Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 4.832
Filtrar
1.
Chem Commun (Camb) ; 56(14): 2147-2150, 2020 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-31970367

RESUMO

Cyclam-based antibacterial molecules (CAMs) that display potent activity against both the planktonic and stationary phase of multidrug-resistant Gram-negative bacteria were rationally designed. The optimized compound retained its activity in human plasma and eradicated preformed biofilms. It also revealed excellent potency in an ex vivo model of human corneal infections with negligible propensity of resistance development. This indicated the potential of this class of compound as a future antibacterial agent to tackle human corneal infections.


Assuntos
Antibacterianos/farmacologia , Doenças da Córnea/tratamento farmacológico , Bactérias Gram-Negativas/efeitos dos fármacos , Compostos Heterocíclicos/farmacologia , Antibacterianos/química , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Compostos Heterocíclicos/química , Humanos , Testes de Sensibilidade Microbiana
2.
Food Chem ; 313: 126128, 2020 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-31951882

RESUMO

Thermal food processing has many beneficial consequences, although it also produces some unintentional undesired effects, such as the formation of potentially mutagenic and carcinogenic substances. Among them, the formation of heterocyclic aromatic amines (HAAs) has been related to the declared carcinogenicity of processed meats. In spite of this importance, HAA formation pathways remain mostly unknown, which avoids the design of targeted procedures to inhibit HAA appearance. The objective of this review is to collect information recently appeared that allow advancing in the understanding of how these compounds are produced. Particularly, the possibility that aminoimidazoazarenes are produced similarly to PhIP is discussed, including their formation by cyclizations and oligomerizations of aldehydes and creatinine under usual cooking conditions. Present data suggest that HAA formation might be related to the pool of carbonyl compounds existing in foods, the food carbonylome, which can be controlled by carbonyl-trapping agents, such as amine and phenolic compounds.


Assuntos
Aminas/química , Análise de Alimentos , Compostos Heterocíclicos/química , Aldeídos/química , Carcinógenos/química , Creatinina/química , Ciclização , Manipulação de Alimentos/métodos
3.
Chemistry ; 26(9): 1922-1927, 2020 Feb 11.
Artigo em Inglês | MEDLINE | ID: mdl-31738451

RESUMO

The synthesis of a diverse range of heterobiaryls has been achieved by a transition-metal-free sp2 -sp2 cross-coupling strategy using lithiated heterocycle, aryl or heteroaryl boronic ester and an electrophilic halogen source. The construction of heterobiaryls was carried out through electrophilic activation of the aryl-heteroaryl boronate complex, which triggered 1,2-migration from boron to the carbon atom. Subsequent oxidation of the intermediate boronic ester afforded heterobiaryls in good yield. A comprehensive 11 B NMR study has been conducted to support the mechanism. The cross coupling between two nucleophilic cross coupling partners without transition metals reveals a reliable manifold to procure heterobiaryls in good yields. Various heterocycles like furan, thiophene, benzofuran, benzothiophene, and indole are well tolerated. Finally, we have successfully demonstrated the gram scale synthesis of the intermediates for an anticancer drug and OLED material using our methodology.


Assuntos
Ácidos Borônicos/química , Compostos Heterocíclicos/química , Catálise , Compostos Heterocíclicos/síntese química , Paládio/química , Teoria Quântica , Elementos de Transição/química
4.
Eur J Med Chem ; 186: 111908, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31791643

