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1.
Biosens Bioelectron ; 262: 116556, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38996596

RESUMO

The multiple-readout capability of multimodal detection enhances the flexibility, reliability, and accuracy of lateral flow immunoassay (LFIA). The conjugation of two different metal-organic frameworks (MOFs) as a new-generation composite material offers extraordinary opportunities for developing multimodal LFIA. It is anticipated to compensate limitations of traditional single colorimetric signal LFIA and improve the analysis performance. Herein, an ultra-bright fluorescent AIE-MOF was proposed and coupled with an in-situ growth of Prussian blue (PB) nanoparticles strategy to obtain a novel multimodal signal tracer (AIE-MOF@PB). Thereafter, it was successfully applied to develop the multimodal LFIA platform for the detection of nitrofurazone metabolites. The synergy of AIE-MOF and PB endows AIE-MOF@PB with superb water dispersibility, robust fluorescence emission, brilliant colorimetric signal, marvelous photothermal conversion, and enhanced antibody coupling efficiency, all of which facilitate a highly sensitive triple-readout LFIA platform. The detection sensitivity improved by at least 5-fold compared with the colloidal gold-based LFIA. This work not only inspires the rational design of aggregation-induced emission luminogens (AIEgen)-based complex materials but also highlights the promising potential in flexible point-of-care applications.


Assuntos
Técnicas Biossensoriais , Limite de Detecção , Estruturas Metalorgânicas , Nitrofurazona , Estruturas Metalorgânicas/química , Imunoensaio/métodos , Imunoensaio/instrumentação , Técnicas Biossensoriais/métodos , Nitrofurazona/análise , Nitrofurazona/química , Humanos , Ferrocianetos/química , Colorimetria/métodos , Corantes Fluorescentes/química
2.
Chemosphere ; 361: 142481, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38823428

RESUMO

The study presents the successful development of a new electrochemical sensor with low cost and disposability for application in nitrofurazone detection in environmental and pharmaceutical samples. The sensors were fabricated using materials obtained from local storage and conductive carbon ink. The modification of the screen-printed electrodes with the hybrid nanomaterial based on silver nanoparticles, carbon quantum dots, and carbon nanotubes showed synergistic contributions in the nitrofurazone electrooxidation, as observed in the wide linear range (0.008 at 15.051 µM), with a sensitivity of 0.650 µA/µM. The limit of detection obtained was 4.6 nM. Differential pulse voltammetry, cyclic voltammetry, X-ray photoelectron spectroscopy, X-ray diffraction analysis, and high-resolution transmission electron microscopy were used to evaluate the electrochemical and structural characteristics. Studies of possible interferences were considered with nitrofurazone in the presence of the ions and organic molecules. The results were satisfactory, with a variation of 93.3% ± 4.39% at 100% ± 2.40%. The low volume used in the analyses (50 µL), disposability, high sensibility, selectivity, and low limit of detection are advantages that make the proposed sensor an electrochemical tool of high viability for the NFZ detection in environmental matrices and pharmaceutical formulations.


Assuntos
Antibacterianos , Técnicas Eletroquímicas , Nanopartículas Metálicas , Nanotubos de Carbono , Nitrofurazona , Nitrofurazona/análise , Nitrofurazona/química , Técnicas Eletroquímicas/métodos , Nanotubos de Carbono/química , Nanopartículas Metálicas/química , Antibacterianos/análise , Limite de Detecção , Prata/química , Eletrodos , Pontos Quânticos/química
3.
Mikrochim Acta ; 191(6): 347, 2024 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-38802574

RESUMO

The synthesis of three-dimensional silver nanopopcorns (Ag NPCs) onto a flexible polycarbonate membrane (PCM) for the detection of nitrofurazone (NFZ) on the fish surface by surface-enhanced Raman spectroscopy (SERS) is presented. The proposed flexible Ag-NPCs/PCM SERS substrate exhibits significant Raman signal intensity enhancement with the measured enhancement factor of 2.36 × 106. This is primarily attributed to the hotspots created on Ag NPCs, including numerous nanoscale protrusions and internal crevices distributed across the surface of Ag NPCs. The detection of NFZ by this flexible SERS substrate demonstrates a low limit of detection (LOD) of 3.7 × 10-9 M and uniform and reproducible Raman signal intensities with a relative standard deviation below 8.34%. It also exhibits excellent stability, retaining 70% of its efficacy even after 10 days of storage. Notably, the practical detection of NFZ in tap water, honey water, and fish surfaces achieves LOD values of 1.35 × 10-8 M, 5.76 × 10-7 M, and 3.61 × 10-8 M, respectively,  which highlights its effectiveness across different sample types. The developed Ag-NPCs/PCM SERS substrate presents promising potential for sensitive SERS detection of toxic substances in real-world samples.


Assuntos
Limite de Detecção , Nanopartículas Metálicas , Nitrofurazona , Prata , Análise Espectral Raman , Análise Espectral Raman/métodos , Prata/química , Nitrofurazona/análise , Nitrofurazona/química , Nanopartículas Metálicas/química , Animais , Peixes , Mel/análise , Água Potável/análise , Cimento de Policarboxilato/química , Membranas Artificiais , Poluentes Químicos da Água/análise , Propriedades de Superfície , Contaminação de Alimentos/análise
4.
J Antibiot (Tokyo) ; 74(10): 758-762, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34326482

RESUMO

Four new quinofuracins F - I were isolated from the culture broth of Staphylotrichum boninense PF1444. The structures of quinofuracins F - I were elucidated by extensive spectroscopic analysis. These quinofuracins induced tumor suppressor protein p53-dependent cell death in human glioblastoma LNZTA3 cells.


Assuntos
Antineoplásicos/farmacologia , Ascomicetos/química , Nitrofurazona/análogos & derivados , Nitrofurazona/química , Antineoplásicos/química , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glioblastoma , Humanos , Estrutura Molecular , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
5.
Bioorg Chem ; 113: 104971, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-34051413

RESUMO

Drug repurposing has gained much attention as a cost-effective strategy that plays an exquisite role in identifying undescribed biological activities in clinical drugs. In the present work, we report the repurposing of the antibacterial drug nitrofurazone (NFZ) as a potential anticancer agent against CaCo-2, MDA-MB 231 and HepG-2 cancer cell lines. Novel series of nitrofurazone analogs were then designed considering the important pharmacologic features present in NFZ. Synthesis and biological evaluation of the target compounds revealed their promising anticancer activities endowed with antimicrobial potential and possessing better lipophilicity than NFZ. Compound 7, exclusively, inhibited the growth of all tested cancer cells more potently than NFZ with the least cytotoxicity against normal cells, displaying anti Gram-positive bacterial activities and antifungal potential. Analysis of the stereo-electronic properties of compound 7 via investigating the energies of HOMO, LUMO, HOMO-LUMO energy gap and MEP maps demonstrated its high reactivity and the expected molecular mechanism of action through reduction of the 5-nitrofuryl moiety. Data of the bioactivity studies indicated that the potent anticancer activity of 7 is mainly through increasing intracellular ROS levels and induction of apoptosis via significantly down-regulating the expression of Bcl-2 while up-regulating BAX, p53 and caspase 3 expression levels. Compound 7 potently inhibited the cellular expression levels of antioxidant enzymes GPx1 and GR compared to NFZ. Antioxidant enzymes kinetic studies and blind molecular docking simulations disclosed the mechanistic and structural aspects of the interaction between 7 and both GR and GPx1. Thus, the successful discovery of 7 as a potential dual anticancer-antimicrobial nitrofurazone analog might validate the applicability of drug repurposing strategy in unravelling the unrecognized bioactivity of the present conventional drugs, besides furnishing the way towards more optimization and development studies.


Assuntos
Antibacterianos/farmacologia , Antifúngicos/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Desenho de Fármacos , Nitrofurazona/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Antifúngicos/síntese química , Antifúngicos/química , Antineoplásicos/síntese química , Antineoplásicos/química , Candida albicans/efeitos dos fármacos , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Relação Dose-Resposta a Droga , Ensaios de Seleção de Medicamentos Antitumorais , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Humanos , Cinética , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Nitrofurazona/síntese química , Nitrofurazona/química , Relação Estrutura-Atividade
6.
Int J Mol Sci ; 22(4)2021 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-33671749

RESUMO

(1) Background: Environmental contamination with antibiotics is particularly serious because the usual methods used in wastewater treatment plants turn out to be insufficient or ineffective. An interesting idea is to support natural biodegradation processes with physicochemical methods as well as with bioaugmentation with efficient microbial degraders. Hence, the aim of our study is evaluation of the effectiveness of different methods of nitrofurazone (NFZ) degradation: photolysis and photodegradation in the presence of two photocatalysts, the commercial TiO2-P25 and a self-obtained Fe3O4@SiO2/TiO2 magnetic photocatalyst. (2) Methods: The chemical nature of the photocatalysis products was investigated using a spectrometric method, and then, they were subjected to biodegradation using the strain Achromobacter xylosoxidans NFZ2. Additionally, the effects of the photodegradation products on bacterial cell surface properties and membranes were studied. (3) Results: Photocatalysis with TiO2-P25 allowed reduction of NFZ by over 90%, demonstrating that this method is twice as effective as photolysis alone. Moreover, the bacterial strain used proved to be effective in the removal of NFZ, as well as its intermediates. (4) Conclusions: The results indicated that photocatalysis alone or coupled with biodegradation with the strain A. xylosoxidans NFZ2 leads to efficient degradation and almost complete mineralization of NFZ.


Assuntos
Achromobacter denitrificans/metabolismo , Nitrofurazona/isolamento & purificação , Poluentes Químicos da Água/isolamento & purificação , Achromobacter denitrificans/efeitos dos fármacos , Antibacterianos/isolamento & purificação , Biodegradação Ambiental , Catálise , Nitrofurazona/química , Nitrofurazona/toxicidade , Processos Fotoquímicos , Fotólise , Dióxido de Silício/química , Espectrofotometria Infravermelho , Titânio/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade
7.
J Hazard Mater ; 384: 121438, 2020 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-31629600

RESUMO

In this study, a self-biased bio-photoelectrochemical system (SB-BPES) was constructed using a bioanode and the g-C3N4/CdS heterojunction photocathode for nitrofurazone (NFZ) degradation under solar irradiation. The physio-chemical properties and optical performance of photocatalysts were characterized, and photo-electrochemical properties of various photocathodes were analyzed. Results showed that g-C3N4/CdS exhibited the broadest visible light absorption range (to 594 nm) and the most efficient e--h+ separation; and its corresponding photocathode showed the highest photocurrent (9.8 µA), and the lowest charge transfer resistance (5.43 ☓ 103 Ω). In the solar-illuminated SB-BPES with g-C3N4/CdS photocathode, about 80% of NFZ removal rate was achieved within 10 h. More importantly, TOC removal of 62.6% was achieved in 24 h, which was 1.8 times of that from the open circuit SB-BPES, and 4.3 folds of that from microbial degradation; also, about 1.5 times of those from SB-BPES with g-C3N4 and CdS photocathodes. Besides, reproducible current generations (∼1.0 mA) were produced. These verified that it was a self-sustained system for spontaneously pollutants degradation and electricity generation. Moreover, possible degradation mechanism and pathways were proposed according to the identified intermediates. This study provides inspiration for synchronic improving refractory organics degradation and net energy recovery.


Assuntos
Anti-Infecciosos/química , Anti-Infecciosos/metabolismo , Compostos de Cádmio/química , Nitrilas/química , Nitrofurazona/química , Nitrofurazona/metabolismo , Sulfetos/química , Bactérias/metabolismo , Biodegradação Ambiental , Compostos de Cádmio/efeitos da radiação , Catálise , Técnicas Eletroquímicas , Nitrilas/efeitos da radiação , Fotólise , Sulfetos/efeitos da radiação , Luz Solar
8.
Luminescence ; 35(4): 493-502, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-31883213

RESUMO

The interaction between DNA and furazolidone/furacillin was investigated using various analytical techniques including spectroscopy and electroanalysis and molecular modelling. With the aid of acridine orange (AO), the fluorescence lifetimes of DNA-AO, DNA-furazolidone/furacillin-AO remained almost the same, which proved that the ground state complex was formed due to furazolidone/furacillin binding with DNA. Circular dichroism spectra and Fourier transform infrared spectroscopy showed that the second structure of DNA changed. Viscosity experiments presented that relative viscosity of DNA was increased with the increasing concentrations of furazolidone and almost unchanged for furacilin. In addition, the results of melting temperature (Tm ), ionic strength, site competition experiments, cyclic voltammetry, and molecular docking all proved the intercalation binding mode for furazolidone and groove binding mode for furacilin. The binding constants (Ka ) obtained from Wolfe-Shimmer equation were calculated as 3.66 × 104 L mol-1 and 3.95 × 104 L mol-1 for furazolidone-DNA and furacilin-DNA, respectively.


Assuntos
DNA/química , Técnicas Eletroquímicas , Furazolidona/química , Simulação de Acoplamento Molecular , Nitrofurazona/química , Sítios de Ligação , Dicroísmo Circular , Espectroscopia de Infravermelho com Transformada de Fourier , Viscosidade
9.
Artigo em Inglês | MEDLINE | ID: mdl-31481448

RESUMO

The global spread of multidrug-resistant enterobacteria warrants new strategies to combat these pathogens. One possible approach is the reconsideration of "old" antimicrobials, which remain effective after decades of use. Synthetic 5-nitrofurans such as furazolidone, nitrofurantoin, and nitrofurazone are such a class of antimicrobial drugs. Recent epidemiological data showed a very low prevalence of resistance to this antimicrobial class among clinical Escherichia coli isolates in various parts of the world, forecasting the increasing importance of its uses to battle antibiotic-resistant enterobacteria. However, although they have had a long history of clinical use, a detailed understanding of the 5-nitrofurans' mechanisms of action remains limited. Nitrofurans are known as prodrugs that are activated in E. coli by reduction catalyzed by two redundant nitroreductases, NfsA and NfsB. Furazolidone, nevertheless, retains relatively significant antibacterial activity in the nitroreductase-deficient ΔnfsA ΔnfsBE. coli strain, indicating the presence of additional activating enzymes and/or antibacterial activity of the unreduced form. Using genome sequencing, genetic, biochemical, and bioinformatic approaches, we discovered a novel 5-nitrofuran-activating enzyme, AhpF, in E. coli The discovery of a new nitrofuran-reducing enzyme opens new avenues for overcoming 5-nitrofuran resistance, such as designing nitrofuran analogues with higher affinity for AhpF or screening for adjuvants that enhance AhpF expression.


Assuntos
Escherichia coli/enzimologia , Nitrorredutases/metabolismo , Antibacterianos/metabolismo , Antibacterianos/farmacologia , Farmacorresistência Bacteriana/genética , Escherichia coli/efeitos dos fármacos , Escherichia coli/genética , Proteínas de Escherichia coli/genética , Proteínas de Escherichia coli/metabolismo , Furazolidona/química , Furazolidona/farmacologia , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Nitrofuranos/metabolismo , Nitrofuranos/farmacologia , Nitrofurantoína/química , Nitrofurantoína/farmacologia , Nitrofurazona/química , Nitrofurazona/farmacologia , Nitrorredutases/genética , Peroxirredoxinas/genética , Peroxirredoxinas/metabolismo
10.
J Mol Graph Model ; 92: 303-312, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31434035

RESUMO

A computational strategy in consideration of attachment energy, temperature, solubility and supersaturation unravels details of the solvent effect on the crystal morphology. The crystal morphologies were predicted by the advanced screw dislocation growth model. This research sheds much light on the crystal growth mechanisms with the example of 3,4-bis(3-nitrofurazan-4-yl)furoxan (DNTF) in ethanol. The solvation model based on the experiment situation was established into periodic supercell. Molecular dynamics simulation was performed for obtaining the adsorption energy at the equilibrium state of the interface layer. The growth characteristics of relevant growth faces are introduced. At the same time, a periodic bond chains analysis can be applied to the existence and evolution of crystal growth units. The prediction results are in remarkable agreement with the experimental results. We found that crystal morphology of DNTF is composed of (002), (111), (111¯) and (101) faces in ethanol. As the saturation temperature rises, the (101) face becomes smaller and eventually disappears.


Assuntos
Cristalização , Etanol/química , Modelos Teóricos , Simulação de Dinâmica Molecular , Nitrofurazona/análogos & derivados , Oxidiazóis/química , Algoritmos , Nitrofurazona/química
11.
J Biomed Mater Res B Appl Biomater ; 107(5): 1551-1559, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30267643

RESUMO

The failures of glutaraldehyde (GLUT) cross-linked bioprosthetic heart valves (BHVs) are mainly due to degeneration and calcification. In this study, we developed a new preparation strategy for BHVs named as "HPA/EDC/EGCG" that utilized 3,4-hydroxyphenylpropionic acid (HPA)-conjugated pericardium, epigallocatechin gallate (EGCG), and horseradish peroxidase (HRP)/hydrogen peroxide (H2 O2 ) enzymatic cross-linking. HPA-pericardium conjugation was done by carbodiimide coupling reaction using 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide (EDC) and N-hydroxysuccinimide (NHS). Then HPA-conjugated pericardium was cross-linked by HRP/H2 O2 enzyme-catalyzed oxidation. The feeding ratios of HPA and EGCG were optimized. The consumption of amino groups, collagenase and elastase degradation in vitro, biomechanics, extracellular matrix stability, and calcification of HPA-/EDC-/EGCG-treated pericardiums were characterized. We demonstrated that HPA-/EDC-/EGCG-treated pericardiums had better elastin stabilization and less calcification. EGCG and enzymatic cross-linking treated pericardiums showed improved mechanical properties. This new EGCG and enzymatic cross-linking strategy would be a promising method to make BHVs with better elastin stability and anti-calcification property. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 1551-1559, 2019.


Assuntos
Calcificação Fisiológica/efeitos dos fármacos , Catequina/análogos & derivados , Elastina/química , Elastina/metabolismo , Próteses Valvulares Cardíacas , Valvas Cardíacas/transplante , Benzocaína/química , Benzocaína/metabolismo , Fenômenos Biomecânicos , Bioprótese , Coagulação Sanguínea/efeitos dos fármacos , Catequina/química , Catequina/metabolismo , Cloranfenicol/química , Cloranfenicol/metabolismo , Reagentes de Ligações Cruzadas/química , Desmosina/química , Desmosina/metabolismo , Combinação de Medicamentos , Etildimetilaminopropil Carbodi-Imida/química , Matriz Extracelular/química , Matriz Extracelular/metabolismo , Glutaral/metabolismo , Peroxidase do Rábano Silvestre/química , Humanos , Peróxido de Hidrogênio/química , Nitrofurazona/química , Nitrofurazona/metabolismo , Pericárdio/química
12.
Int J Exp Pathol ; 99(5): 236-248, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30320480

RESUMO

Hydroxymethylnitrofurazone (NFOH) is a nitrofurazone prodrug effective in vivo during acute infections, and it has less hepatotoxicity effect than the standard drug benznidazole (BZN) which has been used during short- and long-term treatment. In the present study, we induced the indeterminate form of Chagas disease in mice with a Y strain of Trypanosoma cruzi and analysed the histopathological data about the effects of NFOH and BZN on different tissues, including the heart, skeletal muscle, liver, kidney, colon, spleen and brain. After infection, BALB/c mice were treated with NFOH (150 mg/kg) and BZN (60 mg/kg) for 60 days and then submitted to immunosuppression using dexamethasone (5 mg/kg) for 14 days. Two trained analysts, as part of a blind evaluation, examined the results using serial sections of 3 mm diameter in two different moments. The results showed reactivation of the disease only in the infected nontreated group (POS). After treatment, amastigote nests were found in the heart, colon, liver and skeletal muscle in the POS group and in the heart and liver of the BZN group. Interestingly, amastigote nests were not found in the NFOH and NEG groups. The histopathological analysis showed fewer tissue lesions and parasite infiltrates in the NFOH group when compared with the BZN and POS groups. We have not observed any increase in the levels of hepatocellular injury biomarkers (AST/ALT) in the NFOH group. These in vivo studies show the potential for NFOH as an effective and safe compound useful as an anti-T. cruzi agent.


Assuntos
Doença de Chagas/tratamento farmacológico , Nitrofurazona/análogos & derivados , Trypanosoma cruzi/efeitos dos fármacos , Animais , Doença de Chagas/parasitologia , Doença de Chagas/patologia , Modelos Animais de Doenças , Inflamação/tratamento farmacológico , Inflamação/parasitologia , Inflamação/patologia , Rim/efeitos dos fármacos , Rim/patologia , Fígado/parasitologia , Fígado/patologia , Masculino , Camundongos , Músculo Esquelético/patologia , Nitrofurazona/química , Nitrofurazona/farmacologia , Nitroimidazóis/uso terapêutico
13.
Eur J Med Chem ; 121: 553-560, 2016 Oct 04.
Artigo em Inglês | MEDLINE | ID: mdl-27318979

RESUMO

Chagas disease, caused by Trypanosoma cruzi, is a parasitosis that predominates in Latin America. It is estimated that 25 million people are under the risk of infection and, in 2008, more than 10 thousand deaths were registered. The only two drugs available in the therapeutics, nifurtimox and benznidazole, showed to be more effective in the acute phase of the disease. However, there is no standard treatment protocol effective for the chronic phase. Nitrofurazone (NF), an antimicrobial drug, has activity against T. cruzi, although being toxic. Considering the need for new antichagasic drugs, the existence of promising new therapeutic targets, as 14α-sterol demethylase and cruzain, and employing the bioisosterism and molecular hybridization approaches, four novel compounds were synthesized, characterized by melting point range, elemental analysis, IR and NMR spectroscopy. The compounds were tested against T. cruzi amastigotes in infected U2OS cells. All compounds showed selectivity towards T. cruzi and showed trypanomicidal activity in low micromolar range. The compound 3 showed potency similar to benznidazole, but lower efficacy. These results highlight the importance of the 1,2,4-triazole, thiosemicarbazonic and nitro group moieties for designing new efficient compounds, potentially for the chronic phase of Chagas disease.


Assuntos
Nitrofurazona/síntese química , Nitrofurazona/farmacologia , Triazóis/química , Tripanossomicidas/síntese química , Tripanossomicidas/farmacologia , Trypanosoma cruzi/efeitos dos fármacos , Linhagem Celular Tumoral , Técnicas de Química Sintética , Humanos , Hidrazonas/química , Modelos Moleculares , Conformação Molecular , Nitrofurazona/química , Tripanossomicidas/química
14.
Artigo em Inglês | MEDLINE | ID: mdl-27048728

RESUMO

Two new polymorphic forms of 5-nitrofurazone (5-nitro-2-furaldehyde semicarbazone) have been synthesized and structurally characterized by single-crystal and powder X-ray diffraction methods, vibrational spectroscopy (FT-IR and temperature Raman), differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and Hirshfeld surface analysis. The compound crystallizes in three different polymorphic forms P21/a (polymorph α), P21 (polymorph ß) and P21/c (polymorph γ), the crystal structures of two of which (polymorphs ß and γ) represent new structure determinations. The solid-state molecular organization in the three crystal forms is analyzed and discussed in terms of molecular conformation, crystal packing and hydrogen-bonded networks. All three crystals are formed from trans geometrical isomers, but the molecular conformation of the α-polymorph is syn-anti-anti-anti, while that of ß- and γ-polymorphs is syn-anti-syn-syn. As a consequence of this the hydrogen-bond donor and acceptor sites of the molecules are oriented differently, which in turn results in different hydrogen-bond connectivity and packing patterns.


Assuntos
Anti-Infecciosos/química , Nitrofurazona/química , Anti-Infecciosos/síntese química , Cristalografia por Raios X , Modelos Moleculares , Conformação Molecular , Nitrofurazona/síntese química
15.
Mater Sci Eng C Mater Biol Appl ; 59: 310-318, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26652378

RESUMO

A newly developed modified coacervation method is utilized to synthesize gelatin nano/submicron particles (GN/SPs) as a drug carrier. Binary nonsolvent aided coacervation (BNAC) method is a modified single step coacervation method, which has yielded approximately a threefold lower particle size and higher average yield in terms of weight percentage of around 94% in comparison to the conventional phase separation methods. In this study 0.5% (w/v) gelatin aqueous solution with a binary nonsolvent system of acetone and ethanol was used. Nanoparticle synthesis was optimized with respect to nonsolvent system type and pH. pH7 has resulted a minimum particle size of 55.67 (±43.74) nm in anhydrous medium along with a swollen particle size of 776nm (±38.57) in aqueous medium with a zeta potential of (-16.3±3.51) mV in aqueous medium. Swelling ratio of 13.95 confirms the crosslinked hydrogel nature of the particles. Furthermore, drug loading efficiency of the gelatin particles prepared at 7pH was observed with nitrofurazone as the model drug. Results of drug release study indicate the potential use of GN/SPs as drug loading matrix for wound management such as burn wound management.


Assuntos
Portadores de Fármacos , Gelatina , Hidrogéis , Nanopartículas/química , Nitrofurazona , Queimaduras/tratamento farmacológico , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Portadores de Fármacos/farmacologia , Gelatina/química , Gelatina/farmacocinética , Gelatina/farmacologia , Hidrogéis/química , Hidrogéis/farmacocinética , Hidrogéis/farmacologia , Nitrofurazona/química , Nitrofurazona/farmacocinética , Nitrofurazona/farmacologia
16.
Anal Bioanal Chem ; 407(30): 8971-7, 2015 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-26427505

RESUMO

Reliably detecting nitrofurazone (NFZ) residues in farmed crab and shrimp was previously hindered by lack of appropriately specific analytical methodology. Parent NFZ rapidly breaks down in meat, and the commonly used side-chain metabolite, semicarbazide (SEM), is non-specific as it occurs naturally in crustacean shell often leading to 'false positive' detections in meat. Using 5-nitro-2-furaldehyde (NF) as marker metabolite, following pre-column derivatization with 2,4-dinitrophenylhydrazine (DNPH), ultra-performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) analysis in negative electrospray ionization mode enabled confirmation of NFZ residues in deliberately treated whole crab, crab meat and shrimp meat, with a limit of detection (LOD) and limit of quantification (LOQ) below 1 ng g(-1). Meanwhile, the derivatives of DNPH-NF were synthesized for the first time, purified by preparative liquid chromatography and structure characterized with nuclear magnetic resonance spectroscopy ((1)H-NMR). The purity of derivative was checked by ultra-performance liquid chromatography-tunable ultraviolet (UPLC-TUV), and the contents were beyond 99.9%. For comparison purposes, crustacean samples were analysed using both NF and SEM marker metabolites. NFZ treatment was revealed by both NF and SEM marker metabolites, but untreated crab also showed measurable levels of SEM which could potentially be misinterpreted as evidence of illegal NFZ use.


Assuntos
Biomarcadores/química , Cromatografia Líquida de Alta Pressão/métodos , Resíduos de Drogas/química , Nitrofurazona/química , Palaemonidae/química , Frutos do Mar/análise , Espectrometria de Massas em Tandem/métodos , Animais , Biomarcadores/metabolismo , Braquiúros/química , Resíduos de Drogas/metabolismo , Contaminação de Alimentos/análise , Furaldeído/análogos & derivados , Furaldeído/química , Furaldeído/metabolismo , Estrutura Molecular , Nitrofurazona/metabolismo , Semicarbazidas/química , Semicarbazidas/metabolismo
17.
Anal Biochem ; 491: 1-3, 2015 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-26361820

RESUMO

Traditional methods for regulating oxygen concentration ([O2]) in in vitro experiments over the range found in normal and tumor tissues require the use of expensive equipment to generate controlled gas atmospheres or the purchase of a range of gas cylinders with certified O2 percentages. Here we describe a simple and inexpensive enzymatic method for generating low, precise steady-state [O2] levels that are stable for several hours. This method is particularly applicable to the in vitro study of some classes of hypoxia-targeted antitumor prodrugs and bioreductively activated agents.


Assuntos
Oxigênio/análise , Catalase/metabolismo , Glucose/metabolismo , Glucose Oxidase/metabolismo , NADPH-Ferri-Hemoproteína Redutase/metabolismo , Nitrofurazona/química , Nitrofurazona/metabolismo , Oxirredução , Oxigênio/química , Pró-Fármacos/química , Pró-Fármacos/metabolismo
18.
Water Res ; 72: 281-92, 2015 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-25660806

RESUMO

Antibiotics in wastewaters must be degraded to eliminate their antibacterial activity before discharging into the environment. A cathode can provide continuous electrons for the degradation of refractory pollutants, however the cathodic degradation feasibility, efficiency and pathway for different kinds of antibiotics is poorly understood. Here, we investigated the degradation of four antibiotics, namely nitrofurazone (NFZ), metronidazole (MNZ), chloramphenicol (CAP), and florfenicol (FLO) by a poised cathode in a dual chamber electrochemical reactor. The cyclic voltammetry preliminarily proved the feasibility of the cathodic degradation of these antibiotics. The cathodic reducibility of these antibiotics followed the order of NFZ > MNZ > CAP > FLO. A decreased phosphate buffered solution (PBS) concentration as low as 2 mM or utilization of NaCl buffer solution as catholyte had significant influence on antibiotics degradation rate and efficiency for CAP and FLO but not for NFZ and MNZ. PBS could be replaced by Na2CO3-NaHCO3 buffer solution as catholyte for the degradation of these antibiotics. Reductive dechlorination of CAP proceeded only after the reduction of the nitro group to aromatic amine. The composition of the degradation products depended on the cathode potential except for MNZ. The cathodic degradation process could eliminate the antibacterial activity of these antibiotics. The current study suggests that the electrochemical reduction could serve as a potential pretreatment or advanced treatment unit for the treatment of antibiotics containing wastewaters.


Assuntos
Antibacterianos/química , Técnicas Eletroquímicas/métodos , Antibacterianos/farmacologia , Soluções Tampão , Cloranfenicol/química , Cloranfenicol/farmacologia , Eletrodos , Escherichia coli/efeitos dos fármacos , Escherichia coli/crescimento & desenvolvimento , Lactococcus lactis/efeitos dos fármacos , Lactococcus lactis/crescimento & desenvolvimento , Espectrometria de Massas , Metronidazol/química , Metronidazol/farmacologia , Testes de Sensibilidade Microbiana , Nitrofurazona/química , Soluções , Tianfenicol/análogos & derivados , Tianfenicol/química , Tianfenicol/farmacologia , Testes de Toxicidade
19.
Curr Pharm Biotechnol ; 15(2): 182-90, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-25135342

RESUMO

The goal of the research work entertained herein was the development and characterization of a poly-(vinyl alcohol) (PVA) hydrogel cross-linked with glutaraldehyde and impregnated with 0.2% (w/w) nitrofurazone (NTZ), for topical applications. To verify the active principle release capability, one has determined (i) swelling profile, (ii) in vitro release of NTZ via UV-VIS spectrophotometry, and (iii) antimicrobial activity via exposure to the hydrogel of ATCC strains of Staphylococcus aureus, Escherichia coli and Pseudomonas aeruginosa. The optimized hydrogel was further characterized via scanning electron microscopy (SEM), infrared spectroscopy with Fourier transform, moisture content determinations and thermal analyses via thermal gravimetry (TGA). Swelling tests revealed a mass increase from 100±5% up to 350±11%. Incorporated NTZ displayed bactericidal activity, as expected, being released in a linearly controlled fashion above 6 µg/mL during experiment timeframes of 14 h. SEM analyses allowed verification of a homogeneous surface morphology, while infrared spectra showed that NTZ did not bind strongly to the cross-linked polymer. Furthermore, results from thermal analyses suggested a loss of thermal stability arising from incorporation of NTZ in the hydrogel. The optimized hydrogel exhibited characteristics with high potential for (antimicrobial) treatment of skin lesions.


Assuntos
Anti-Infecciosos/química , Hidrogéis/química , Nitrofurazona/química , Administração Tópica , Liberação Controlada de Fármacos , Microscopia Eletrônica de Varredura , Espectrofotometria Infravermelho , Termogravimetria
20.
Curr Pharm Biotechnol ; 14(12): 1036-47, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24433503

RESUMO

Nitrofurazone (NTZ) is usually employed in the topical treatment of infected wounds and lesions of both skin and mucosa. Microencapsulation is a process utilized in the incorporation of active ingredients within polymers aiming at, among other objectives, the prolonged release of pharmaceutical compounds and protection from atmospheric agents (viz. moisture, light, heat and/or oxidation). With the goal of utilizing the microparticles containing encapsulated NTZ in pharmaceutical formulations, one prepared microparticles containing NTZ via ionotropic gelation of sodium alginate. The microparticles were characterized via scanning electron microscopy analyses, Fourier transform infrared spectroscopy (FTIR) analyses, via determination of encapsulation efficiency, and via thermal analyses (both TGA and DSC). The final gel formulation was also characterized rheologically. The extrusion/solidification technique employed to obtain the calcium alginate microparticles with encapsulated NTZ was found to be adequate, and produced an NTZ encapsulation efficiency of ca. 97.8% ± 1.1%. The calcium alginate microparticles thus obtained, with encapsulated NTZ, exhibited an oval shape and hydrodynamic diameters between 500 µm and 800 µm. From the thermal analyses performed, together with information from the infrared spectra, one may conclude that NTZ did not strongly bind to the polymer, which may be favorable for the release of the active ingredient. From the results obtained in the present research effort, one may conclude that the microparticles produced possess the potential to be utilized as carriers for NTZ in pharmaceutical formulations such as gels, ointments, and solutions.


Assuntos
Alginatos/química , Anti-Infecciosos/química , Portadores de Fármacos/química , Nitrofurazona/química , Administração Tópica , Anti-Infecciosos/administração & dosagem , Anti-Infecciosos/farmacologia , Química Farmacêutica , Composição de Medicamentos/métodos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Escherichia coli/efeitos dos fármacos , Géis , Ácido Glucurônico/química , Ácidos Hexurônicos/química , Nitrofurazona/administração & dosagem , Nitrofurazona/farmacologia , Tamanho da Partícula , Pseudomonas aeruginosa/efeitos dos fármacos , Reologia , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície
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