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1.
Chem Soc Rev ; 49(3): 908-950, 2020 Feb 10.
Artigo em Inglês | MEDLINE | ID: mdl-31958107

RESUMO

Donor and donor-donor carbenes are two important kinds of carbenes, which have experienced tremendous growth in the past two decades. This review provides a comprehensive overview of the recent development of donor and donor-donor carbene chemistry. The development of this chemistry offers efficient protocols to construct a wide variety of C-C and C-X bonds in organic synthesis. This review is organized based on the different types of carbene precursors, including diazo compounds, hydrazones, enynones, cycloheptatrienes and cyclopropenes. The typical transformations, the reaction mechanisms, as well as their subsequent applications in the synthesis of complex natural products and bioactive molecules are discussed. Due to the rapidly increasing interest in this area, we believe that this review will provide a timely and comprehensive discussion of recent progress in donor and donor-donor carbene chemistry.


Assuntos
Metano/análogos & derivados , Compostos Azo/química , Catálise , Ciclopropanos/química , Hidrazonas/química , Metais/química , Metano/síntese química , Estrutura Molecular , Estereoisomerismo
2.
Chem Commun (Camb) ; 56(5): 695-698, 2020 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-31848532

RESUMO

In this work, a hydrazone chemistry assisted DNAzyme has been designed and constructed. The introduction of hydrazone chemistry increases the versatility of DNAzymes. With superior catalytic capability, the hydrazone chemistry assisted DNAzyme has been successfully applied for the analysis of double targets. Taking 5-hydroxymethylfurfural (HMF) and lipopolysaccharide (LPS) as samples, the hydrazone chemistry assisted DNAzyme can be used for the detection of different combinations of targets. Moreover, because hydrazone chemistry is popular in nature, this work may also provide a new insight for the development of DNAzymes and their multifunctionality.


Assuntos
DNA Catalítico/química , Hidrazonas/química , Carbocianinas/química , Catálise , Fluoresceínas/química , Corantes Fluorescentes/química , Furaldeído/análogos & derivados , Furaldeído/análise , Limite de Detecção , Lipopolissacarídeos/análise , Espectrometria de Fluorescência/métodos
3.
Chem Commun (Camb) ; 56(2): 317-320, 2019 Dec 19.
Artigo em Inglês | MEDLINE | ID: mdl-31808778

RESUMO

Abnormal vitamin B6 status, marked by deficient intracellular concentrations of pyridoxal phosphate (PLP), is classified as a direct biomarker based on its biomedical significance. However, there exist no direct methods for measuring vitamin B6 status in intact cells. Here we describe the development of a fluorogenic probe, RAB6, which shows remarkable selectivity for PLP among the B6 vitamers and other cellular aldehydes.


Assuntos
Corantes Fluorescentes/química , Hidrazonas/química , Fosfato de Piridoxal/análise , Rodaminas/química , Biomarcadores/análise , Corantes Fluorescentes/síntese química , Células HeLa , Humanos , Hidrazonas/síntese química , Microscopia de Fluorescência/métodos , Rodaminas/síntese química , Espectrometria de Fluorescência/métodos
5.
J Agric Food Chem ; 67(48): 13344-13352, 2019 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-31721573

RESUMO

A series of novel anthranilic diamide derivatives (5a-5ab) containing moieties of trifluoromethylpyridine and hydrazone was designed and synthesized. The synthesized compounds were evaluated in vivo for their activities against tobacco mosaic virus (TMV) and cucumber mosaic virus (CMV). Most of the synthesized compounds displayed good to excellent antiviral activities. The compounds 5i, 5k, 5s, 5w, 5x, and 5z had the curative activity over 65% against TMV at the concentration of 500 µg/mL, which were significantly higher than those of ningnanmycin (55.0%) and ribavirin (37.9%). Notably, the curative activity of compound 5i was up to 79.5%, with the EC50 value of 75.9 µg/mL, whereas the EC50 value of ningnanmycin was 362.4 µg/mL. The pot experiments also further demonstrated the significantly curative effect of 5i. Meanwhile, compounds 5h, 5p and 5x displayed more protective activities on TMV than that of ningnanmycin. Moreover, compounds 5a, 5e, 5f, and 5i showed inactivation activity similar to ningnanmycin at 500 µg/mL, and the EC50 value of 5e (41.5 µg/mL) was lower than ningnanmycin (50.0 µg/mL). The findings of transmission electron microscopic (TEM) indicated that the synthesized compounds exhibited strong and significant binding affinity to TMV coat protein (CP) and could obstruct the self-assembly and increment of TMV particles. Microscale thermophoresis (MST) studies on TMV-CP and CMV CP revealed that some of the active compounds, particularly 5i, exhibited a strong binding capability to TMV-CP or CMV-CP. This study revealed that anthranilic diamide derivatives containing moieties of trifluoromethylpyridine and hydrazone could be used as novel antiviral agents for controlling the plant viruses.


Assuntos
Antivirais/síntese química , Antivirais/farmacologia , Diamida/química , Hidrazonas/química , Vírus de Plantas/efeitos dos fármacos , Piridinas/química , Antivirais/química , Cucumovirus/efeitos dos fármacos , Cucumovirus/crescimento & desenvolvimento , Diamida/farmacologia , Desenho de Drogas , Hidrazonas/farmacologia , Testes de Sensibilidade Microbiana , Vírus de Plantas/crescimento & desenvolvimento , Piridinas/síntese química , Piridinas/farmacologia , Relação Estrutura-Atividade , Vírus do Mosaico do Tabaco/efeitos dos fármacos , Vírus do Mosaico do Tabaco/crescimento & desenvolvimento
6.
Analyst ; 144(21): 6422-6431, 2019 Nov 07.
Artigo em Inglês | MEDLINE | ID: mdl-31584578

RESUMO

Herein, a colorimetric sensor (L) based on a naphthyl derivative bearing hydrazone receptors was synthesized via a one-step reaction process, and its recognition properties towards biologically important anions in an acetonitrile-water mixture were investigated by naked-eye observation and UV-Vis and 1H NMR spectroscopy. The molar addition of anions, such as TBAF-, TBAOH-, TBACN- and TBAAcO-, induced a significant red shift in the charge transfer band (Δλ = 73 nm, from 337 nm to 410 nm), in agreement with visible "naked eye" detectable colorimetric activities; in addition, soaked-in-L paper strips were prepared, which could significantly discriminate cyanide (KCN) and hydroxide (NaOH) ions dissolved in tap water via the litmus test method. This study was complemented by density functional theory computations to gain more insight into the interaction between L and anions.


Assuntos
Colorimetria/métodos , Cianetos/análise , Água Potável/química , Hidróxidos/análise , Cianetos/química , Teoria da Densidade Funcional , Hidrazonas/química , Hidróxidos/química , Modelos Moleculares , Conformação Molecular , Fatores de Tempo
7.
Molecules ; 24(20)2019 Oct 21.
Artigo em Inglês | MEDLINE | ID: mdl-31640238

RESUMO

The current study was chiefly designed to examine the antiproliferative and antioxidant activities of some novel quinazolinone(thione) derivatives 6-14. The present work focused on two main points; firstly, comparing between quinazolinone and quinazolinthione derivatives. Whereas, antiproliferative (against two cell lines namely, HepG2 and MCF-7) and antioxidant (by two methods; ABTS and DPPH) activities of the investigated compounds, the best quinazolinthione derivatives were 6 and 14, which exhibited excellent potencies comparable to quinazolinone derivatives 5 and 9, respectively. Secondly, we compared the activity of four series of Schiff bases which included the quinazolinone moiety (11a-d). In addition, the antiproliferative and antioxidant activities of the compounds with various aryl aldehyde hydrazone derivatives (11a-d) analogs were studied. The compounds exhibited potency that increased with increasing electron donating group in p-position (OH > OMe > Cl) due to extended conjugated systems. Noteworthy, most of antiproliferative and antioxidant activities results for the tested compounds are consistent with the DFT calculations.


Assuntos
Antineoplásicos/síntese química , Antioxidantes/síntese química , Quinazolinonas/síntese química , Antineoplásicos/química , Antineoplásicos/farmacologia , Antioxidantes/química , Antioxidantes/farmacologia , Proliferação de Células/efeitos dos fármacos , Teoria da Densidade Funcional , Ensaios de Seleção de Medicamentos Antitumorais , Células Hep G2 , Humanos , Hidrazonas/síntese química , Hidrazonas/química , Hidrazonas/farmacologia , Células MCF-7 , Estrutura Molecular , Quinazolinonas/química , Quinazolinonas/farmacologia , Bases de Schiff/síntese química , Bases de Schiff/química , Bases de Schiff/farmacologia , Relação Estrutura-Atividade , Tionas/química
8.
Eur J Med Chem ; 184: 111742, 2019 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-31605866

RESUMO

In this work, we report the antileishmanial activity of 15 compounds based on 2-pyrimidinyl hydrazone and N-acylhydrazone derivatives, being 13 new compounds. All compounds were tested against promastigotes and Leishmania amazonensis-GFP amastigotes, as well as murine macrophages. Besides, studies about the mechanism of action of the best antileishmanial compounds and in silico physicochemical and pharmacokinetic properties were performed. Studies about the mechanism of action of representative compounds of each class showed slight differences in mode of action and both are able to cause mitochondrial depolarization and increase of intracellular ROS levels. Through computational tool and further analysis of the physicochemical and pharmacokinetic parameters, the results indicating good oral bioavailability. These results confirm the potential of 2-pyrimidinyl derivatives as lead compounds in antileishmanial drug discovery.


Assuntos
Antiprotozoários/farmacologia , Hidrazonas/farmacologia , Leishmania/efeitos dos fármacos , Leishmaniose/tratamento farmacológico , Pirimidinas/farmacologia , Animais , Antiprotozoários/síntese química , Antiprotozoários/química , Relação Dose-Resposta a Droga , Descoberta de Drogas , Hidrazonas/síntese química , Hidrazonas/química , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Estrutura Molecular , Testes de Sensibilidade Parasitária , Pirimidinas/síntese química , Pirimidinas/química , Espécies Reativas de Oxigênio/metabolismo , Relação Estrutura-Atividade
9.
Chem Biodivers ; 16(11): e1900315, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31532059

RESUMO

Here, we report the synthesis and characterization of four new aroyl-hydrazone derivatives L1 -L4 , and their structural as well as biological activities have been explored. In addition to docking with bovine serum albumin (BSA) and duplex DNA, the experimental results demonstrate the effective binding of L1 -L4 with BSA protein and calf thymus DNA (ct-DNA) which is in agreement with the docking results. Further biological activities of L1 -L4 have been examined through molecular docking with different proteins which are involved in the propagation of viral or cancer diseases. L1 shows best binding affinity with influenza A virus polymerase PB2 subunit (2VY7) with binding energy -11.42 kcal/mol and inhibition constant 4.23 nm, whereas L2 strongly bind with the hepatitis C virus NS5B polymerase (2WCX) with binding energy -10.47 kcal/mol and inhibition constant 21.06 nm. Ligand L3 binds strongly with TGF-beta receptor 1 (3FAA) and L4 with cancer-related EphA2 protein kinases (1MQB) with binding energy -10.61 kcal/mol, -10.02 kcal/mol and inhibition constant 16.67 nm and 45.41 nm, respectively. The binding energies of L1 -L4 are comparable with binding energies of their proven inhibitors. L1 , L3 and L4 can be considered as both 3FAA and 1MQB dual targeting anticancer agents, while L1 and L3 are both 2VY7 and 2WCX dual targeting antiviral agents. On the other side, L2 and L4 target only one virus related target (2WCX). Furthermore, the geometry optimizations of L1 -L4 were performed via density functional theory (DFT). Moreover, all four ligands (L1 -L4 ) were characterized by NMR, FT-IR, ESI-MS, elemental analysis and their molecular structures were validated by single crystal X-ray diffraction studies.


Assuntos
Antineoplásicos/farmacologia , Antivirais/farmacologia , DNA/antagonistas & inibidores , Desenho de Drogas , Hidrazonas/farmacologia , Simulação de Acoplamento Molecular , Soroalbumina Bovina/antagonistas & inibidores , Animais , Antineoplásicos/síntese química , Antineoplásicos/química , Antivirais/síntese química , Antivirais/química , Bovinos , Proliferação de Células/efeitos dos fármacos , Cristalografia por Raios X , DNA/química , Teoria da Densidade Funcional , Ensaios de Seleção de Medicamentos Antitumorais , Hepacivirus/efeitos dos fármacos , Hidrazonas/síntese química , Hidrazonas/química , Vírus da Influenza A/efeitos dos fármacos , Ligantes , Testes de Sensibilidade Microbiana , Estrutura Molecular , Soroalbumina Bovina/química
10.
Eur J Med Chem ; 182: 111649, 2019 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-31514018

RESUMO

(NRH):quinone oxidoreductase 2 (NQO2) is associated with various processes involved in cancer initiation and progression probably via the production of ROS during quinone metabolism. Thus, there is a need to develop inhibitors of NQO2 that are active in vitro and in vivo. As part of a strategy to achieve this we have used the 4-aminoquinoline backbone as a starting point and synthesized 21 novel analogues. The syntheses utilised p-anisidine with Meldrum's acid and trimethyl orthoacetate or trimethyl orthobenzoate to give the 4-hydrazin-quinoline scaffold, which was derivatised with aldehydes or acid chlorides to give hydrazone or hydrazide analogues, respectively. The hydrazones were the most potent inhibitors of NQO2 in cell free systems, some with low nano-molar IC50 values. Structure-activity analysis highlighted the importance of a small substituent at the 2-position of the 4-aminoquinoline ring, to reduce steric hindrance and improve engagement of the scaffold within the NQO2 active site. Cytotoxicity and NQO2-inhibitory activity in vitro was evaluated using ovarian cancer SKOV-3 and TOV-112 cells (expressing high and low levels of NQO2, respectively). Generally, the hydrazones were more toxic than hydrazide analogues and further, toxicity is unrelated to cellular NQO2 activity. Pharmacological inhibition of NQO2 in cells was measured using the toxicity of CB1954 as a surrogate end-point. Both the hydrazone and hydrazide derivatives are functionally active as inhibitors of NQO2 in the cells, but at different inhibitory potency levels. In particular, 4-((2-(6-methoxy-2-methylquinolin-4-yl)hydrazono)methyl)phenol has the greatest potency of any compound yet evaluated (53 nM), which is 50-fold lower than its toxicity IC50. This compound and some of its analogues could serve as useful pharmacological probes to determine the functional role of NQO2 in cancer development and response to therapy.


Assuntos
Aminoquinolinas/farmacologia , Descoberta de Drogas , Inibidores Enzimáticos/farmacologia , Hidrazonas/farmacologia , Quinona Redutases/antagonistas & inibidores , Aminoquinolinas/síntese química , Aminoquinolinas/química , Sobrevivência Celular/efeitos dos fármacos , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Hidrazonas/síntese química , Hidrazonas/química , Modelos Moleculares , Estrutura Molecular , Quinona Redutases/metabolismo , Relação Estrutura-Atividade , Células Tumorais Cultivadas
11.
Inorg Chem ; 58(19): 12618-12627, 2019 Oct 07.
Artigo em Inglês | MEDLINE | ID: mdl-31490063

RESUMO

The aim of this paper is to design near-infrared (NIR) Al3+ fluorescent probes based on a Schiff base to extend their applications in biological systems. By combining benzo[h]quinoline unit and salicylaldehyde acylhydrazone, we designed two new Schiff base derivatives. According to theoretical simulations on previous experimental Al3+ probes, we obtained the appropriate theoretical approaches to describe the properties of these fluorescent probes. By employing such approaches on our newly designed molecules, it is found that the new molecules have high selectivity toward Al3+ and that their corresponding Al3+ complexes can emit NIR fluorescence. As a result, they are expected to be potential NIR Al3+ fluorescent probes.


Assuntos
Aldeídos/química , Alumínio/análise , Corantes Fluorescentes/química , Hidrazonas/química , Cátions/análise , Modelos Moleculares , Bases de Schiff/química , Espectrometria de Fluorescência
12.
Future Microbiol ; 14: 981-994, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31382801

RESUMO

Aim: To evaluate the potential of three benzohydrazones (1-3), four acylhydrazones derived from isoniazid (INH-acylhydrazones) (4-7) and one hydrazone (8) as antituberculosis agents. Materials & methods: Inhibitory and bactericidal activities were determined for the reference Mycobacterium tuberculosis (Mtb) strain and clinical isolates. Cytotoxicity, drug combinations and ethidium bromide accumulation assays were also performed. Results: The tested compounds (1-8) presented excellent antituberculosis activity with surprisingly inhibitory (0.12-250 µg/ml) and bactericidal values, even against multidrug-resistant Mtb clinical isolates. Compounds showed high selectivity index, with values reaching 1833.33, and a limited spectrum of activity. Some of the compounds (2 & 8) are also great inhibitors of bacillus efflux pumps. Conclusion: Benzohydrazones and INH-acylhydrazones may be considered scaffolds for the development of new anti-Mtb drugs.


Assuntos
Antituberculosos/farmacologia , Hidrazonas/farmacologia , Isoniazida/farmacologia , Mycobacterium tuberculosis/efeitos dos fármacos , Animais , Antituberculosos/síntese química , Antituberculosos/química , Linhagem Celular Tumoral , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Etídio/metabolismo , Células HeLa , Humanos , Hidrazonas/síntese química , Hidrazonas/química , Isoniazida/síntese química , Isoniazida/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Mycobacterium tuberculosis/isolamento & purificação , Tuberculose/microbiologia , Células Vero
13.
Molecules ; 24(16)2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31416271

RESUMO

Utilizing a pharmacophore hybridization approach, we have designed and synthesized a novel series of 28 new heterobivalent ß-carbolines. The in vitro cytotoxic potential of each compound was evaluated against the five cancer cell lines (LLC, BGC-823, CT-26, Bel-7402, and MCF-7) of different origin-murine and human, with the aim of determining the potency and selectivity of the compounds. Compound 8z showed antitumor activities with half-maximal inhibitory concentration (IC50) values of 9.9 ± 0.9, 8.6 ± 1.4, 6.2 ± 2.5, 9.9 ± 0.5, and 5.7 ± 1.2 µM against the tested five cancer cell lines. Moreover, the effect of compound 8z on the angiogenesis process was investigated using a chicken chorioallantoic membrane (CAM) in vivo model. At a concentration of 5 µM, compound 8z showed a positive effect on angiogenesis. The results of this study contribute to the further elucidation of the biological regulatory role of heterobivalent ß-carbolines and provide helpful information on the development of vascular targeting antitumor drugs.


Assuntos
Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Carbolinas/síntese química , Carbolinas/farmacologia , Desenho de Drogas , Hidrazonas/química , Inibidores da Angiogênese/farmacologia , Animais , Antineoplásicos/química , Carbolinas/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Técnicas de Química Sintética , Embrião de Galinha , Ensaios de Seleção de Medicamentos Antitumorais , Humanos , Concentração Inibidora 50 , Estrutura Molecular , Neovascularização Patológica/tratamento farmacológico , Relação Estrutura-Atividade
14.
Talanta ; 205: 120102, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31450421

RESUMO

A disposable and miniaturised optical sensor based on colorimetric solid-phase extraction has been designed using poly(styrene-divinylbenzene) membrane disks modified with the colorimetric reagent pyridoxal salicyloylhydrazone to determine the aluminium concentration in aqueous solutions. The extraction of Al(III) ions by the reagent immobilised onto a disk allows the quantification directly on the adsorbent surface by a miniature portable reflectance spectrometer with an optical fibre at 434 nm. The optimisation of the sensing system was carried out by a fractional factorial design 33-1 considering the extraction pH, amount of ligand immobilised onto the disk and time of immobilisation as experimental factors. The linear dynamic range of the sensor response ranged from 0.18 to 2 mg L-1 Al(III) with a detection limit of 0.18 mg L-1 (n = 10), being the precision of 6.3% for 1 mg L-1 Al(III) (n = 10, confidence level of 95%). The proposed method was successfully applied to the analysis of aluminium in leachates from cookware, antacids and hygienic care products, as contribution to the concern about aluminium as a known systemic toxicant at high doses.


Assuntos
Alumínio/análise , Poluentes Químicos da Água/análise , Antiácidos/análise , Colorimetria/métodos , Desodorantes/análise , Contaminação de Medicamentos/prevenção & controle , Hidrazonas/química , Limite de Detecção , Poliestirenos/química , Piridoxal/análogos & derivados , Extração em Fase Sólida/instrumentação , Extração em Fase Sólida/métodos , Solventes/química , Espectrofotometria/métodos , Água/análise
15.
Molecules ; 24(13)2019 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-31261693

RESUMO

Alzheimer's disease (AD) is the most common of the degenerative brain diseases and is described together with the impairment of cognitive function. Patients with AD lose the capability to code new memories, and life conditions are extremely difficult. The development of new drugs in this area continues at a great pace. A novel series of thiazole-piperazine hybrids, aimed against Alzheimer's disease (AD), have been synthesized. The structure identification of synthesized compounds was elucidated by 1HNMR, 13C-NMR, and LCMSMS spectroscopic methods. The inhibitory potential of the synthesized compounds on cholinesterase enzymes was investigated. The compounds 3a, 3c and 3i showed significant inhibitory activity on the acetylcholinesterase (AChE) enzyme. On the other hand, none of the compounds showed significant inhibitory activity on the butyrylcholinesterase (BChE) enzyme. In addition to enzyme inhibition studies, enzyme kinetic studies were performed to observe the effects of the most active inhibitor compounds on the substrate-enzyme relationship. In addition to in vitro tests, docking studies also indicated that compound 3c potentially acts as a dual binding site AChE inhibitor.


Assuntos
Inibidores da Colinesterase/síntese química , Hidrazonas/síntese química , Tiazóis/síntese química , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Cristalografia por Raios X , Proteínas Ligadas por GPI/química , Proteínas Ligadas por GPI/metabolismo , Humanos , Hidrazonas/química , Hidrazonas/farmacologia , Simulação de Acoplamento Molecular , Estrutura Molecular , Espectroscopia de Prótons por Ressonância Magnética , Relação Estrutura-Atividade , Tiazóis/química , Tiazóis/farmacologia
16.
J Photochem Photobiol B ; 197: 111553, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31326845

RESUMO

This paper describes a novel symmetric N,N'-diethylsalicylaldehyde boranyl hydrazone (1) and its in situ-generated assemblies displaying opto-analytical capabilities for the diagnosis of nucleic acids under physiological conditions. The sensing capabilities of these unprecedented supramolecular assemblies were characterized using UV-Vis spectroscopy, fluorescence spectroscopy, 1D and 2D NMR spectroscopy, dynamic light scattering, and zeta potential measurements. Model compounds lacking boranyl units (2, 3) were prepared to correlate and evaluate the sensing mechanism. The rationally designed probe 1 displays unusual aggregation-induced emissive (AIE) properties, with an average particle size of 1096 nm exhibiting green emission upon excitation at 377 nm in pH-7.2 TRIZMA buffer. A selective switch on response toward organic PO43- accompanied through specific nano-aggregations patterns and sizes, thereby causing a significant red-shift through AIE. Exploiting such switch on in green channel behavior has allowed the monitoring of DNase I activities and polymerase chain reactions.


Assuntos
Hidrazonas/química , Ácidos Nucleicos/análise , Espectrometria de Fluorescência , Boranos/química , Desoxirribonucleases/metabolismo , Cloreto de Magnésio/química , Espectroscopia de Ressonância Magnética , Ácidos Nucleicos/metabolismo , Tamanho da Partícula , Teoria Quântica
17.
Molecules ; 24(14)2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31340543

RESUMO

Four novel isatin hydrazones containing bipyridyl fragments were synthesized as potential ON/OFF switches. Hydrazone Z-isomers exhibit high thermal stability. The characteristic photochemical reaction for all studied hydrazones is the Z-E isomerization in CHCl3. After irradiation of hydrazones 1 and 2 in dimethylformamide (DMF), the photoreaction products are tautomers. When using light with the appropriate wavelength, the photo-tautomerization reaction is reversible. In these conditions, studied hydrazones have ON/OFF switch properties. In the case of hydrazones 1 and 2, by alternating heat and light stimulation it is possible to control the isomerization process reversibly. In the presence of fluoride ions, NH hydrogen from the studied hydrazones is cleaved, and the corresponding anions are formed. The resulting anions of Z-isomers are changed to the corresponding E-isomer at room temperature.


Assuntos
2,2'-Dipiridil/química , Hidrazonas/química , Isatina/química , Clorofórmio/química , Dimetilformamida/química , Ligações de Hidrogênio , Luz , Processos Fotoquímicos , Teoria Quântica , Estereoisomerismo , Temperatura Ambiente
18.
Food Chem ; 300: 125176, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31351258

RESUMO

Mycotoxins are toxic metabolites produced by fungi or molds, which may cause serious harm to human health through polluted cereal foods. In order to measure the typical mycotoxin contaminations in wheat and corn, a surface plasmon resonance (SPR) method was established using SPR sensor chip that was fabricated based on self-assembled monolayer. The minimum detection limit of aflatoxin B1, ochratoxin A, zearalenone and deoxynivalenol were identified as 0.59 ng/mL, 1.27 ng/mL, 7.07 ng/mL and 3.26 ng/mL, respectively. The cross-reactivity for all four mycotoxins were demonstrated to be low. Moreover, the test data were compared with HPLC-MS/MS confirmatory analysis results and good agreement was found between them. In conclusion, the SPR method for simultaneously detecting four mycotoxins has been developed with high sensitivity, good linearity and specificity, which can meet the detection requirements of cereal foods.


Assuntos
Micotoxinas/análise , Ressonância de Plasmônio de Superfície/métodos , Triticum/química , Zea mays/química , Aflatoxina B1/análise , Aflatoxina B1/imunologia , Cromatografia Líquida de Alta Pressão , Reações Cruzadas , Análise de Alimentos/instrumentação , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Hidrazonas/química , Limite de Detecção , Micotoxinas/imunologia , Ocratoxinas/análise , Ocratoxinas/imunologia , Sensibilidade e Especificidade , Ressonância de Plasmônio de Superfície/instrumentação , Espectrometria de Massas em Tandem , Tricotecenos/análise , Tricotecenos/imunologia , Triticum/microbiologia , Zea mays/microbiologia , Zearalenona/análise , Zearalenona/imunologia
19.
Redox Biol ; 26: 101277, 2019 09.
Artigo em Inglês | MEDLINE | ID: mdl-31352127

RESUMO

Carbonylation is one of the most remarkable expressions of the oxidative damage to proteins and the DNPH method the most common procedure to assess protein oxidation in biological samples. The present study was elicited by two hypotheses: i) is malondialdehyde, as a reactive dicarbonyl, able to induce the formation of allysine through a Maillard-type reaction? and ii) to which extent does the attachment of MDA to proteins interfere in the assessment of protein carbonyls using the DNPH method? Human serum albumin (HSA), human hemoglobin (HEM) and ß-lactoglobulin (LAC) (5 mg/mL) were incubated with MDA (0.25 mM) for 24 h at 37 °C (HSA and HEM) or 80 °C (LAC). Results showed that MDA was unable to induce oxidative deamination of lysine residues and instead, formed stable and fluorescent adducts with proteins. Such adducts were tagged by the DNPH method, accounting for most of the protein hydrazones quantified. This interfering effect was observed in a wide range of MDA concentrations (0.05-1 mM). Being aware of its limitations, protein scientists should accurately interpret results from the DNPH method, and apply, when required, other methodologies such as chromatographic methods to detect specific primary oxidation products such as allysine.


Assuntos
Malondialdeído/farmacologia , Oxirredução/efeitos dos fármacos , Proteínas/química , Ácido 2-Aminoadípico/análogos & derivados , Ácido 2-Aminoadípico/química , Humanos , Hidrazonas/química , Redes e Vias Metabólicas , Estrutura Molecular , Carbonilação Proteica/efeitos dos fármacos
20.
Acta Pharm ; 69(2): 277-285, 2019 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-31259730

RESUMO

Aroylhydrazones 1-13 were screened for antimicrobial and antibiofilm activities in vitro. N'-(2-hydroxy-phenylmethylidene)-3-pyridinecarbohydrazide (2), N'-(5-chloro-2-hydroxyphenyl-methylidene)-3-pyridinecarbohydrazide (10), N'-(3,5-chloro-2-hydroxyphenylmethylidene)-3-pyridinecarbohydrazide (11), and N'-(2-hydroxy-5-nitrophenylmethylidene)-3-pyridinecarbohydrazide (12) showed antibacterial activity against Escherichia coli, with MIC values (in µmol mL-1) of 0.18-0.23, 0.11-0.20, 0.16-0.17 and 0.35-0.37, resp. Compounds 11 and 12, as well as N'-(2-hydroxy-3-methoxyphenylmethylidene)-3-pyridinecarbohydrazide (6) and N'-(2-hydroxy-5- methoxyphenylmethylidene)-3-pyridinecarbohydrazide (8) showed antibacterial activity against Staphylococcus aureus, with the lowest MIC values of 0.005-0.2, 0.05-0.12, 0.06-0.48 and 0.17-0.99 µmol mL-1. N'-(2-hydroxy-5-methoxyphenylmethylidene)-3-pyridinecarbohydrazide (7) showed antifungal activity against both fluconazole resistant and susceptible C. albicans strains with IC90 range of 0.18-0.1 µmol mL-1. Only compound 11 showed activity against C. albicans ATCC 10231 comparable to the activity of nystatin (the lowest MIC 4.0 ×10-2 vs. 1.7 × 10-2 µmol mL-1). Good activity regarding multi-resistant clinical strains was observed for compound 12 against MRSA strain (MIC 0.02 µmol mL-1) and compounds 2, 6 and 12 against ESBL+ E. coli MFBF 12794, with the lowest MIC for compound 12 (IC50 0.16 µmol mL-1). Anti-biofilm activity was found for compounds 2 (MBFIC 0.015-0.02 µmol mL-1 against MRSA) and 12 (MBFIC 0.013 µmol mL-1 against EBSL+ E. coli). In the case of compound 2 against MRSA biofilm formation, MBFIC values were comparable to those of gentamicin sulphate, whereas in the case of compound 12 and EBSL+ E. coli even more favourable activity compared to gentamicin was observed.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Biofilmes/efeitos dos fármacos , Hidrazonas/farmacologia , Antibacterianos/química , Antifúngicos/química , Bactérias/efeitos dos fármacos , Candida albicans/efeitos dos fármacos , Farmacorresistência Bacteriana , Farmacorresistência Fúngica , Hidrazonas/química , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade
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