RESUMO

Artemisinin and its analogs have shown potent anticancer activity in primary cancer cultures and cell lines by inhibiting cancer proliferation, metastasis, and angiogenesis. Despite its apparent compatibility to normal cells and low IC50 values in comparison to the commonly used anticancer drugs, the underlying mechanisms behind their cytotoxic effects are not yet fully understood. Surprisingly, the efficacy of synthetic 1,2,4-trioxanes against cancer has not been explored yet. Given the high antitumor activity of artemisinin dimers in comparison to their monomers, we report here the synthesis of simple 1,2,3-triazole conjugated 1,2,4-trioxanes and their potential antitumor activity by studying their inhibitory effect on osteopontin (OPN) expression in MDA-MB-435 breast cancer cells. It may be noted that despite being a strong marker to identify human tumor metastasis, no study on effect of artemisinin and its synthetic and semisynthetic derivatives on OPN expression has ever been studied. Although our initial studies did not notice any straight-line relationship between the number of trioxane units in a molecule to the extent of inhibition of OPN protein expression, we could observe better results in some cases in comparison to artemisinin. We have observed that artemisinin did not show appreciable OPN downregulation in MDA-MB-435 cancer cells, but dihydroartemisinin (DHA) and some synthetic 1,2,4-trioxane monomers and dimers showed downregulation of OPN expression. Therefore, these compounds may act as an anti-metastatic agent in controlling breast cancer cells metastasis.


Assuntos
Antineoplásicos/farmacologia , Neoplasias da Mama/tratamento farmacológico , Compostos Heterocíclicos/farmacologia , Osteopontina/antagonistas & inibidores , Triazóis/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Neoplasias da Mama/metabolismo , Neoplasias da Mama/patologia , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Feminino , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Humanos , Estrutura Molecular , Osteopontina/biossíntese , Relação Estrutura-Atividade , Triazóis/síntese química , Triazóis/química
5.
Chem Rec ; 20(2): 120-141, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31250972

RESUMO

Fluorine-containing organic scaffolds are of significant interest in medicinal chemistry. The incorporation of fluorine into biomolecules can lead to remarkable changes in their physical, chemical, and biological properties. There are already many drugs on the market, which contain at least one fluorine atom. Saturated functionalized azaheterocycles as bioactive substances have gained increasing attention in pharmaceutical chemistry. Due to the high biorelevance of organofluorine molecules and the importance of N-heterocyclic compounds, selective stereocontrolled procedures to the access of new fluorine-containing saturated N-heterocycles are considered to be a hot research topic. This account summarizes the synthesis of functionalized and fluorine-containing saturated azaheterocycles starting from functionalized cycloalkenes and based on oxidative ring cleavage of diol intermediates followed by ring expansion with reductive amination.


Assuntos
Compostos Aza/química , Compostos Heterocíclicos/química , Aldeídos/química , Azepinas/síntese química , Azepinas/química , Ciclização , Flúor/química , Compostos Heterocíclicos/síntese química , Oxirredução , Estereoisomerismo
6.
Eur J Med Chem ; 186: 111888, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31787359

RESUMO

Targeting L858R/T790M/C797S mutant EGFR is a major challenge in the new-generation EGFR tyrosine kinase inhibitors development for conquering drug resistant NSCLC. In this study, a series of novel 9-heterocyclyl substituted 9H-purine derivatives were designed as EGFRL858 R/T790 M/C797S tyrosine kinase inhibitors. Among these compounds, D4, D9, D11 and D12 showed significantly potent anti-proliferation and EGFRL858 R/T790 M/C797S inhibition activity. In particular, the most potent compound D9 showed anti-proliferation against HCC827 and H1975 cell lines with the IC50 values of 0.00088 and 0.20 µM, respectively. And D9 inhibited the EGFRL858R/T790M/C797S with an IC50 value of 18 nM. Furtherly, D9 could significantly suppress the EGFR phosphorylation, induce the apoptosis, arrest cell cycle at G0/G1, and inhibit colony formation in HCC827 cell line by a concentration-dependent manner. Molecular docking indicated that the introduction of a cyclopropylsulfonamide group in D9 led to the formation of additional two hydrogen bonds with mutant Ser797 which played key roles in generating efficient EGFRL858 R/T790 M/C797S inhibitory activity. These findings strongly indicated that 9-heterocyclyl substituted 9H-purine derivatives were promising L858R/T790M/C797S mutant EGFR-TKIs. The introduction of extra hydrogen bond interaction with mutant Ser797 is efficient method for the design of the fourth-generation EGFR-TKIs.


