmacológico da COVID-19 , COVID-19 , Homeopatia , Humanos , Pré-Escolar , Lactente , Arsenicais/uso terapêutico , Homeopatia/métodos , COVID-19/prevenção & controle , Estudos de Coortes , Estudos Prospectivos , Relação Dose-Resposta a Droga , Índia
6.
J Org Chem ; 86(1): 538-546, 2021 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-33289376

RESUMO

A unique lactonization of 2-methyl-3-acyl-4-phenylquinolines using PhIO as the oxidant and selectfluor as an additive is reported. The reaction occurs under ambient conditions through tandem oxidation and cyclization of sp3 C-H bonds under metal-free conditions. The heterocycle-fused lactones are obtained in moderate to good yield.

7.
Org Biomol Chem ; 19(20): 4585-4592, 2021 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-33955445

RESUMO

An efficient C-3 halogenation of quinolin-4-ones is reported with halogenated fluorescein dyes which serve both as a halogen source and photocatalyst. This reaction shows broad substrate scope and gives good to excellent yields of C-3 brominated/iodinated quinolones with eosin Y/rose bengal in green light under ambient conditions. The mechanistic investigations suggest a radical pathway involving the oxidative dehalogenation of the dye in the presence of air.

8.
Org Biomol Chem ; 18(15): 2921-2928, 2020 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-32239077

RESUMO

A tandem cleavage of carbon-carbon and carbon-nitrogen bonds in imidazo[1,2-a]pyridines and imidazo[1,2-a]quinolines is reported in the presence of eosin Y and visible light. The ring opening occurs under ambient conditions through singlet oxygen insertion, bond cleavage and CO2 elimination, and produces N-(pyridin-2-yl) amides and N-(quinolin-2-yl) amides in high yields. The reaction shows good versatility, and does not require strong external oxidants and additives.

9.
Org Biomol Chem ; 18(13): 2492-2500, 2020 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-32186577

RESUMO

1,3-Bis(1-alkyl-1H-indol-3-yl)benzene derivatives have been synthesized through a Zn(OTf)2 catalyzed reaction between cyclohexanones and indoles. Cyclohexanones act as an aryl source via an alkylation-dehydrogenation-aromatization sequence, and undergo regioselective C-C bond formation with indoles at the 1,3-position. A useful library of these derivatives obtained in moderate to high yields has been prepared and a tentative mechanism has been proposed based upon GCMS analysis and time dependent NMR studies.

10.
J Immunol ; 200(3): 1188-1197, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-29282312

RESUMO

Exaggerated inflammatory responses during influenza A virus (IAV) infection are typically associated with severe disease. Neutrophils are among the immune cells that can drive this excessive and detrimental inflammation. In moderation, however, neutrophils are necessary for optimal viral control. In this study, we explore the role of the nucleotide-binding domain leucine-rich repeat containing receptor family member Nlrp12 in modulating neutrophilic responses during lethal IAV infection. Nlrp12-/- mice are protected from lethality during IAV infection and show decreased vascular permeability, fewer pulmonary neutrophils, and a reduction in levels of neutrophil chemoattractant CXCL1 in their lungs compared with wild-type mice. Nlrp12-/- neutrophils and dendritic cells within the IAV-infected lungs produce less CXCL1 than their wild-type counterparts. Decreased CXCL1 production by Nlrp12-/- dendritic cells was not due to a difference in CXCL1 protein stability, but instead to a decrease in Cxcl1 mRNA stability. Together, these data demonstrate a previously unappreciated role for Nlrp12 in exacerbating the pathogenesis of IAV infection through the regulation of CXCL1-mediated neutrophilic responses.


Assuntos
Quimiocina CXCL1/metabolismo , Vírus da Influenza A/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/genética , Infiltração de Neutrófilos/imunologia , Neutrófilos/imunologia , Infecções por Orthomyxoviridae/imunologia , Animais , Permeabilidade Capilar/genética , Quimiocina CXCL1/genética , Células Dendríticas/imunologia , Feminino , Pulmão/imunologia , Pulmão/patologia , Pulmão/virologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Knockout , Infecções por Orthomyxoviridae/mortalidade , Infecções por Orthomyxoviridae/virologia , Estabilidade de RNA/genética , RNA Mensageiro/genética
11.
J Anaesthesiol Clin Pharmacol ; 36(4): 443-449, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33840921

RESUMO

Pott's disease is the most common granulomatous spine infection caused by tubercle bacilli and is a common site of osseous tuberculosis, accounting for 50-60% of cases. The delay in establishing diagnosis and management results in complications such as spinal cord compression and spinal deformity. The aim of this narrative review is to discuss the perioperative concerns in patients for spine surgery. The literature source for this review was obtained via PubMed, Medline, Google Scholar, Cochrane database of systematic reviews, and textbooks until December 2019. On the literature search, we could not retrieve any review article specifically discussing the perioperative concerns of spinal tuberculosis. Therefore, the aim of the present narrative review is to discuss the perioperative concerns of patients for spine surgery along with the specific concerns related to spinal tuberculosis.

12.
J Org Chem ; 84(15): 9661-9670, 2019 Aug 02.
Artigo em Inglês | MEDLINE | ID: mdl-31267751

RESUMO

An unprecedented synthesis of fused quinazolinones from N-pyridylindoles under oxidative conditions using a combination of (diacetoxyiodo)benzene and K2S2O8 is reported. The reaction is metal-free, has a broad substrate scope, is operationally simple with short reaction time, and provides 11H-pyrido[2,1-b]quinazolin-11-one derivatives in moderate to high yields. It is believed to proceed via an in situ generated 2-hydroxy-1-(pyridin-2-yl)indolin-3-one as the key reaction intermediate, which undergoes a C-C bond cleavage to produce an electrophilic C-3 site in N-pyridyl indole. Subsequent nucleophilic attack by pyridyl nitrogen results in its cyclization.

13.
J Org Chem ; 84(20): 13045-13052, 2019 Oct 18.
Artigo em Inglês | MEDLINE | ID: mdl-31535546

RESUMO

Copper acetate mediated regioselective ortho-arylthiolation of 2-arylpyridines has been accomplished for the first time using S-aryl arenesulfonothioate as the arylthiolating agent. The reaction shows good functional group tolerance and gives thioarylated products in 67-89% yields. This reagent is a good alternative to unpleasant smelling arylthiols. Experimental evidence suggests an unprecedented insertion of an arylthio unit from both parts of the reagent (SPh and p-TolSO2) in the presence of copper acetate. Indoles and imidazopyridines also undergo facile reaction at the C-3 position and furnish thioarylated derivatives in good yields.

14.
J Indian Assoc Pediatr Surg ; 24(1): 72-74, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30686893

RESUMO

Duplication cyst is a rare congenital malformation. Enterogenous cyst are foregut duplication cyst with or without a vertebral defect. We report a case of a 36hr old neonate with mediastinal enterogenous cyst associated with vertebral defects. The embryology, differentials, and management of enterogenous cyst in the newborn have been discussed.

15.
J Org Chem ; 83(6): 3226-3235, 2018 03 16.
Artigo em Inglês | MEDLINE | ID: mdl-29463081

RESUMO

Copper chalcogenide nanoparticles (Cu2S) synthesized for the first time from a single-source precursor, CuSPh, act as highly efficient and reusable heterogeneous catalyst for regioselective amination of N, N-dimethylbenzylamines with various azoles. The reaction involves N-H/C-H cross-dehydrogenative coupling (CDC) and demonstrates wide functional group tolerance. It provides highly selective access to N1-alkylated benzotriazoles, N2-alkylated 1,2,3-triazoles and 4-phenyl-1,2,3-triazoles, and N-alkylated carbazoles in 70-89% yields under solvent-free conditions. The Cu2S nanocatalyst has been characterized by PXRD, XPS, SEM-EDX, and HR-TEM analysis. Mechanistic studies suggest that the reaction follows a radical pathway and involves an iminium ion intermediate.

16.
Br J Nutr ; 120(10): 1189-1200, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30401000

RESUMO

Dementia is a leading cause of morbidity and mortality without pharmacologic prevention or cure. Mounting evidence suggests that adherence to a Mediterranean dietary pattern may slow cognitive decline, and is important to characterise in at-risk cohorts. Thus, we determined the reliability and validity of the Mediterranean Diet and Culinary Index (MediCul), a new tool, among community-dwelling individuals with mild cognitive impairment (MCI). A total of sixty-eight participants (66 % female) aged 75·9 (sd 6·6) years, from the Study of Mental and Resistance Training study MCI cohort, completed the fifty-item MediCul at two time points, followed by a 3-d food record (FR). MediCul test-retest reliability was assessed using intra-class correlation coefficients (ICC), Bland-Altman plots and κ agreement within seventeen dietary element categories. Validity was assessed against the FR using the Bland-Altman method and nutrient trends across MediCul score tertiles. The mean MediCul score was 54·6/100·0, with few participants reaching thresholds for key Mediterranean foods. MediCul had very good test-retest reliability (ICC=0·93, 95 % CI 0·884, 0·954, P<0·0001) with fair-to-almost-perfect agreement for classifying elements within the same category. Validity was moderate with no systematic bias between methods of measurement, according to the regression coefficient (y=-2·30+0·17x) (95 % CI -0·027, 0·358; P=0·091). MediCul over-estimated the mean FR score by 6 %, with limits of agreement being under- and over-estimated by 11 and 23 %, respectively. Nutrient trends were significantly associated with increased MediCul scoring, consistent with a Mediterranean pattern. MediCul provides reliable and moderately valid information about Mediterranean diet adherence among older individuals with MCI, with potential application in future studies assessing relationships between diet and cognitive function.


Assuntos
Disfunção Cognitiva/prevenção & controle , Disfunção Cognitiva/fisiopatologia , Dieta Mediterrânea , Comportamento Alimentar , Avaliação Nutricional , Inquéritos e Questionários , Idoso , Austrália , Cognição , Demência/prevenção & controle , Dieta , Registros de Dieta , Feminino , Alimentos , Humanos , Masculino , Pessoa de Meia-Idade , Ensaios Clínicos Controlados Aleatórios como Assunto , Reprodutibilidade dos Testes
17.
Clin Exp Nephrol ; 22(3): 508-516, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29022109

RESUMO

BACKGROUND: The induction of CD80 on podocytes has been shown in animal models of podocyte injury and in certain cases of nephrotic syndrome. In a lipopolysaccharide (LPS)-induced mouse model of albuminuria, we have recently shown a signalling axis of LPS-myeloid cell activation-TNFα production-podocyte CD80 induction-albuminuria. Therefore, in this report, we investigated the cellular and molecular consequences of TNFα addition and CD80 expression on cultured podocytes. METHODS: A murine podocyte cell line was used for TNFα treatment and for over-expressing CD80. Expression and localization of various podocyte proteins was analysed by reverse transcriptase-polymerase chain reaction, western blotting and immunofluorescence. HEK293 cells were used to biochemically characterize interactions. RESULTS: Podocytes treated with LPS in vitro did not cause CD80 upregulation but TNFα treatment was associated with an increase in CD80 levels, actin derangement and poor wound healing. Podocytes stably expressing CD80 showed actin derangement and co-localization with Neph1. CD80 and Neph1 interaction was confirmed by pull down assays of CD80 and Neph1 transfected in HEK293 cells. CONCLUSION: Addition of TNFα to podocytes causes CD80 upregulation, actin reorganization and podocyte injury. Overexpressed CD80 and Neph1 interact via their extracellular domain. This interaction implies a mechanism of slit diaphragm disruption and possible use of small molecules that disrupt CD80-Neph1 interaction as a potential for treatment of nephrotic syndrome associated with CD80 upregulation.


Assuntos
Antígeno B7-1/metabolismo , Proteínas de Membrana/metabolismo , Síndrome Nefrótica/etiologia , Podócitos/fisiologia , Fator de Necrose Tumoral alfa/fisiologia , Actinas/metabolismo , Animais , Linhagem Celular , Células HEK293 , Humanos , Camundongos
18.
J Org Chem ; 82(9): 4784-4792, 2017 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-28406031

RESUMO

A metal-free cross-dehydrogenative coupling between quinoxalinones (sp2 C-H) and amines (N-H) in the presence of catalytic iodine is reported. The reaction yields 3-aminoquinoxalinones in moderate to high yields under ambient conditions in dioxane as solvent and aqueous tert-butyl hydroperoxide (TBHP) as the terminal oxidant. The reaction is highly versatile and exhibits good functional group tolerance with a range of primary and secondary amines. It provides a practical access to pharmaceutically active 3-aminoquinoxalinone derivatives. Preliminary mechanistic studies reveal in situ iodination of the amine as the putative mode of activation.

19.
J Org Chem ; 82(2): 1105-1113, 2017 01 20.
Artigo em Inglês | MEDLINE | ID: mdl-28001401

RESUMO

We describe a modular, palladium catalyzed synthesis of aryl(hetero)aryl benzophenones and aryl benzoates from aryl(hetero)aryl halides using CHCl3 as the carbonyl source in the presence of KOH. The reaction occurs in tandem through an initial carbonylation to generate an aroyl halide, which undergoes coupling with arylboronic acids, bornonates, and phenols. Direct carbonylative coupling of indoles at the third position has also been accomplished under slightly modified reaction conditions by in situ activation of the C-H bond. Notably, CHCl3 is a convenient and safe alternation of CO gas, provides milder reaction conditions with high functional group tolerance, and gives the products in moderate to good yields.

20.
AJR Am J Roentgenol ; 209(6): 1297-1301, 2017 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-28898128

RESUMO

OBJECTIVE: Radiologic technologists may repeat images within a radiographic examination because of perceived suboptimal image quality, excluding these original images from submission to a PACS. This study assesses the appropriateness of technologists' decisions to repeat musculoskeletal and chest radiographs as well as the utility of repeat radiographs in addressing examinations' clinical indication. MATERIALS AND METHODS: We included 95 musculoskeletal and 87 chest radiographic examinations in which the technologist repeated one or more images because of perceived image quality issues, rejecting original images from PACS submission. Rejected images were retrieved from the radiograph unit and uploaded for viewing on a dedicated server. Musculoskeletal and chest radiologists reviewed rejected and repeat images in their timed sequence, in addition to the studies' remaining images. Radiologists answered questions regarding the added value of repeat images. RESULTS: The reviewing radiologist agreed with the reason for rejection for 64.2% of musculoskeletal and 60.9% of chest radiographs. For 77.9% and 93.1% of rejected radiographs, the clinical inquiry could have been satisfied without repeating the image. For 75.8% and 64.4%, the repeated images showed improved image quality. Only 28.4% and 3.4% of repeated images were considered to provide additional information that was helpful in addressing the clinical question. CONCLUSION: Most repeated radiographs (chest more so than musculoskeletal radiographs) did not add significant clinical information or alter diagnosis, although they did increase radiation exposure. The decision to repeat images should be made after viewing the questionable image in context with all images in a study and might best be made by a radiologist rather than the performing technologist.


Assuntos
Doenças Musculoesqueléticas/diagnóstico por imagem , Controle de Qualidade , Radiografia Torácica/normas , Radiologistas , Tomada de Decisões , Humanos , Variações Dependentes do Observador , Retratamento
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA