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1.
Molecules ; 26(5)2021 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-33669147

RESUMO

An aniline-functionalized naphthalene dialdehyde Schiff base fluorescent probe L with aggregation-induced enhanced emission (AIEE) characteristics was synthesized via a simple one-step condensation reaction and exhibited excellent sensitivity and selectivity towards copper(II) ions in aqueous media with a fluorescence " turn-off " phenomenon. The detection limit of the probe is 1.64 × 10-8 mol·L-1. Furthermore, according to the results of the UV-vis/fluorescence titrations, Job's plot method and 1H-NMR titrations, a 1:2 stoichiometry was identified. The binding constant between L and Cu2+ was calculated to be Ka = 1.222 × 103. In addition, the AIEE fluorescent probe L could be applied to detection in real water samples with satisfactory recoveries in the range 99.10-102.90% in lake water and 98.49-102.37% in tap water.


Assuntos
Cobre/análise , Corantes Fluorescentes/química , Naftalenos/química , Poluentes Químicos da Água/análise , Cristalografia por Raios X , Corantes Fluorescentes/síntese química , Íons/análise , Modelos Moleculares , Estrutura Molecular , Naftalenos/síntese química , Bases de Schiff/síntese química , Bases de Schiff/química
2.
ACS Appl Mater Interfaces ; 13(7): 9006-9014, 2021 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-33576614

RESUMO

The development and application of natural antibacterial materials have always been the focus of biomedical research. Borneol as a natural antibacterial compound has received extensive attention. However, the hydrophobicity caused by its unique structure limits its application range to a certain extent. In this study, we combine zwitterionic 2-methacryloyloxyethyl phosphorylcholine (MPC) with a complex bicyclic monoterpene structure borneol compound and prepare an excellent antifouling and antibacterial surface via the Schiff-base bond. The prepared coating has excellent hydrophilicity verified by the contact angle (CA), and its polymer layer is confirmed by X-ray photoelectron spectroscopy (XPS). The zwitterion MPC and borneol moieties in the copolymer play a coordinating role, relying on super hydration and the special stereochemical structure to prevent protein adsorption and inhibit bacterial adhesion, respectively, which are demonstrated by bovine serum albumin (BSA) adsorption and antibacterial activity test. Moreover, the water-soluble borneol derivative as the antibacterial surfaces we designed here was biocompatible toward MRC-5 (lung fibroblasts), as showed by in vitro cytotoxicity assays. Such results indicate the potential application of the as-prepared hydrophilic surfaces in the biomedical materials.


Assuntos
Antibacterianos/farmacologia , Incrustação Biológica/prevenção & controle , Canfanos/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Metacrilatos/farmacologia , Fosforilcolina/análogos & derivados , Polímeros/farmacologia , Adsorção , Antibacterianos/síntese química , Antibacterianos/química , Canfanos/química , Sobrevivência Celular/efeitos dos fármacos , Materiais Revestidos Biocompatíveis/síntese química , Materiais Revestidos Biocompatíveis/química , Escherichia coli/efeitos dos fármacos , Humanos , Metacrilatos/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Tamanho da Partícula , Fosforilcolina/química , Fosforilcolina/farmacologia , Polímeros/síntese química , Polímeros/química , Bases de Schiff/síntese química , Bases de Schiff/química , Bases de Schiff/farmacologia , Soroalbumina Bovina/química , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície
3.
Int J Nanomedicine ; 15: 2583-2603, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32368042

RESUMO

Introduction: Over the past several years, nano-based therapeutics were an effective cancer drug candidate in order to overcome the persistence of deadliest diseases and prevalence of multiple drug resistance (MDR). Methods: The main objective of our program was to design organosilane-modified Fe3O4/SiO2/APTS(~NH2) core magnetic nanocomposites with functionalized copper-Schiff base complex through the use of (3-aminopropyl)triethoxysilane linker as chemotherapeutics to cancer cells. The nanoparticles were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD), field emission scanning electron microscopy (FE-SEM), TEM, and vibrating sample magnetometer (VSM) techniques. All analyses corroborated the successful synthesis of the nanoparticles. In the second step, all compounds of magnetic nanoparticles were validated as antitumor drugs through the conventional MTT assay against K562 (myelogenous leukemia cancer) and apoptosis study by Annexin V/PI and AO/EB. The molecular dynamic simulations of nanoparticles were further carried out; afterwards, the optimization was performed using MM+, semi-empirical (AM1) and Ab Initio (STO-3G), ForciteGemo Opt, Forcite Dynamics, Forcite Energy and CASTEP in Materials studio 2017. Results: The results showed that the anti-cancer activity was barely reduced after modifying the surface of the Fe3O4/SiO2/APTS nanoparticles with 2-hydroxy-3-methoxybenzaldehyde as Schiff base and then Cu(II) complex. The apoptosis study by Annexin V/PI and AO/EB stained cell nuclei was performed that apoptosis percentage of the nanoparticles increased upon increasing the thickness of Fe3O4 shell on the magnetite core. The docking studies of the synthesized compounds were conducted towards the DNA and Topoisomerase II via AutoDock 1.5.6 (The Scripps Research Institute, La Jolla, CA, USA). Conclusion: Results of biology activities and computational modeling demonstrate that nanoparticles were targeted drug delivery system in cancer treatment.


Assuntos
Cobre/química , Compostos Férricos/síntese química , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Propilaminas/síntese química , Bases de Schiff/síntese química , Silanos/síntese química , Dióxido de Silício/síntese química , Apoptose , Núcleo Celular/metabolismo , DNA/química , DNA Topoisomerases Tipo II/química , Compostos Férricos/química , Humanos , Células K562 , Magnetismo , Nanopartículas de Magnetita/química , Nanopartículas de Magnetita/ultraestrutura , Propilaminas/química , Bases de Schiff/química , Silanos/química , Dióxido de Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Difração de Raios X
5.
Amino Acids ; 52(3): 397-407, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31932980

RESUMO

Schiff bases represent a class of molecules widely studied for their importance in organic and coordination chemistry. Despite the large amount of studies on the chemical and biological properties of the Schiff bases, the different experimental conditions prevent a useful comparison to search for a correlation structure-activity. Moreover, literature is lacking in comprehensive data on the spectroscopic characterization of these compounds. For this reason, six Schiff bases, derived from salicylaldehyde and natural amino acids were fully characterized by nuclear magnetic resonance and infrared spectroscopy, and their aqueous solution equilibria, antiproliferative activity and DNA-binding activity were examined. All experimental conditions were kept constants to achieve comparable information and useful insights about their structure-activity correlation. The synthesized compounds showed DNA binding constants in the 101-102 M-1 range, depending on the substituent present in the amino acid side-chain, and resulted devoid of significant cytotoxic activity against the different human tumor cell lines showing IC50 values higher than 100 µM.


Assuntos
Aldeídos/química , Aminoácidos/síntese química , Antineoplásicos/síntese química , Antineoplásicos/farmacologia , Bases de Schiff/síntese química , Bases de Schiff/farmacologia , Linhagem Celular Tumoral , Humanos , Hidrogenação , Concentração Inibidora 50 , Espectroscopia de Ressonância Magnética , Espectrofotometria Infravermelho
6.
Int J Biol Macromol ; 147: 534-546, 2020 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-31935406

RESUMO

Several possible configurations (CS/NI1-10) for the surface adsorption of 5-nitroisatin (NI) on the chitosan polymer (CS) were investigated using quantum mechanical methods in the gas and solution phases. The values of the binding energies indicate the energetic stability of these configurations. The solvation energies demonstrate that the solubility of NI and CS increases in the presence of each other. The role of hydrogen bonds in noncovalent surface functionalization was determined by AIM analysis. The mechanism of covalent surface functionalization and the explicit solvent effects (methanol) in this mechanism were investigated and it was determined that the covalent functionalization through Schiff base formation is possible. These findings, in addition to the biological applications of the chitosan Schiff bases and their complexes, led us to synthesize a new Schiff base from condensation reaction of CS and NI (CSB) together with its Ni(II) and Cu(II) complexes. The synthesized compounds were characterized by the elemental analysis, infrared spectroscopy (IR), thermogravimetry analysis (TGA) and differential scanning calorimetry (DSC). Also, optimized geometries, assignment of the IR vibrational bands as well as exploring of the frontier orbitals of the synthesized compounds have been calculated using density functional levels of theory.


Assuntos
Quitosana/química , Complexos de Coordenação , Cobre/química , Níquel/química , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Bases de Schiff/síntese química , Bases de Schiff/química
7.
Int J Mol Sci ; 21(2)2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31952278

RESUMO

Even 155 years after their first synthesis, Schiff bases continue to surprise inorganic chemists. Schiff-base ligands have played a major role in the development of modern coordination chemistry because of their relevance to a number of interdisciplinary research fields. The chemistry, properties and applications of transition metal and lanthanoid complexes with Schiff-base ligands are now quite mature. On the contrary, the coordination chemistry of Schiff bases with actinoid (5f-metal) ions is an emerging area, and impressive research discoveries have appeared in the last 10 years or so. The chemistry of actinoid ions continues to attract the intense interest of many inorganic groups around the world. Important scientific challenges are the understanding the basic chemistry associated with handling and recycling of nuclear materials; investigating the redox properties of these elements and the formation of complexes with unusual metal oxidation states; discovering materials for the recovery of trans-{UVIO2}2+ from the oceans; elucidating and manipulating actinoid-element multiple bonds; discovering methods to carry out multi-electron reactions; and improving the 5f-metal ions' potential for activation of small molecules. The study of 5f-metal complexes with Schiff-base ligands is a currently "hot" topic for a variety of reasons, including issues of synthetic inorganic chemistry, metalosupramolecular chemistry, homogeneous catalysis, separation strategies for nuclear fuel processing and nuclear waste management, bioinorganic and environmental chemistry, materials chemistry and theoretical chemistry. This almost-comprehensive review, covers aspects of synthetic chemistry, reactivity and the properties of dinuclear and oligonuclear actinoid complexes based on Schiff-base ligands. Our work focuses on the significant advances that have occurred since 2000, with special attention on recent developments. The review is divided into eight sections (chapters). After an introductory section describing the organization of the scientific information, Sections 2 and 3 deal with general information about Schiff bases and their coordination chemistry, and the chemistry of actinoids, respectively. Section 4 highlights the relevance of Schiff bases to actinoid chemistry. Sections 5-7 are the "main menu" of the scientific meal of this review. The discussion is arranged according the actinoid (only for Np, Th and U are Schiff-base complexes known). Sections 5 and 7 are further arranged into parts according to the oxidation states of Np and U, respectively, because the coordination chemistry of these metals is very much dependent on their oxidation state. In Section 8, some concluding comments are presented and a brief prognosis for the future is attempted.


Assuntos
Elementos da Série Actinoide/química , Complexos de Coordenação/química , Modelos Químicos , Bases de Schiff/química , Catálise , Técnicas de Química Sintética/métodos , Técnicas de Química Sintética/tendências , Complexos de Coordenação/síntese química , Ligantes , Estrutura Molecular , Oxirredução , Bases de Schiff/síntese química
8.
Int J Biol Macromol ; 143: 714-723, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31726150

RESUMO

In this study, the structure of inulin was chemically modified by Schiff bases in order to improve its biological activity. A total of 6 kinds of inulin derivatives were synthesized according to aza-Wittig reaction. Their structures were confirmed by FTIR, 1H NMR, and 13C NMR spectroscopy. The antioxidant activity of the inulin derivatives was evaluated in vitro. Their antifungal activities against three kinds of plant pathogenic fungi, including Botrytis cinerea, Fusarium oxysporum f. sp. cucumerium Owen, and Phomopsis asparagi, were also studied. The results showed that the biological activities of the derivatives were significantly improved compared to pure inulin. 3HBSAIL could completely scavenge hydroxyl radical and DPPH radical at 1.6mgmL-1. 3,4DHBSAIL and 2,3,4THBSAIL exhibited strong antioxidant activity as far as the four tested antioxidant systems. Moreover, the scavenging rates of 3,4DHBSAIL and 2,3,4THBSAIL against DPPH radicals were both 100% even at the lowest test concentration (0.1mgmL-1). The synthetic inulin derivatives showed a broad antifungal spectrum against the tested fungi. At 1.6mgmL-1, the inhibitory rates of 3HBSAIL against Botrytis cinerea, Fusarium oxysporum f. sp. cucumerium Owen, and Phomopsis asparagi were 93%, 83%, and 82%, respectively. The biological activities of the inulin derivatives were closely related to the DS, the number of phenolic hydroxyl groups and their substitutive positions. The products described in this paper have great potential as biomaterials with good bioactivity and biocompatibility.


Assuntos
Antifúngicos/farmacologia , Antioxidantes/farmacologia , Inulina/química , Bases de Schiff/síntese química , Compostos de Bifenilo/química , Espectroscopia de Ressonância Magnética Nuclear de Carbono-13 , Depuradores de Radicais Livres/química , Fungos/efeitos dos fármacos , Radical Hidroxila/química , Inulina/síntese química , Testes de Sensibilidade Microbiana , Picratos/química , Espectroscopia de Prótons por Ressonância Magnética , Bases de Schiff/química , Solubilidade , Espectroscopia de Infravermelho com Transformada de Fourier , Água
9.
Anal Chim Acta ; 1095: 185-196, 2020 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-31864621

RESUMO

A multiple turn-on fluorophore (FHCS), combining fluorescein, hydrazone, cyanuric chloride and salicylaldehyde chromone into a molecule, was identified and developed based on density functional theoretical calculation. It was expected that FHCS could express exclusive fluorescent signals and improved Stokes shifts when chelating Al3+ or Zn2+. After it was synthesized and characterized in detail, it was noted that FHCS could turn-on fluorescently discriminate trace Al3+ and Zn2+ under the optimized conditions, i.e., from no-fluorescence to strong blue fluorescence for Al3+ and to green fluorescence for Zn2+ with low detection limits of 5.37 × 10-8 M and 7.90 × 10-8 M respectively. Owing to its low toxicity, FHCS was successfully applied for quantitative determination of Al3+ and Zn2+ in natural aqueous samples and toxicity evaluation of Al3+ and Zn2+ in living cells and bio-tissues with excellent linear relationships. The action mechanisms for FHCS with Al3+ and Zn2+ were confirmed to form stable 5-member-co-6-member condensed rings between Al3+/Zn2+ and N/O atoms in FHCS by both theoretic and experimental methods, which resulted in turn-on fluorescence with different dipolar moments and improved Stokes shifts.


Assuntos
Alumínio/análise , Fluoresceínas/química , Corantes Fluorescentes/química , Zinco/análise , Animais , Teoria da Densidade Funcional , Desenho de Fármacos , Fluoresceínas/síntese química , Fluoresceínas/toxicidade , Corantes Fluorescentes/síntese química , Corantes Fluorescentes/toxicidade , Células HeLa , Humanos , Limite de Detecção , Camundongos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Modelos Químicos , Imagem Óptica/métodos , Bases de Schiff/síntese química , Bases de Schiff/química , Bases de Schiff/toxicidade , Espectrometria de Fluorescência/métodos , Águas Residuárias/análise , Poluentes Químicos da Água/análise
10.
J Microencapsul ; 37(1): 29-40, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31718349

RESUMO

A heterostructured Schiff base ligand (Benzildiethylenetriamine)-Silver-Guar gum encapsulated nanocomposites was intended to prepare by simple sonication assisted reflux method. Appropriate composition of purified guar gum, Schiff base ligand and silver nitrate were used for the synthesis. The synthesised nanocomposites were characterised by photoluminescence spectrum, UV-vis diffuse reflectance spectrophotometer, Fourier transform infra-red spectroscopy, X-ray diffractometer, scanning electron microscopy and transmission electron microscopy. The crystalline peaks of XRD and FTIR reveals that Schiff base ligand and guar gum forms metal-organic matrix. Morphology studies have confirmed the organic framework structure and metallic silver nanoparticles are embedded on the organic framework. The efficiency of nanocomposites depends on adsorption capacity and silver nanoparticles that are encapsulated thereby increasing the visible light absorption through surface plasma resonance. The nanocomposite was proved to be highly selective in hydrogenation reaction which favoured the formation of aniline from nitrobenzene as single product with short reaction time and 90% conversion.


Assuntos
Galactanos/química , Mananas/química , Nanocompostos/química , Gomas Vegetais/química , Bases de Schiff/química , Prata/química , Compostos de Anilina/química , Catálise , Técnicas de Química Sintética , Galactanos/síntese química , Hidrogenação , Luz , Mananas/síntese química , Nanocompostos/ultraestrutura , Nanotecnologia , Nitrobenzenos/química , Gomas Vegetais/síntese química , Bases de Schiff/síntese química , Sonicação
11.
Eur J Med Chem ; 185: 111780, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31655429

RESUMO

Two new series of pyrrolizine-5-carboxamides were synthesized and evaluated for their anticancer and anti-inflammatory activities. The new compounds exhibited potent cytotoxicity (IC50 = 0.10-22.96 µM) against three cancer (MCF-7, A2780 and HT29) cell lines with selectivity index in the range of 1-258. Moreover, these compounds also exhibited significant anti-inflammatory activity (18.13-44.51% inhibition of inflammation) mediated by inhibition of COX-1/2 with preferential inhibition of COX-2. The study of SAR revealed favorable cytotoxic outcomes of the aliphatic side chain and 4-thiazolidinone moiety at C6 of the pyrrolizine nucleus, while anti-inflammatory activities was improved with the (hetero)aromatic substituents. The IC50 values which inhibit COX-2 were higher than those needed to inhibit the growth of cancer cell lines. Mechanistic studies also revealed inhibition of multiple kinases by compounds 12, 19 and 22. Moreover, compounds 12, 14, 16 and 22 induced cell cycle arrest and apoptosis in MCF-7 cells. Docking studies revealed nice fitting of the new compounds into COX-1/2. Additionally, compounds 12, 19 and 22 also exhibited higher affinity for CDK2 than CAN508. To sum up, the above-mentioned data highlight these compounds as promising anti-inflammatory and anticancer agents.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Antineoplásicos/farmacologia , Inibidores de Ciclo-Oxigenase/farmacologia , Desenho de Fármacos , Edema/tratamento farmacológico , Pirrolidinas/farmacologia , Tiazolidinas/farmacologia , Animais , Anti-Inflamatórios não Esteroides/síntese química , Anti-Inflamatórios não Esteroides/química , Antineoplásicos/síntese química , Antineoplásicos/química , Proliferação de Células/efeitos dos fármacos , Células Cultivadas , Ciclo-Oxigenase 1/metabolismo , Ciclo-Oxigenase 2/metabolismo , Inibidores de Ciclo-Oxigenase/síntese química , Inibidores de Ciclo-Oxigenase/química , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Feminino , Células HT29 , Humanos , Células MCF-7 , Masculino , Estrutura Molecular , Pirrolidinas/síntese química , Pirrolidinas/química , Ratos , Bases de Schiff/síntese química , Bases de Schiff/química , Bases de Schiff/farmacologia , Relação Estrutura-Atividade , Tiazolidinas/química
12.
Spectrochim Acta A Mol Biomol Spectrosc ; 227: 117678, 2020 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-31676151

RESUMO

Two novel Schiff-base fluorescent probers SQ and NQ based on 8-hydroxyquinoline moiety were designed and synthesized. The both probes were capable of binding with Al3+ by naked eye detection to produce a significant fluorescence enhancement response with a detection limit of 1.48 × 10-8 and 4.23 × 10-8 M, respectively. At the same time, the formed complexes SQ-Al3+ and NQ-Al3+ could sequentially detect F-, and the detection limits of F- were determined to be 1.64 × 10-7 and 3.58 × 10-8 M, respectively. The "off-on-off" fluorescence response process demonstrated that the binding were reversible. The probes were further successfully utilized to detect Al3+ and F- in vitro PC12 cells.


Assuntos
Alumínio/análise , Corantes Fluorescentes/química , Flúor/análise , Imageamento Tridimensional , Bases de Schiff/química , Animais , Ânions , Corantes Fluorescentes/síntese química , Modelos Moleculares , Células PC12 , Espectroscopia de Prótons por Ressonância Magnética , Ratos , Bases de Schiff/síntese química , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta
13.
Int J Biol Macromol ; 146: 1100-1110, 2020 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-31682857

RESUMO

A novel, eco-friendly aminated chitosan Schiff's base (ACSSB@ZnO) was developed and utilized to remove MO from aqueous environment. The impact of different significant parameters, for example, pH (3-11), adsorbent dose (0.1-0.6 g), contact time (0-120 min), and temperature (303-323 K) have been explored by batch process. Kinetic data was illustrated by pseudo-second-order model and the isotherms fitted well with Langmuir isotherm model. The highest sorption capacity of ACSSB@ZnO was observed to be 111.11 mg/g at 323 K. Positive enthalpy and entropy values demonstrated that the MO adsorption procedure was an endothermic. Negative Gibbs free energy values implied the spontaneous nature of the adsorption system. Moreover, reusability experiments were studied and it can be regenerated by using NaOH as effluent.


Assuntos
Compostos Azo/isolamento & purificação , Quitosana/síntese química , Corantes/isolamento & purificação , Bases de Schiff/síntese química , Bases de Schiff/farmacologia , Poluentes Químicos da Água/isolamento & purificação , Adsorção , Aminação , Animais , Quitosana/química , Humanos , Concentração de Íons de Hidrogênio , Cinética , Células MCF-7 , Masculino , Camundongos , Espectroscopia de Prótons por Ressonância Magnética , Bases de Schiff/química , Espectroscopia de Infravermelho com Transformada de Fourier , Propriedades de Superfície , Fatores de Tempo , Difração de Raios X , Óxido de Zinco/química
14.
Spectrochim Acta A Mol Biomol Spectrosc ; 225: 117493, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31494382

RESUMO

A novel Schiff base fluorescent probe 7-Hydroxy-8-(((2-(hydroxymethyl)quinolin-8-yl)imino)methyl)-coumarin (XL) consist of formylcoumarin and aminoquinoline moieties was synthesized for dual detection of Zn2+ and Al3+ ions. Probe XL exhibited high selective and sensitive response towards Zn2+ and Al3+ ions through different color changes and significant fluorescence turn-on response (270 fold higher for Zn2+ and 230 fold higher for Al3+) in MeOH-H2O (4/1, v/v) over other cations, with detection limits (LOD) as low as 3.75 × 10-8 and 1.14 × 10-8 M, respectively. Moreover, probe XL exhibited preferential selectivity for Al3+ through displacing Zn2+ from the XL-Zn2+ complex by ligand-to-ligand transfer process. The binding mechanism of intramolecular charge transfer (ICT) were proposed from fluorescence and UV-vis titrations, Job's plot, 1H NMR titration, HRMS and DFT calculations. The probe was proven to be suitable for actual samples detection of Zn2+ and Al3+ ions. The complex XL-Zn2+ and XL-Al3+ exhibited dramatic fluorescent "turn-off" properties for PPi and PPi/F- respectively through snatching metal ions and released free XL. Moreover, probe XL showed low biotoxicity and sequentially "off-on-off" fluorescent bio-imaging of Zn2+/Al3+ and PPi/F- in PC12 cells.


Assuntos
Alumínio/análise , Corantes Fluorescentes/química , Zinco/análise , Animais , Sítios de Ligação , Corantes Fluorescentes/síntese química , Limite de Detecção , Microscopia de Fluorescência , Estrutura Molecular , Células PC12 , Papel , Ratos , Bases de Schiff/síntese química , Bases de Schiff/química , Espectrometria de Fluorescência
15.
J Fluoresc ; 29(6): 1467-1474, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31786706

RESUMO

The condensation product (L) of 4,4'-methylenedianiline and p-anisaldehyde acts as colorimetric sensor for Cu2+ and Pb2+ ions. On interaction with Cu2+, ethanolic solution of L changes its color to brown while it becomes light pink on interaction with Pb2+. Interaction of Al3+ with L coated paper strip emits bright blue fluorescence. Metal ions like Mg2+, Cu2+, Li+, K+, Na+, Mn2+, Al3+, Hg2+, Co2+, Pb2+, Ni2+, Cd2+, Zn2+, Fe3+ do not interfere the paper strip sensor. The fluorescent intensity of L in ethanol is quenched 25 times by Pb2+ ion. The interaction between L and Pb2+ is reversible and the detection limit of Pb2+ is 10-6 M. The binding constant and stoichiometry of binding between L and Pb2+ was calculated to be 104.8 and 1:2. Theoretical calculations show that the binding of the metal ions to L are favorable and the fluorescence of L is due to π → π* transition.


Assuntos
Alumínio/análise , Colorimetria , Cobre/análise , Corantes Fluorescentes/química , Chumbo/análise , Papel , Compostos de Anilina/química , Benzaldeídos/química , Teoria da Densidade Funcional , Corantes Fluorescentes/síntese química , Estrutura Molecular , Bases de Schiff/síntese química , Bases de Schiff/química
16.
Dalton Trans ; 48(47): 17673-17682, 2019 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-31763642

RESUMO

Four new Ce(iii) complexes 1-4 with tridentate NNO-donor Schiff base ligands have been designed and successfully synthesized. These complexes were characterized by elemental analysis, IR, and ESI-MS, with formulas of [Ce(HL1)2(NO3)3]·2CH3OH (1), [Ce(L2)2(NO3)]·3H2O (2), [Ce(HL3)(L3)(NO3)Br]·H2O (3) and [Ce(L4)2(NO3)]·3H2O (4), in which ligands HL1-HL4 are respectively N'-[(1E)-pyridin-2-ylmethylidene]pyrazine-2-carbohydrazide (HL1), 2-(1-(salicyloylhydrazono)ethyl)pyrazine (HL2), N'-[(1E)-pyridin-2-ylmethylidene]pyridine-2-carbohydrazide (HL3) and 2-(1-(salicyloylhydrazono)ethyl) pyridine (HL4). X-ray single crystal diffraction analysis indicates that complex 1 crystallizes in the monoclinic system with the space group C2/c and the structure of complex 1 consists of a monomeric Ce(iii) species with a Ce(iii) moiety bonded to two tridentate Schiff base ligands, three nitrates and solvents. These complexes effectively inhibit the enzyme activities of PTPs (SHP-1, SHP-2, TCPTP and PTP1B), among which complex 3 shows the most potent inhibition of SHP-2 with the lowest IC50 value of 0.61 µM and displays obvious selectivity towards SHP-2. Its inhibition potency against SHP-2 was approximately 17, 4, and 5 fold higher than that against SHP-1, TCPTP and PTP1B, respectively. Further study discloses that complex 3 inhibits SHP-2 in a competitive manner. Fluorescence measurements indicate that complex 3 tightly binds to SHP-2 with a molar ratio of 1 : 1 and a binding constant of 5.45 × 105 M-1. Western blot experiments show that complex 3 promotes the phosphorylation of the SHP-2 substrate by the combination of the inhibition of the activity and expression of SHP-2. Moreover, complex 3 decreases the survival rate of A549 cells to 35.12% at 100 µM and induces apoptosis with an apoptosis rate of 12.06% at 50 µM. All these results suggest that complex 3 is a potential bi-functional inhibitor of the activity and expression of tyrosine phosphatase SHP-2.


Assuntos
Antineoplásicos/farmacologia , Cério/farmacologia , Complexos de Coordenação/farmacologia , Inibidores Enzimáticos/farmacologia , Proteína Tirosina Fosfatase não Receptora Tipo 11/antagonistas & inibidores , Células A549 , Antineoplásicos/síntese química , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Cério/química , Complexos de Coordenação/síntese química , Complexos de Coordenação/química , Cristalografia por Raios X , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Humanos , Ligantes , Modelos Moleculares , Estrutura Molecular , Proteína Tirosina Fosfatase não Receptora Tipo 11/metabolismo , Bases de Schiff/síntese química , Bases de Schiff/química , Bases de Schiff/farmacologia , Relação Estrutura-Atividade
17.
Molecules ; 24(23)2019 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-31775342

RESUMO

Schiff base liquid crystals, known as [4-(hexyloxy)phenylimino)methyl]phenyl palmitate (IA), [4-(hexyloxy)phenylimino)methyl]phenyl oleate (IIA) and [4-(hexyloxy)phenylimino)methyl]phenyl linoleate (IIIA), were synthesized from palmitic, oleic, and linoleic natural fatty acids. The prepared compounds have been investigated for their thermal and optical behavior as well as phase formation using differential scanning calorimetry (DSC) and polarized optical microscopy (POM). Molecular structures of all studied compounds were confirmed via elemental analysis, FT-IR, 1H NMR, and 13C NMR. Smectic phase is the observed mesophase for all compounds; however, their type and range depend upon the terminal alkanoate chains attached to the phenyl ring. Computational calculations, Density functional theory (DFT), energy difference of the frontier molecular orbital (FMOs), as well as the thermodynamic parameters of different molecular configurations isomers were discussed. It was found that the mesophase behavior and the geometrical characteristics were affected by the degree of unsaturation of fatty terminal chains. Furthermore, the geometrical structure of the CH=N linkage plays an important role in the thermal stability and optical transition temperature.


Assuntos
Ésteres/química , Ácidos Graxos/química , Cristais Líquidos/química , Bases de Schiff/química , Varredura Diferencial de Calorimetria , Ésteres/síntese química , Ácidos Graxos/síntese química , Espectroscopia de Ressonância Magnética , Conformação Molecular , Estrutura Molecular , Óptica e Fotônica/métodos , Bases de Schiff/síntese química , Espectroscopia de Infravermelho com Transformada de Fourier , Termodinâmica , Temperatura de Transição
18.
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
19.
Metallomics ; 11(11): 1847-1863, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31553341

RESUMO

To develop new anti-tumour Pt(ii) agents, we designed and synthesized five Pt(ii) complexes. These Pt(ii) complexes were modified benzene rings of 2-hydroxybenzylidene with a hydrocarbyl or halogen group. The five Pt(ii) complexes possessed remarkable cytotoxicity against tumour cells in vitro. In particular, we investigated chemotherapeutic mechanisms of the complexes against A549cisR cells. The Pt(ii) complexes could bind to and cleave DNA, while also inducing arrest of the cell cycle in S phase, leading to down-regulation of the levels of cyclin-dependent kinases and cyclin and up-regulation of the expression of p21. The selected complex, C3, changed the mitochondrial membrane potential and induced apoptosis. C3 also inhibited the expression of the c-myc gene and downstream proteins, thereby inhibiting telomerase activity.


Assuntos
Hidrazonas/síntese química , Hidrazonas/farmacologia , Platina/farmacologia , Bases de Schiff/síntese química , Bases de Schiff/farmacologia , Animais , Apoptose/efeitos dos fármacos , Bovinos , Ciclo Celular/efeitos dos fármacos , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Forma Celular/efeitos dos fármacos , Cristalografia por Raios X , DNA/metabolismo , Humanos , Concentração Inibidora 50 , Ligantes , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Esferoides Celulares/efeitos dos fármacos , Esferoides Celulares/patologia , Telomerase/antagonistas & inibidores , Telomerase/metabolismo
20.
Molecules ; 24(17)2019 Aug 31.
Artigo em Inglês | MEDLINE | ID: mdl-31480486

RESUMO

Elucidation of the structure and function of biomolecules provides us knowledge that can be transferred into the generation of new materials and eventually applications in e.g., catalysis or bioassays. The main problems, however, concern the complexity of the natural systems and their limited availability, which necessitates utilization of simple biomimetic analogues that are, to a certain degree, similar in terms of structure and thus behaviour. We have, therefore, devised a small library of six tridentate N-heterocyclic coordinating agents (L1-L6), which, upon complexation, form two groups of artificial, monometallic non-heme iron species. Utilization of iron(III) chloride leads to the formation of the 1:1 (Fe:Ln) 'open' complexes, whereas iron(II) trifluoromethanosulfonate allows for the synthesis of 1:2 (M:Ln) 'closed' systems. The structural differences between the individual complexes are a result of the information encoded within the metallic centre and the chosen counterion, whereas the organic scaffold influences the observed properties. Indeed, the number and nature of the external hydrogen bond donors coming from the presence of (benz)imidazole moieties in the ligand framework are responsible for the observed biological behaviour in terms of mimicking phenoxazinone synthase activity and interaction with DNA.


Assuntos
Benzimidazóis/química , Materiais Biomiméticos/química , DNA/metabolismo , Ferro/química , Oxirredutases/metabolismo , Bases de Schiff/química , Aminofenóis/metabolismo , Animais , Ligação Competitiva , Catálise , Bovinos , Fluorescência , Imidazóis , Cinética , Ligantes , Oxazinas , Oxirredução , Bases de Schiff/síntese química , Elementos de Transição/metabolismo
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