Assuntos
Antineoplásicos/farmacologia , Descoberta de Drogas , Compostos Heterocíclicos/farmacologia , Inibidores de Proteínas Quinases/farmacologia , Purinas/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Pontos de Checagem do Ciclo Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , Receptores ErbB/metabolismo , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Humanos , Estrutura Molecular , Mutação , Inibidores de Proteínas Quinases/síntese química , Inibidores de Proteínas Quinases/química , Purinas/síntese química , Purinas/química , Relação Estrutura-Atividade
7.
J Agric Food Chem ; 68(1): 332-339, 2020 Jan 08.
Artigo em Inglês | MEDLINE | ID: mdl-31814399

RESUMO

Thermal treatment of food leads to the formation of melanoidins by reactions of carbohydrates with free amino acids or proteins in the late stage of Maillard reaction. The aim of this study was the identification of reaction mechanisms responsible for the formation of melanoidins involving active methylenes with the heterocyclic structure and the structural characterization of the resulting products. For this purpose, norfuraneol was incubated with the aldehydes pyrrole-2-aldehyde or furfural at 125 °C. With the help of high-resolution mass spectrometry, the structural composition of oligomers of up to fifteen C5-units could be described for the first time. Aldol and Michael reactions could be identified as crucial steps for the formation of new C-C-bonds. With increasing heating time, the elimination of water from the products was facilitated, and oxidation reactions of integrated reductone structures lead to the expansion of conjugated double-bond systems responsible for the color formation of the samples.


Assuntos
Aldeídos/química , Furanos/química , Compostos Heterocíclicos/química , Polímeros/química , Furaldeído/química , Reação de Maillard , Estrutura Molecular , Oxirredução
8.
Chem Pharm Bull (Tokyo) ; 67(12): 1259-1270, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31787652

RESUMO

The biary unit having heteroatom as important scaffolds widely exist in a large number of biologically active compounds and functional organic molecules. Since the cross-coupling is a useful synthetic method for constructing biaryl and heterobiaryl structures, the development of novel cross-coupling methods has been studied intensively. The oxidative biaryl coupling reaction of aromatic compounds having heteroatoms is an attractive method since they do not require the prefunctionalization of arenes. This report describes recent advances in hypervalent iodine(III) induced metal-free synthesis of biaryls having heteroatoms.


Assuntos
Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Iodo/química , Estrutura Molecular , Oxirredução
9.
Chem Pharm Bull (Tokyo) ; 67(12): 1314-1323, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31787658

RESUMO

Condensation of rhodanine (1) with pyrazol-3(2H)-one derivatives (2a-f) gave 5-substituted-2-thioxo-1,3-thiazolidin-4-one derivatives (3a-f). Reaction of compound (1) with 2-arylmethylidene-malononitrile (4a-d) yielded the unexpected derivatives (5a-d). The latter compounds were subjected to cyclization reactions with malononitrile under different basic conditions, hydroxylamine hydrochloride and/or thiourea to furnish the fused thiazole derivatives (6a-d) and (8-10a-d). Coupling of (1) with diazotized aromatic amines (11a-c) in pyridine afforded the arylhydrazones (12a-c). Fusion of latter compounds with malononitrile afforded the thiazolopyridazine derivatives (13a-c). The structures of the newly synthesized compounds were elucidated via spectral data and elemental analyses. The in-vitro cytotoxic activity of compounds (3a-f) against the cell line MCF-7 was evaluated. Also, the synthesized products were investigated for their antibacterial and antifungal activities against six standard organisms including the G+ bacteria, Staphylococcus aureus and Bacillus subtilis, G- bacteria, Escherichia coli and Proteus vulgaris in addition to fungi, Candida albicans and Aspergillus flavus.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Compostos Heterocíclicos/farmacologia , Tiazóis/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Aspergillus flavus/efeitos dos fármacos , Bacillus subtilis/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Escherichia coli/efeitos dos fármacos , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Humanos , Células MCF-7 , Testes de Sensibilidade Microbiana , Proteus vulgaris/efeitos dos fármacos , Staphylococcus aureus/efeitos dos fármacos , Tiazóis/química
10.
Top Curr Chem (Cham) ; 377(6): 35, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31720874

RESUMO

N-Heterocyclic carbene (NHC) catalysis can access umpolung reactivity of carbonyl compounds as acyl anions, enolates and homoenolates. Considerable progress has been made in asymmetric transformation by the introduction of chirality to the NHC scaffold. However, the single catalyst system has limitations in chemo-, regio- and stereoselectivity. A solution to these problems has recently emerged with the synergistic combination of NHC catalysis and metal catalysis. A number of NHC/metal combinations have been found not only to improve reactivity and stereoselectivity, but also to enable access to unprecedented transformations. This paper highlights examples of successful asymmetric NHC/metal cooperative catalysis.


Assuntos
Metais/química , Metano/análogos & derivados , Catálise , Complexos de Coordenação/química , Compostos Heterocíclicos/química , Ácidos de Lewis/química , Metano/química , Estereoisomerismo
11.
J Agric Food Chem ; 67(49): 13694-13705, 2019 Dec 11.
Artigo em Inglês | MEDLINE | ID: mdl-31756091

RESUMO

Over wood aging, matured spirits developed a complex aromatic bouquet where roasted-like notes were often perceived. Since many nitrogen heterocycles were related to these olfactory nuances, a headspace solid-phase microextraction (HS-SPME) coupled to gas chromatography-mass spectrometry was developed and validated to quantify them in both spirit and wood matrices. The various parameters affecting the extraction of the analytes from both spirit and wood samples were first investigated (i.e., fiber coating phase, dilution, pH and volume sample, adding salt, extraction time and temperature, and incubation time) to determine the best compromise for a single-run analysis of the whole set of studied compounds. Good linearity (R2 > 0.99), repeatability, reproducibility, accuracy and low detection, and quantification limits were obtained, making this analytical method a suitable tool for routine analysis of the selected nitrogen compounds. Fifteen pyrazines, three pyrroles, and three quinolines were quantified in a series of oak wood and commercial spirit samples where some of them were identified for the first time. The significant impact of some barrel features and the spirit in-wood maturation step on the N-heterocycle profile in both matrices were finally discussed.


Assuntos
Cromatografia Gasosa-Espectrometria de Massas/métodos , Compostos Heterocíclicos/química , Compostos Heterocíclicos/isolamento & purificação , Microextração em Fase Sólida/métodos , Compostos Orgânicos Voláteis/química , Compostos Orgânicos Voláteis/isolamento & purificação , Vinho/análise , Madeira/química , Odorantes/análise , Quercus/química
12.
Mini Rev Med Chem ; 19(15): 1219-1254, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31735158

RESUMO

Nowadays, heterocyclic compounds act as a scaffold and are the backbone of medicinal chemistry. Among all of the heterocyclic scaffolds, 1,4-Dihydropyridine (1,4-DHP) is one of the most important heterocyclic rings that possess prominent therapeutic effects in a very versatile manner and plays an important role in synthetic, medicinal, and bioorganic chemistry. The main aim of the study is to review and encompass relevant studies related to 1,4-DHP and excellent therapeutic benefits of its derivatives. An extensive review of Pubmed-Medline, Embase and Lancet's published articles was done to find all relevant studies on the activity of 1,4-DHP and its derivatives. 1,4-DHP is a potent Voltage-Gated Calcium Channel (VGCC) antagonist derivative which acts as an anti-hypertensive, anti- anginal, anti-tumor, anti-inflammatory, anti-tubercular, anti-cancer, anti-hyperplasia, anti-mutagenic, anti-dyslipidemic, and anti-ulcer agent. From the inferences of the study, it can be concluded that the basic nucleus, 1,4-DHP which is a voltage-gated calcium ion channel blocker, acts as a base for its derivatives that possess different important therapeutic effects. There is a need of further research of this basic nucleus as it is a multifunctional moiety, on which addition of different groups can yield a better drug for its other activities such as anti-convulsant, anti-oxidant, anti-mutagenic, and anti-microbial. This review would be significant for further researches in the development of several kinds of drugs by representing successful matrix for the medicinal agents.


Assuntos
Di-Hidropiridinas/farmacologia , Compostos Heterocíclicos/farmacologia , Neoplasias/tratamento farmacológico , Anti-Inflamatórios não Esteroides/química , Anti-Inflamatórios não Esteroides/farmacologia , Antiulcerosos/química , Antiulcerosos/farmacologia , Anti-Hipertensivos/química , Anti-Hipertensivos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Bloqueadores dos Canais de Cálcio/química , Bloqueadores dos Canais de Cálcio/farmacologia , Canais de Cálcio/metabolismo , Di-Hidropiridinas/química , Compostos Heterocíclicos/química , Úlcera/tratamento farmacológico
13.
Molecules ; 24(19)2019 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-31581424

RESUMO

A one-pot route to 2-alkyl and 2-aryl-4H-benzo[d][1,3]oxazin-4-ones (also known as 4H-3,1-benzoxazin-4-ones) has been developed and studied. The method involves the reaction of aryl-substituted anthranilic acids with orthoesters in ethanol catalyzed by acetic acid. Additionally, we have also investigated the reaction under microwave conditions. Not all of the substrates were successful in yielding the target heterocycles as some of the reactions failed to undergo the final elimination. This process led to the isolation of (±)-2-alkyl/aryl-2-ethoxy-1,2-dihydro-4H-benzo[d][1,3]oxazin-4-ones. The formation of the dihydro analogs correlated with the electron density on the aromatic ring: Electron-donating groups favored the 4H- benzo[d][1,3]oxazin-4-ones, while electron-withdrawing groups tended to favor the dihydro product. Substituting a pyridine ring for the benzene ring in the substrate acid suppressed the reaction.


Assuntos
Benzoatos/síntese química , Oxazinas/química , ortoaminobenzoatos/química , Benzoatos/química , Catálise , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Estrutura Molecular , Relação Estrutura-Atividade
14.
Molecules ; 24(19)2019 Oct 06.
Artigo em Inglês | MEDLINE | ID: mdl-31590462

RESUMO

The reaction of pyridines with trifluoroacetylated acetylenes was investigated. It was found that the reaction of various pyridines with two molecules of CF3CO-acetylenes proceeds under mild metal-free conditions. As a result, efficient stereoselective synthesis of 3-arylethynyl-3-trifluoromethyl-1,3-oxazinopyridines was elaborated. Target heterocycles can be prepared in up to quantitative yields.


Assuntos
Alquinos/química , Compostos Heterocíclicos/síntese química , Piridinas/química , Halogenação , Compostos Heterocíclicos/química , Estrutura Molecular
15.
Molecules ; 24(20)2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31640196

RESUMO

Herein, we report the synthesis of 5,12-dihydropyrazino[2,3-c:5,6-c']difuro[2,3-c:4,5-c']-diquinoline-6,14(5H,12H)diones, 2-(4-hydroxy-2-oxo-1,2-dihydroquinolin-3-yl)-1,4-diphenyl- butane-1,4-diones and 4-(benzo-[d]oxazol-2-yl)-3-hydroxy-1H-[4,5]oxazolo[3,2-a]pyridine-1-one. The new candidates were synthesized and identified by different spectroscopic techniques, and X-ray crystallography.


Assuntos
Compostos Heterocíclicos/síntese química , Quinolonas/química , Cristalografia por Raios X , Compostos Heterocíclicos/química , Hidroxiquinolinas/química , Espectroscopia de Ressonância Magnética , Estrutura Molecular
16.
Top Curr Chem (Cham) ; 377(6): 30, 2019 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-31628623

RESUMO

Ionic liquids (ILs) are considered as highly useful materials for potential diverse uses such as greener and more convenient alternatives to volatile organic solvents, reagents, additives, ligands and co-solvents. Thermal stability, negligible vapor pressure and high polarity with ionic environments have possibly conferred some unique physico-chemical properties and a wider electrochemical window on ILs. More importantly, these properties are tuneable, depending on variations in alkyl chains and counter-anions. On the other hand, various transition-metal-catalyzed cross-coupling reactions constitute an important backbone of contemporary organic synthesis. A vast number of C-C and C-heteroatom cross-coupling reactions are reported in the presence of ILs, often showing better performance. The influence of IL on the action of a given catalyst or on the course of a reaction can be relatively complex, and is not understood well enough to be able to draw succinct conclusions. However, there are a few reports in the literature that help understand the role of actual and active catalytic species stabilized in an IL environment. Stabilization, which can be either helpful or detrimental to catalysis depends on specific circumstances. This review article is aimed primarily at summarizing the various applications of ILs during the past decade, focusing as far as possible on the task-specific properties of ILs in transition-metal-catalyzed C-C and C-heteroatom cross-coupling reactions. Several successful achievements and noteworthy progress in this field of research leads to the sensible conclusion that future prospects in this field of research are not only bright but promise new horizons.


Assuntos
Líquidos Iônicos/química , Catálise , Compostos Heterocíclicos/química , Ligantes , Metano/análogos & derivados , Metano/química , Solventes/química , Elementos de Transição/química
17.
Molecules ; 24(18)2019 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-31547345

RESUMO

Three 1,4,7,10-tetraazacyclododecane-based ligands disubstituted in 1,4-positions with phosphonic acid, phosphonate monoethyl-ester, and H-phosphinic acid pendant arms, 1,4-H4do2p, 1,4-H2do2pOEt, and 1,4-H2Bn2do2pH, were synthesized and their coordination to selected metal ions, Mg(II), Ca(II), Mn(II), Zn(II), Cu(II), Eu(III), Gd(III), and Tb(III), was investigated. The solid-state structure of the phosphonate ligand, 1,4-H4do2p, was determined by single-crystal X-ray diffraction. Protonation constants of the ligands and stability constants of their complexes were obtained by potentiometry, and their values are comparable to those of previously studied analogous 1,7-disubstitued cyclen derivatives. The Gd(III) complex of 1,4-H4do2p is ~1 order of magnitude more stable than the Gd(III) complex of the 1,7-analogue, probably due to the disubstituted ethylenediamine-like structural motif in 1,4-H4do2p enabling more efficient wrapping of the metal ion. Stability of Gd(III)-1,4-H2do2pOEt and Gd(III)-H2Bn2do2pH complexes is low and the constants cannot be determined due to precipitation of the metal hydroxide. Protonations of the Cu(II), Zn(II), and Gd(III) complexes probably takes place on the coordinated phosphonate groups. Complexes of Mn(II) and alkali-earth metal ions are significantly less stable and are not formed in acidic solutions. Potential presence of water molecule(s) in the coordination spheres of the Mn(II) and Ln(III) complexes was studied by variable-temperature NMR experiments. The Mn(II) complexes of the ligands are not hydrated. The Gd(III)-1,4-H4do2p complex undergoes hydration equilibrium between mono- and bis-hydrated species. Presence of two-species equilibrium was confirmed by UV-Vis spectroscopy of the Eu(III)-1,4-H4do2p complex and hydration states were also determined by luminescence measurements of the Eu(III)/Tb(III)-1,4-H4do2p complexes.


Assuntos
Complexos de Coordenação/química , Gadolínio/química , Compostos Heterocíclicos/química , Organofosfonatos/química , Meios de Contraste , Complexos de Coordenação/síntese química , Cristalografia por Raios X , Európio/química , Ligantes , Espectroscopia de Ressonância Magnética , Manganês/química , Ácidos Fosfínicos/química , Potenciometria , Espectrofotometria Ultravioleta , Temperatura Ambiente
18.
Chem Pharm Bull (Tokyo) ; 67(9): 1015-1018, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31474724

RESUMO

Thiocyanation of aromatic compounds has been investigated using the combination of 1-chloro-1,2-benziodoxol-3-(1H)-one (1) and (trimethylsilyl)isothiocyanate (TMSNCS). The reaction with electron rich aromatic compounds proceeded smoothly to provide the thiocyanated products in high yield, while electron deficient heteroaromatic compounds were not suitable for this reaction. In these reactions, the regioselectivity was generally high. Transformations of the products were also investigated to demonstrate the utility of the reaction. Based on NMR experiments, we propose that thiocyanogen chloride is generated in situ as an active species.


Assuntos
Derivados de Benzeno/química , Compostos Heterocíclicos/química , Isotiocianatos/química , Compostos de Trimetilsilil/química , Iodo/química , Estereoisomerismo
19.
Sci Total Environ ; 697: 134052, 2019 Dec 20.
Artigo em Inglês | MEDLINE | ID: mdl-31491628

RESUMO

Three identical lab-scale sequencing batch reactors (SBR) were operated for 120 days for raw (R1), biochar (R2), and Fe(OH)3@biochar (R3) enhanced anaerobic degradation of selected nitrogen heterocyclic compounds (NHCs). The occurrence of Fe-OH ensured the successful attachment of Fe(OH)3 to biochar as evidenced by the Fourier transform infrared (FTIR) spectra of biochar and Fe(OH)3@biochar. Acute biotoxicity experiments revealed that enhancing biochar and Fe(OH)3@biochar effectively decreased the toxicity of microorganisms. Additionally, the introduction of biochar and Fe(OH)3@biochar improved the settling performance of anaerobic sludge. Further, it was concluded that enriched Longilinea and Comamonas might be the major genera that function to degrade selected NHCs in anaerobic conditions.


Assuntos
Carvão Vegetal/química , Compostos Heterocíclicos/química , Nitrogênio/química , Eliminação de Resíduos Líquidos/métodos , Anaerobiose , Biodegradação Ambiental , Reatores Biológicos , Compostos Heterocíclicos/análise , Nitrogênio/análise , Águas Residuárias
20.
Eur J Med Chem ; 181: 111562, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31377592

RESUMO

The interaction between G-Protein coupled receptor CXCR4 and its natural ligand CXCL12 has been linked to inflammation experienced by patients with Irritable Bowel Disease (IBD). Blocking this interaction could potentially reduce inflammatory symptoms in IBD patients. In this work, several thiophene-based and furan-based compounds modeled after AMD3100 and WZ811-two known antagonists that interrupt the CXCR4-CXCL12 interaction-were synthesized and analyzed. Fifteen hit compounds were identified; these compounds exhibited effective concentrations (EC) lower than 1000 nM (AMD3100) and inhibited invasion of metastatic cells by at least 45%. Selected compounds (2d, 2j, 8a) that inhibited metastatic invasion at a higher rate than WZ811 (62%) were submitted for a carrageenan inflammation test, where both 8a and 2j reduced inflammation in the same range as WZ811 (40%) but did not reduce inflammation more than 40%. Select compounds were also modeled in silico to show key residue interactions. These preliminary results with furan-based and thiophene-based analogues contribute to the new class on heterocyclic aromatic-based CXCR4 antagonists.


Assuntos
Furanos/farmacologia , Compostos Heterocíclicos/farmacologia , Inflamação/tratamento farmacológico , Receptores CXCR4/antagonistas & inibidores , Tiofenos/farmacologia , Animais , Carragenina/administração & dosagem , Linhagem Celular Tumoral , Relação Dose-Resposta a Droga , Furanos/síntese química , Furanos/química , Compostos Heterocíclicos/síntese química , Compostos Heterocíclicos/química , Membro Posterior/efeitos dos fármacos , Humanos , Inflamação/induzido quimicamente , Camundongos , Camundongos Endogâmicos C57BL , Simulação de Acoplamento Molecular , Estrutura Molecular , Receptores CXCR4/metabolismo , Relação Estrutura-Atividade , Tiofenos/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA