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1.
Sci Rep ; 13(1): 20421, 2023 11 21.
Artigo em Inglês | MEDLINE | ID: mdl-37989862

RESUMO

The physicochemical properties of materials change significantly in nanometer dimensions. Therefore, several methods have been proposed for the synthesis of nanoparticles. Plant extracts and essential oils are applied as natural and economic resources to prepare nanomaterials especially metal nanoparticles. In this project, a green, simple and efficient method has been designed for the synthesis of Cu nanoparticles using Purple cabbage extract as a reducing and stabilizing agent. They were successfully loaded onto a new Ag complex containing 1,3,5-triazine Schiff base as ligand to form Cu@Ag-CPX nanocomposite. Phytochemical contents of extract were identified by standard qualitative analyses. The chemical structure of all synthesized compounds was characterized using spectral data. In FT-IR, coordination of C=N bond of Schiff base ligand to Ag+ ions shifted the absorption band from 1641 to 1632 cm-1. The UV-Vis spectrum of Cu@Ag-CPX nanocomposite shown the peak related to Cu nanoparticles in the region of around 251 nm. 5:7 molar ratio of Cu to Ag in Cu@Ag-CPX was determined using ICP-OES. The FESEM, TEM, and DLS techniques provided valuable insights into the morphology and size distribution of the nanocomposite, revealing the presence of rods and monodispersed particles with specific diameter ranges. These analyses of the nanocomposite displayed rods with diameters from 40 to 62 nm as well as monodispersed and uniform particles with average diameter of 45 nm, respectively. The presence of elements including carbon, nitrogen, oxygen, Cu and Ag was proved by EDX-EDS analysis. The XRD pattern of Cu@Ag-CPX shown the diffraction peaks of Cu and Ag particles at 2θ values of 10°-80°, and confirmed its crystalline nature. The inhibitory properties of the synthesized compounds were evaluated in vitro against four Gram-negative and two Gram-positive bacteria, as well as two fungal strains. The MIC, MBC and MFC values obtained from microdilution and streak plate sensitivity tests were ranged from 128 to 4096 µg ml-1. While Cu nanoparticles and Ag complexes were effective against some pathogens, they were not effective against all them. However, the growth of all tested microbial strains was inhibited by Cu@Ag-CPX nanocomposite, and makes it as a new promising antimicrobial agent. Modification of nanocomposite in terms of nanoparticle and complex can improve its blocking activities.


Assuntos
Anti-Infecciosos , Nanopartículas Metálicas , Espectroscopia de Infravermelho com Transformada de Fourier , Bases de Schiff/química , Ligantes , Anti-Infecciosos/farmacologia , Nanopartículas Metálicas/química , Extratos Vegetais/farmacologia , Antibacterianos/química , Testes de Sensibilidade Microbiana
2.
Helicobacter ; 28(5): e13004, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37391943

RESUMO

Nano-structure Cu(II) complex [Cu(AMAB)2 ]Cl2 with Schiff base (AMAB) derived from the condensation between 4-(dimethylamino)benzaldehyde and amoxicillin trihydrate was prepared. (AMAB) Schiff base and its Cu(II) complex were identified and confirmed by different physicochemical techniques. The Schiff base (AMAB) was coordinated to copper ion through carbonyl oxygen and imine nitrogen donor sites. X-ray powder diffraction shows a cubic crystal system of the Cu(II) complex. The density functional theory was used to optimize the structure geometries of the investigated compounds. The molecular docking of the active amino acids of the investigated proteins' interactions with the tested compounds was evaluated. The bactericidal or bacteriostatic effect of the compounds was screened against some bacterial strains. The activity of Cu-chelate against Gram-negative bacteria was mainly more effective than its (AMAB) ligand and vice versa in the case of Gram-positive bacteria. The biological activity of the prepared compounds with biomolecules calf thymus DNA (CT-DNA) was determined by electronic absorption spectra and DNA gel electrophoresis technique. All studies revealed that the Cu-chelate derivative exhibited better binding affinity to both CT-DNA than the AMAB and amoxicillin itself. The anti-inflammatory effect of the designed compounds was determined by testing their protein denaturation inhibitory activity spectrophotometrically. All obtained data supported that the designed nano-Cu(II) complex with Schiff base (AMAB) is a potent bactericide against H. pylori, and exhibits anti-inflammatory activity. The dual inhibition effects of the designed compound represent a modern therapeutic approach with extended spectrum of action. Therefore, it can act as good drug target in antimicrobial and anti-inflammtory therapies. Finally, H. pylori resistance to amoxicillin is absent or rare in many countries, thus amoxicillin nanoparticles may be beneficial for countries where amoxicillin resistance is reported.


Assuntos
Anti-Infecciosos , Infecções por Helicobacter , Helicobacter pylori , Humanos , Helicobacter pylori/metabolismo , Bases de Schiff/farmacologia , Bases de Schiff/química , Cobre/farmacologia , Cobre/química , Amoxicilina/farmacologia , Simulação de Acoplamento Molecular , Infecções por Helicobacter/tratamento farmacológico , Anti-Infecciosos/farmacologia , Antibacterianos/farmacologia , Antibacterianos/química , DNA/química , DNA/metabolismo , Testes de Sensibilidade Microbiana
3.
J Enzyme Inhib Med Chem ; 38(1): 2232125, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37403517

RESUMO

Nanotechnology-based strategies can overcome the limitations of conventional cancer therapies. Hence, novel series of pyrimidine Schiff bases (4-9) were employed in the synthesis of selenium nanoparticle forms (4NPs-9NPs). All selenium nano-sized forms exerted greater inhibitions than normal-sized compounds, far exceeding 5-fluorouracil activity. Compound 4 showed effective anti-proliferative activity against MCF-7(IC50 3.14 ± 0.04 µM), HepG-2(IC50 1.07 ± 0.03 µM), and A549(IC50 1.53 ± 0.01 µM) cell lines, while its selenium nanoform 4NPs showed excellent inhibitory effects, with efficacy increased by 96.52%, 96.45%, and 93.86%, respectively. Additionally, 4NPs outperformed 4 in selectivity against the Vero cell line by 4.5-fold. Furthermore, 4NPs exhibited strong inhibition of CDK1(IC50 0.47 ± 0.3 µM) and tubulin polymerase(IC50 0.61 ± 0.04 µM), outperforming 4 and being comparable to roscovitine (IC50 0.27 ± 0.03 µM) and combretastatin-A4(IC50 0.25 ± 0.01 µM), respectively. Moreover, both 4 and 4NPs arrested the cell cycle at G0/G1 phase and significantly forced the cells towards apoptosis. Molecular docking demonstrated that 4 and 4NPs were able to inhibit CDK1 and tubulin polymerase binding sites.


Assuntos
Antineoplásicos , Selênio , Relação Estrutura-Atividade , Antineoplásicos/química , Selênio/farmacologia , Tubulina (Proteína)/metabolismo , Simulação de Acoplamento Molecular , Proliferação de Células , Bases de Schiff/química , Linhagem Celular Tumoral , Pirimidinas/química , Ensaios de Seleção de Medicamentos Antitumorais , Estrutura Molecular
4.
Environ Sci Pollut Res Int ; 30(49): 106790-106811, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-36334198

RESUMO

Three new cross-linked chitosan derivatives were yielded through intensification of chitosan with diverse types of bis-aldehydes. The prepared cross-linked chitosan was characterized by FTIR, 1H NMR, XRD, and TGA techniques. TGA indicated an improvement in thermal stability of the cross-linked chitosan compared with pure chitosan. Batch adsorption experiments showed that the three novel cross-linked chitosan bis-aldehyde derivatives possessed good adsorption capacity against U(VI) in the order of BFPA > BFB > BODB (adsorption capacity of the three adsorbents for U(VI) reaches 142, 124, and 114 mg/g respectively) and the adsorption isotherm and kinetic were well described by the Langmuir and the pseudo-second-order kinetic model, respectively. In addition, the prepared cross-linked chitosan bis-aldehyde derivatives were examined as U(VI) catcher from waste solutions.


Assuntos
Quitosana , Urânio , Poluentes Químicos da Água , Quitosana/química , Urânio/química , Bases de Schiff/química , Água , Adsorção , Cinética , Poluentes Químicos da Água/química , Aldeídos , Concentração de Íons de Hidrogênio , Soluções
5.
Int J Biol Macromol ; 194: 611-618, 2022 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-34822818

RESUMO

In this work, a novel sustained released system (VCSB-Zn(II)) for zinc supplements was built by vanillin-chitosan Schiff base (VCSB) chelated with Zn2+ to improve the zinc trace element utilization ratio. Samples were characterized by FT-IR, 1H NMR, XRD, SEM, and TGA. The results showed that VCSB exhibited a more excellent chelation capacity of Zn2+ than chitosan. The chelation capacity of VCSB was about 1.7 times more than that of chitosan, corresponding to 50.96 mg/g and 29.91 mg/g, respectively. Furthermore, VCSB-Zn(II) showed excellent sustained released performance at simulated gastric fluid because of the acid slow-dissolving ability. And the higher the CN content of VCSB, the higher the cumulative release rate (Ri) of Zn2+, the highest Ri reached 77.81%. The sustained released curves were described by the first-order and Korsmeyer-Peppas equation, which described the Zn2+ sustained released performance caused by the dissolution of VCSB-Zn(II) and Fick diffusion. This Zn2+ sustained released system shows great potential in the application in the field of trace elements supplements for animals.


Assuntos
Benzaldeídos/química , Quitosana/química , Zinco/química , Liberação Controlada de Fármacos , Bases de Schiff/química
6.
Molecules ; 26(11)2021 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-34071327

RESUMO

Chitosan is the only cationic polysaccharide in nature. It is a type of renewable resource and is abundant. It has good biocompatibility, biodegradability and biological activity. The amino and hydroxyl groups in its molecules can be modified, which enables chitosan to contain a variety of functional groups, giving it a variety of properties. In recent years, researchers have used different strategies to synthesize a variety of chitosan derivatives with novel structure and unique activity. Structure combination is one of the main strategies. Therefore, we will evaluate the synthesis and agricultural antimicrobial applications of the active chitosan derivatives structure combinations, which have not been well-summarized. In addition, the advantages, challenges and developmental prospects of agricultural antimicrobial chitosan derivatives will be discussed.


Assuntos
Anti-Infecciosos/química , Materiais Biocompatíveis/química , Quitosana/química , Produtos Agrícolas , Polissacarídeos/química , Aldeídos/química , Antifúngicos/química , Proteção de Cultivos , Íons , Cetonas/química , Fósforo/química , Doenças das Plantas/prevenção & controle , Bases de Schiff/química , Enxofre/química
7.
ACS Appl Bio Mater ; 4(1): 428-440, 2021 01 18.
Artigo em Inglês | MEDLINE | ID: mdl-35014294

RESUMO

A layer-by-layer (L-B-L) bacterial cellulose (BC)-based transdermal patch has been prepared via a Schiff base reaction. The L-B-L assembly consisting of covalently cross-linked ethylene diamine-modified carboxymethylated BC isolated from the Glucanoacetobacter xylinus (MTCC7795) bacterial strain and aldehyde-modified pectin formed via a Schiff base reaction. The presence of the imine bond assists the self-healing process after being scratched in the presence of a pH 7.4 buffer solution monitored via optical microscopy, atomic force microscopy, and tensile strength analyses. The formation of the L-B-L assembly was confirmed using field-emission scanning electron microscopy (FESEM) analysis. Simultaneously, water swelling and deswelling studies were carried out to test its water retention efficiency. The presence of silver nanoparticles (AgNPs) has been confirmed by ultraviolet-visible spectroscopy and FESEM analyses. The antimicrobial activity of the AgNPs-incorporated transdermal patch has been examined over Staphylococcus aureus and Escherichia coli using the zone of inhibition method. Additionally, the cell viability assay was performed using the fluorescent dyes 4',6-diamidino-2-phenylindole and propidium iodide. The AgNPs in the L-B-L assembly showed antimicrobial property against both types of bacteria. The cytotoxicity and wound healing property of the patch system have been studied over NIH 3T3 fibroblast and A549 epithelial cell lines. The L-B-L film also influenced the wound healing process of these two cell lines.


Assuntos
Anti-Infecciosos/química , Celulose/química , Nanopartículas Metálicas/química , Bases de Schiff/química , Prata/química , Animais , Anti-Infecciosos/farmacologia , Bandagens , Movimento Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Gluconacetobacter xylinus/metabolismo , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Pectinas/química , Staphylococcus aureus/efeitos dos fármacos , Cicatrização/efeitos dos fármacos
8.
Molecules ; 25(24)2020 Dec 16.
Artigo em Inglês | MEDLINE | ID: mdl-33339433

RESUMO

Herein, we report the synthesis and characterization of a new Schiff base ligand 3-[[(E)-(3-hydroxyphenyl)-methylidene]amino]-2-methyl-quinazolin-4(3H)-one (HAMQ) and its Cd(II), Ni(II), Zn(II), and Cu(II) complexes (C1-C4). The ligand HAMQ was synthesized by reacting 3-hydroxybenzaldehyde and 3-amino-2-methyl-4(3H)-quinazolinone in a 1:1 molar ratio. The structure of the ligand and its complexes (C1-C4) were evaluated using ultraviolet (UV)-visible (Vis) light spectroscopy, 1H-NMR, Fourier-transform infrared (FT-IR) spectroscopy, MS, elemental analysis, conductance data, and thermogravimetric analysis (TGA). The characterization results suggested that the bidentate ligand, HAMQ, coordinated to the metal center through the lactum oxygen and the azomethine nitrogen. Moreover, all the metal complexes were analyzed using powder X-ray diffraction studies, which revealed that all of them belong to a triclinic crystal system. The research was supplemented by density functional theory (DFT) studies on the IR and UV-Vis spectra, as well as the chemical reactivity of the HAMQ and its four metallic derivatives making use of conceptual density functional theory (CDFT) by means of KID (Koopmans in DFT) methodology. The synthesized complexes displayed significant in vitro anticancer activity against human cancer cell lines (HeLa and HCT-115).


Assuntos
Antineoplásicos/química , Complexos de Coordenação/química , Quinazolinonas/química , Bases de Schiff/química , Antineoplásicos/farmacologia , Cádmio/química , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Complexos de Coordenação/farmacologia , Cobre/química , Teoria da Densidade Funcional , Humanos , Ligantes , Níquel/química , Espectrofotometria , Espectroscopia de Infravermelho com Transformada de Fourier , Zinco/química
9.
Food Chem ; 302: 125336, 2020 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-31419772

RESUMO

This study reports a stepwise optimization of switchable liquid-liquid microextraction (SLLME) for cobalt determination by flame atomic absorption spectrometry (FAAS) coupled with a slotted quartz tube (SQT). The main purpose of this study was to develop an accurate and sensitive analytical method for cobalt. Extraction method was used to separate and preconcentrate cobalt from sage tea and vitamin B12 samples after complexing with a Schiff base ligand. 107.7 folds enhancement in detection power under the optimum conditions was recorded with respect to direct FAAS. This enhancement correlated to 3.1 µg/L limit of detection and 10 µg/L limit of quantification. The SLLME-SQT-FAAS method was linear over a broad concentration range and low %RSD values established high precision for the method. Appreciable percent recovery results (94-108%) obtained from spiked sage sample and from cobalamin also validated the accuracy of the method.


Assuntos
Cobalto/análise , Microextração em Fase Líquida/métodos , Espectrofotometria Atômica/métodos , Chás de Ervas/análise , Vitamina B 12/análise , Limite de Detecção , Quartzo , Reprodutibilidade dos Testes , Salvia officinalis/química , Bases de Schiff/química , Espectrofotometria Atômica/instrumentação , Vitamina B 12/química
10.
Biopolymers ; 111(3): e23338, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31696516

RESUMO

A chitosan Schiff base with an aromatic aldehyde was synthesized and characterized by FTIR and NMR spectroscopies. Furthermore, the degree of substitution was calculated based on the ratios of the area of the proton of the imine (Aimine ) and the area of the peak of the proton of the pyranose ring (AH-2 ). The antimicrobial activities were determined against bacterial and fungal strains, as well as multiple drug-resistant (MDR) bacteria. The chitosan Schiff base was also tagged with medicinal plants, for example, Curcuma longa, Peganum harmala, Lepidium sativam, and cruciferous vegetables, and the biological activities determined against pathogenic bacterial and fungal strains. The chitosan Schiff base showed maximum zone of inhibition of 22 mm against Staphylococcus aureus with a minimum zone of inhibition of 15 mm against Bacillus cereus. The chitosan Schiff base was fused with C longa, isothiocyanates and a combined mixture of P harmala and L sativam that has shown activities against Escherichia coli with a zone of inhibition of 28, 24, and 30 mm, respectively. The Schiff base of chitosan fused with medicinal plants also showed significant inhibitory activities against MDR bacteria.


Assuntos
Anti-Infecciosos/química , Quitosana/química , Extratos Vegetais/química , Plantas Medicinais/química , Bases de Schiff/química , Anti-Infecciosos/farmacologia , Bacillus cereus/efeitos dos fármacos , Bactérias/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Fungos/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Modelos Químicos , Estrutura Molecular , Extratos Vegetais/farmacologia , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos
11.
Int J Biol Macromol ; 140: 588-599, 2019 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-31442510

RESUMO

A novel superoleophilic-hydrophobic nonanyl chitosan-poly (butyl acrylate) grafted copolymer was fabricated as a low-cost oil-adsorbent. Chitosan (CS) was coupled with a hydrophobic nonanal (N) to form nonanyl chitosan (NCS) schiff base, and followed by grafting with butyl acrylate monomers (ButA). The grafted copolymer was characterized by FTIR, TGA and SEM tools. The grafting percent was augmented and reached 88.5% with increasing ButA concentration up to 156 mM. Moreover, measurements of contact angle proved the superoleophilic character of NCS-g-poly (ButA) copolymer with an oil-contact angle 31°. Factors affecting the removal process such as contact time, oil type, oil dose, adsorbent dose, temperature and agitation speed were optimized. An increment in the oil removal (%) was observed with increasing the oil viscosity in the order of gasoil < mobil-1 oil < light crude oil < heavy crude oil. Besides, the adsorption process followed the pseudo-second order model and the equilibrium data were sufficiently fitted with the Langmuir model with a maximum adsorption capacity 108.79 g/g at 25 °C. Thermodynamic parameters computed from Van't Hoff plot confirmed the process to be exothermic, favorable and spontaneous. The results nominate the superoleophilic adsorbent as a potential oil- adsorbent for petroleum oil spills removal.


Assuntos
Acrilatos/química , Quitosana/química , Poluição por Petróleo/efeitos adversos , Petróleo/análise , Polímeros/química , Adsorção , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Bases de Schiff/química , Temperatura , Termodinâmica
12.
Pak J Pharm Sci ; 32(3): 963-967, 2019 May.
Artigo em Inglês | MEDLINE | ID: mdl-31278707

RESUMO

A new series of copper (II), cobalt (II), zinc (II), nickel (II), manganese (II), iron (II) complexes with a novel Schiff base were synthesized by the condensation of sulphadizine and thiophene-2-carbaldehyde.The ligand and its complexes were characterized by using diverse instrumental procedures like microanalysis, thermo gravimetric examination and spectroscopy. The integrated ligand and its metal complexes were subjected to antibacterial studies. These studies demonstrated the enhanced activity of metal complexes against reported microbes with respect to the Schiff base.


Assuntos
Anti-Infecciosos/síntese química , Anti-Infecciosos/farmacologia , Complexos de Coordenação/síntese química , Complexos de Coordenação/farmacologia , Metais/química , Anti-Infecciosos/química , Bacillus pumilus/efeitos dos fármacos , Clostridium butyricum/efeitos dos fármacos , Avaliação Pré-Clínica de Medicamentos , Enterobacter aerogenes/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Klebsiella oxytoca/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Bases de Schiff/química , Staphylococcus aureus/efeitos dos fármacos , Tiofenos/química
13.
Chem Commun (Camb) ; 55(44): 6269-6272, 2019 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-31086908

RESUMO

Porphyrin-based covalent organic polymer nanoparticles were synthesized via a Schiff base reaction at room temperature. The resulting product showed a good photodynamic effect and a high photothermal conversion efficiency (34.88%). Both in vitro and in vivo experiments demonstrated the enhanced antitumor efficacy via synergistic photodynamic and photothermal therapy.


Assuntos
Antineoplásicos/farmacologia , Nanopartículas , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacologia , Fototerapia/métodos , Polietilenoglicóis/farmacologia , Porfirinas/farmacologia , Animais , Antineoplásicos/química , Apoptose/efeitos dos fármacos , Células HeLa , Humanos , Camundongos , Microscopia Eletrônica de Varredura , Fármacos Fotossensibilizantes/química , Porfirinas/química , Difração de Pó , Bases de Schiff/química , Espectrofotometria Ultravioleta , Espectroscopia de Infravermelho com Transformada de Fourier , Termogravimetria , Ensaios Antitumorais Modelo de Xenoenxerto
14.
Int J Biol Macromol ; 127: 232-239, 2019 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-30641193

RESUMO

One of the most important problems in catalytic systems is metal leaching due to weak interactions between the supporting material and the metal ions. It adversely affects the reusability and catalytic performance of catalysts. In this study, a novel support material, which is a composed Schiff base functionalized pectin bio-polymer with good coordination performance against palladium ions, was designed and characterized to overcome the afore-mentioned problems. Then the catalytic activity of the designed pectin supported palladium catalyst (Pct-Pd) was evaluated in Suzuki-Miyaura coupling reactions. Pct-Pd catalyst provided excellent conversion yields in the reactions within 8 min. Additionally, Pct-Pd catalyst displayed superior reproducibility by giving 91% of conversion yield after 12 successive runs. Leaching test revealed that leaching of palladium ions from prepared support was negligible even after 12 runs. This study shows that the designed Pct-Pd catalyst can be transferred from academic laboratory to industrial applications due to its excellent reusability and catalytic activity.


Assuntos
Micro-Ondas , Paládio/química , Pectinas/química , Bases de Schiff/química
15.
J Inorg Biochem ; 191: 183-193, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30530179

RESUMO

Alzheimer's disease (AD) is one of the most common age-related neurodegenerative disorders. Aggregation of amyloid-ß peptide into extracellular plaques with incorporation of metal ions, such as Cu2+, and reduction of the neurotransmitter acetylcholine levels are among the factors associated to the AD brain. Hence, a series of 7-chloro-4-aminoquinoline Schiff bases (HLa-e) were synthesized and their cytotoxicity and anti-cholinesterase activity, assessed for Alzheimer's disease. The intrinsic relationship between Cu2+ and the amyloidogenic plaques encouraged us to investigate the chelating ability of HLa-e. Dimeric tetracationic compounds, [Cu2(NHLa-e)4]Cl4, containing quinoline protonated ligands were isolated from the reactions with CuCl2·2H2O and fully characterized in the solid state, including an X ray diffraction study, whereas EPR data showed that the complexes exist as monomers in DMSO solution. The inhibitory activity of all compounds was evaluated by Ellman's spectrophotometric method in acetylcholinesterase (AChE) from Electrophorus electricus and butyrylcholinesterase (BChE) from equine serum. HLa-e and [Cu(NHLd)2]Cl2 were selective for AChE (IC50 = 4.61-9.31 µM) and were not neurotoxic in primary brain cultures. Docking and molecular dynamics studies of HLa-e inside AChE were performed and the results suggested that these compounds are able to bind inside AChE similarly to other AChE inhibitors, such as donepezil. Studies of the affinity of HLd for Cu2+ in DMSO/HEPES at pH 6.6 and pH 7.4 in µM concentrations showed formation of analogous 1:2 Cu2+/ligand complexes, which may suggest that in the AD-affected brain HLd may scavenge Cu2+ and the complex, also inhibit AChE.


Assuntos
Aminoquinolinas/química , Inibidores da Colinesterase/farmacologia , Complexos de Coordenação/farmacologia , Cobre/química , Bases de Schiff/química , Animais , Células Cultivadas , Inibidores da Colinesterase/química , Complexos de Coordenação/química , Complexos de Coordenação/farmacocinética , Avaliação Pré-Clínica de Medicamentos , Técnicas In Vitro , Camundongos , Simulação de Acoplamento Molecular , Análise Espectral/métodos
16.
Acta Chim Slov ; 65(2): 416-428, 2018 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-29993095

RESUMO

Two novel copper(II) Schiff base complexes were synthesized and characterized by various physico-chemical and spectroscopic methods, revealing a distorted square planar geometry around the copper atom. The analytical data confirmed the 1:1 metal to ligand stoichiometry of the complexes. B3LYP/(LANL2DZ/6-311G**) density functional theory (DFT) were used to investigate structural and electronic properties of the synthesized compounds in gas phase. The computational results support the conclusion obtained by the experimental studies. Thermodynamic study of complex formation in solution was carried out spectrophotometrically at 25 °C. These compounds were also subjected to study in vitro antibacterial screening against some bacteria. Also, click reaction was investigated for its catalytic properties. The synthesized Schiff base copper complexes catalyzed 1,3-dipolar Huisgen cycloaddition of different functionalized ?-azido alcohols and alkynes in the presence of ascorbic acid in a solution of THF/H2O (2:1, V/V) at room temperature.


Assuntos
Antibacterianos/química , Complexos de Coordenação/química , Cobre/química , Bases de Schiff/química , Catálise , Avaliação Pré-Clínica de Medicamentos/métodos , Escherichia coli/efeitos dos fármacos , Ligantes , Modelos Moleculares , Estrutura Molecular , Staphylococcus aureus/efeitos dos fármacos , Relação Estrutura-Atividade , Termodinâmica
17.
Comb Chem High Throughput Screen ; 21(3): 194-203, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29436997

RESUMO

BACKGROUND: Malaria is one of the most vital infectious diseases caused by protozoan parasites of the Plasmodium genus. As P. falciparum, the cause of most of the severe cases of malaria, is increasingly resistant to available drugs such as amodioquine, chloroquine, artemisinin, and antifolates, there is an urgent need to identify new targets for chemotherapy. OBJECTIVE: This study screened novel pyrazole derivatives carrying iminium & benzothiazole group for antimalarial potential against P. falciparum chloroquine sensitive (3D7) strain. MATERIALS & METHODS: Several pyrazole schiff base hybrids with a wide range of substitution have been synthesized via condensation of substituted aniline with substituted 4-formylpyrazole and evaluated for their in vitro antimalarial activity against asexual blood stages of human malaria parasite, Plasmodium falciparum. The interaction of these conjugate hybrids was also investigated by molecular docking studies in the binding site of P. falciparum cystein protease falcipain-2. The pharmacokinetic properties were also studied using ADME prediction. RESULTS: Among all compounds, 6bf and 6bd were found to be potential molecules with EC50 1.95µg/ml and 1.98µg/ml respectively. Docking study results reveal that the pyrazole schiff base derivatives occupy the PfFP binding sites and they show good interactions with significant values of binding energies. CONCLUSION: We provide evidence which implicates pyrazole Schiff base hybrids as potential prototypes for the development of antimalarial agents.


Assuntos
Antimaláricos/síntese química , Pirazóis/uso terapêutico , Bases de Schiff/uso terapêutico , Antimaláricos/metabolismo , Benzotiazóis/química , Biologia Computacional , Cisteína Endopeptidases/metabolismo , Avaliação Pré-Clínica de Medicamentos , Humanos , Iminas/química , Simulação de Acoplamento Molecular , Plasmodium falciparum/efeitos dos fármacos , Plasmodium falciparum/enzimologia , Pirazóis/química , Bases de Schiff/química
18.
Anal Chem ; 90(6): 4119-4125, 2018 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-29466857

RESUMO

Selenocysteine (Sec) is a primary kind of reactive selenium species in cells, and its vital roles in physiological processes have been featured. Thus, the development of highly sensitive and selective methods for the sensing of Sec is of great significance. This work reports a turn-on fluorescent probe for selenol based on the unique fluorescence OFF-ON switching between the Schiff base (SB) and its complementary protonated Schiff base (PSB) form of merocyanine dyes. The probe consists of a merocyanine Schiff base fluorophore and a 2,4-dinitrobenzenesulfonamide moiety that reacts especially with selenol. The fluorescence turn-on response of MC-Sec is realized via the selective removal of the strongly electron withdrawing 2,4-dinitrobenzenesulfonyl group by Sec, leading to a shift in the p Ka of the imine nitrogen of the probe from 6.40 to 9.04 and thus significantly increasing the population of the fluorescent PSB form of the dye at physiological pH. MC-Sec shows good selectivity and sensitivity for Sec and has been applied in the imaging of exogenous and endogenous selenol in living cells by confocal fluorescence microscopy. The proposed mechanism should be useful for developing future probes directed to other target molecules by employing this simple but effective p Ka shift strategy.


Assuntos
Benzopiranos/química , Corantes Fluorescentes/química , Indóis/química , Imagem Óptica/métodos , Compostos de Selênio/análise , Linhagem Celular , Fluorescência , Humanos , Microscopia Confocal/métodos , Microscopia de Fluorescência/métodos , Bases de Schiff/química , Espectrometria de Fluorescência/métodos
19.
Int J Biol Macromol ; 110: 215-226, 2018 Apr 15.
Artigo em Inglês | MEDLINE | ID: mdl-29169947

RESUMO

O-Carboxymethyl chitosan (OCMC) Schiff's base was utilized for a new class of organic-inorganic hybrid material by grafting it on nano-silica-silane and further metallated with Cu (II). Here (3-Aminopropyl) triethoxysilane (APTES) was used as a linker and 2-hydroxy-1-naphthaldehyde (HN) for Schiff's base formation. The hybrid was characterized by FTIR, TGA, powder XRD, SEM, CHN, DLS, ICP-AES, diffuse reflectance UV-vis and EDX spectroscopic techniques. Magnetization measurements were carried out by VSM at room temperature. This study explored the possible synergic effect of unique properties of carboxymethyl chitosan, Schiff's base Cu (II) complex and nano-silica towards antibacterial activity and in dye degradation studies. The antibacterial performance of nano-hybrid material was examined against both Gram-positive (Escherichia coli) and Gram-negative (Bacillus subtilis) bacteria. The catalytic activity of the hybrid was tested for degradation of reactive black 5 (RB5) through advanced oxidation processes using H2O2 as oxidant. The results show a high dye degradation efficiency of 93% in 130min by the hybrid catalyst with reusability. As per published reports, Chitosan-Schiff's bases show strong antimicrobial activity and their Cu complexes exhibit good catalytic and anticancer activities. Therefore, it is expected that the new organic-inorganic hybrid would be highly applicable in environmental as well as biomedical fields.


Assuntos
Antibacterianos , Bacillus subtilis/crescimento & desenvolvimento , Bis-Fenol A-Glicidil Metacrilato , Cobre , Medicamentos de Ervas Chinesas , Escherichia coli/crescimento & desenvolvimento , Nanopartículas/química , Dióxido de Silício , Antibacterianos/química , Antibacterianos/farmacologia , Bis-Fenol A-Glicidil Metacrilato/química , Bis-Fenol A-Glicidil Metacrilato/farmacologia , Cobre/química , Cobre/farmacologia , Medicamentos de Ervas Chinesas/química , Medicamentos de Ervas Chinesas/farmacologia , Bases de Schiff/química , Bases de Schiff/farmacologia , Dióxido de Silício/química , Dióxido de Silício/farmacologia
20.
J Agric Food Chem ; 65(40): 8773-8778, 2017 Oct 11.
Artigo em Inglês | MEDLINE | ID: mdl-28942637

RESUMO

2-Hydroxy-4-methoxybenzaldehyde (HMBA) is a nontoxic phenolic flavor from dietary source Decalipus hamiltonii and Hemidesmus indicus. HMBA is an excellent antimicrobial agent with additional antiaflatoxigenic potency. On the other hand, cinnamaldehyde from cinnamon is a widely employed flavor with significant antiaflatoxigenic activity. We have attempted the enhancement of antiaflatoxigenic and antimicrobial properties of HMBA, cinnamaldehyde, and similar molecules via Schiff base formation accomplished from condensation reaction with amino sugar (d-glucamine). HMBA derived Schiff bases exhibited commendable antiaflatoxigenic activity at the concentration 0.1 mg/mL resulting in 9.6 ± 1.9% growth of Aspergillus flavus and subsequent 91.4 ± 3.9% reduction of aflatoxin B1 with respect to control.


Assuntos
Acroleína/análogos & derivados , Antifúngicos/farmacologia , Apocynaceae/química , Aspergillus flavus/efeitos dos fármacos , Benzaldeídos/farmacologia , Cinnamomum zeylanicum/química , Hemidesmus/química , Extratos Vegetais/farmacologia , Acroleína/química , Acroleína/farmacologia , Aflatoxina B1/metabolismo , Aldeídos/química , Aldeídos/farmacologia , Antifúngicos/química , Aspergillus flavus/crescimento & desenvolvimento , Aspergillus flavus/metabolismo , Benzaldeídos/química , Estrutura Molecular , Extratos Vegetais/química , Bases de Schiff/química , Bases de Schiff/farmacologia
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