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1.
Yakugaku Zasshi ; 140(9): 1101-1106, 2020.
Artigo em Japonês | MEDLINE | ID: mdl-32879242

RESUMO

Organoselenium compounds have attracted significant interest because of their use as important reagents in organic syntheses and potential biological activities, necessitating the development of simple and general synthetic methods. This article reviews our studies to develop of copper-catalyzed C-Se bond formation reactions via cross coupling and C-H activation. A number of unsymmetrical and symmetrical diaryl selenides were synthesized via Se-arylation of diaryl diselenides or selenium powder with triarylbismuthanes under aerobic conditions, achieving moderate to excellent yields. When the reaction of triphenylbismuthane with elemental Se was monitored with gas chromatography, diphenyl diselenide and diphenyl selenide formation was confirmed. Subsequently, 1-pot 2-step reactions were performed under mild conditions to obtain 3-selanyl imidazo[1,2-a]pyridines from triarylbismuthanes and diimidazopyridyl diselenides, which were generated from imidazo[1,2-a]pyridines and Se powder, in good to excellent yields. It should be noted that all three aryl groups in the bismuth and both selanyl groups in the diaryl diselenide generated from the selenium source were transferred to the coupling products. Cu-catalyzed tandem cyclization of 2-(2-iodophenyl)imidazo[1,2-a]pyridines with selenium for the synthesis of benzo[b]selenophene-fused imidazo[1,2-a]pyridines is also described herein. The molecular structure of the tetracyclic compound features nearly coplanar rings, and the maximum absorption is red-shifted compared to those of imidazo[1,2-a]pyridine and benzoselenophene.


Assuntos
Carbono/química , Cobre/química , Hidrogênio/química , Compostos Organosselênicos/síntese química , Catálise , Ciclização , Ligação de Hidrogênio , Fenômenos de Química Orgânica
2.
Anticancer Res ; 40(10): 5399-5404, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32988859

RESUMO

BACKGROUND/AIM: The aim of the present study was to investigate whether idarubicin (IDR) induces oxidative DNA damage in the presence of copper (II). MATERIALS AND METHODS: DNA damage was evaluated by pBR322 plasmid DNA cleavage. The formation of oxidative stress markers [O2 •- and 8-hydroxy-2'-deoxyguanosine (8-OHdG)] was analysed. RESULTS: IDR induced DNA damage and O2 •- and 8-OHdG generation in the presence of copper (II). CONCLUSION: IDR induced oxidative DNA damage in the presence of copper (II). Since it has been reported that the concentration of copper in the serum of cancer patients is higher than that in healthy groups, IDR-induced oxidative DNA damage in the presence of copper (II) may play an important role in anticancer therapeutic strategies.


Assuntos
Antraciclinas/farmacologia , Idarubicina/farmacologia , Neoplasias/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Antraciclinas/química , Cobre/química , Dano ao DNA/efeitos dos fármacos , Humanos , Idarubicina/química , Neoplasias/genética , Neoplasias/patologia , Espécies Reativas de Oxigênio/química , Superóxido Dismutase/genética
3.
Nat Commun ; 11(1): 4557, 2020 09 11.
Artigo em Inglês | MEDLINE | ID: mdl-32917908

RESUMO

Why metalloenzymes often show dramatic changes in their catalytic activity when subjected to chemically similar but non-native metal substitutions is a long-standing puzzle. Here, we report on the catalytic roles of metal ions in a model metalloenzyme system, human carbonic anhydrase II (CA II). Through a comparative study on the intermediate states of the zinc-bound native CA II and non-native metal-substituted CA IIs, we demonstrate that the characteristic metal ion coordination geometries (tetrahedral for Zn2+, tetrahedral to octahedral conversion for Co2+, octahedral for Ni2+, and trigonal bipyramidal for Cu2+) directly modulate the catalytic efficacy. In addition, we reveal that the metal ions have a long-range (~10 Å) electrostatic effect on restructuring water network in the active site. Our study provides evidence that the metal ions in metalloenzymes have a crucial impact on the catalytic mechanism beyond their primary chemical properties.


Assuntos
Anidrases Carbônicas/química , Íons/química , Metaloproteínas/química , Metais/química , Sítios de Ligação , Anidrase Carbônica II/química , Anidrase Carbônica II/metabolismo , Anidrases Carbônicas/metabolismo , Catálise , Domínio Catalítico , Cobalto/química , Cobre/química , Cristalografia por Raios X , Humanos , Íons/metabolismo , Cinética , Metaloproteínas/metabolismo , Metais/metabolismo , Modelos Moleculares , Níquel/química , Conformação Proteica , Relação Estrutura-Atividade , Especificidade por Substrato , Zinco/química
4.
Orv Hetil ; 161(35): 1488-1496, 2020 08.
Artigo em Húngaro | MEDLINE | ID: mdl-32822328

RESUMO

Copper is an essential micronutrient for the human body, taking part in several metabolic processes. It is required for the terminal oxidation, the elimination of free radicals, the proper functioning of iron metabolism, the synthesis of hormones, neurotransmitters and the stabilization of the extracellular matrix. Copper is a two-faced element. Its significance in protein-bounded form is undeniable, but free copper causes severe cell damage mainly through free radical reactions, substituting other essential metals in protein structure, and it has various effects on cell signaling pathways. The amount of copper present in the human body is part of a delicate balance. Both its deficiency and excess can develop severe symptoms and diseases. The nutritional copper balance is rarely broken, because the average daily consumption excessively covers the needs, and the body's copper stores can tolerate the temporary differences. Genetic diseases (Menkes and Wilson disease) helped to understand the copper metabolism and understand the clinical symptoms of deficiency and excessive intake. The role of copper in the development of chronic diseases is receiving increasing attention. Recent studies show its significance in neurodegenerative and cancerous diseases, both in pathogenesis and as a therapeutic target. Orv Hetil. 2020; 161(35): 1488-1496.


Assuntos
Cobre/química , Cobre/metabolismo , Radicais Livres , Degeneração Hepatolenticular/genética , Humanos , Metais , Neoplasias/genética , Oligoelementos
5.
J Chromatogr A ; 1627: 461395, 2020 Sep 13.
Artigo em Inglês | MEDLINE | ID: mdl-32823100

RESUMO

Nowadays, enantioseparation of racemic pharmaceuticals in preparations is a prime concern by drug authorities across the globe. In the present work, it was attempted to develop novel enantioselective extraction method for five clinically used drugs (atenolol, propranolol, metoprolol, racecadotril, and raceanisodamine in their tablets) as racemates. The enantioselective solid-liquid extraction of these racemic drugs was carried out successfully by the use of chiral ionic liquid (CIL) in combination with a metal organic framework (MOF) for the first time. The composite CIL@MOF was synthesized from tropine based chiral ionic liquids with L-proline anion ([CnTr][L-Pro], n=3-6) and HKUST-1 type MOF, which was comprehensively characterized before being used as sorbent for enantioselective dispersive solid-liquid extraction. Preliminary selection of appropriate CIL was carried out on thin layer chromatography (TLC); under the joint participation of copper ion in the developing reagent, [C3Tr][L-Pro] ionic liquid showed better resolution performance with ΔRf value of 0.35 between the enantiomers was obtained for racemic atenolol. Moreover, the effect of copper salt dosage, amount of CIL, soli-liquid ratio and extraction time were investigated. The optimal conditions were obtained after thorough investigations; i.e. sample solution: ethanol, elution solvent: methanol, solid-liquid ratio: 12.5 mg:50 mL, amount of copper salt: 8 mg L-1, amount of impregnated CIL: 30% and extraction time of 30 min. As a result, enantiomeric excess values are 90.4%, 95%, 92%, 81.6% and 83.2% for atenolol, propranolol, metoprolol, racecadotril and raceanisodamine, respectively. The developed enantioselective method was validated following ICH guidelines and it was proved to be simple, effective and enantioselective way for separation of racemic pharmaceuticals with similar behaviors.


Assuntos
Líquidos Iônicos/química , Estruturas Metalorgânicas/química , Preparações Farmacêuticas/isolamento & purificação , Extração em Fase Sólida/métodos , Antagonistas Adrenérgicos beta/análise , Antagonistas Adrenérgicos beta/isolamento & purificação , Atenolol/análise , Atenolol/isolamento & purificação , Cromatografia Líquida de Alta Pressão/métodos , Cobre/química , Metoprolol/análise , Metoprolol/isolamento & purificação , Preparações Farmacêuticas/análise , Propranolol/análise , Propranolol/isolamento & purificação , Solventes/química , Estereoisomerismo
6.
PLoS One ; 15(8): e0237599, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785287

RESUMO

The microbial oxidation of metal sulfides plays a major role in the formation of acid rock drainage (ARD). We aimed to broadly characterize the ARD at Ely Brook, which drains the Ely Copper Mine Superfund site in Vermont, USA, using metagenomics and metatranscriptomics to assess the metabolic potential and seasonal ecological roles of microorganisms in water and sediment. Using Centrifuge against the NCBI "nt" database, ~25% of reads in sediment and water samples were classified as acid-tolerant Proteobacteria (61 ± 4%) belonging to the genera Pseudomonas (2.6-3.3%), Bradyrhizobium (1.7-4.1%), and Streptomyces (2.9-5.0%). Numerous genes (12%) were differentially expressed between seasons and played significant roles in iron, sulfur, carbon, and nitrogen cycling. The most abundant RNA transcript encoded the multidrug resistance protein Stp, and most expressed KEGG-annotated transcripts were involved in amino acid metabolism. Biosynthetic gene clusters involved in secondary metabolism (BGCs, 449) as well as metal- (133) and antibiotic-resistance (8501) genes were identified across the entire dataset. Several antibiotic and metal resistance genes were colocalized and coexpressed with putative BGCs, providing insight into the protective roles of the molecules BGCs produce. Our study shows that ecological stimuli, such as metal concentrations and seasonal variations, can drive ARD taxa to produce novel bioactive metabolites.


Assuntos
Ácidos/química , Metagenoma , Microbiota , Mineração , Proteobactérias/genética , Proteobactérias/metabolismo , Transcriptoma , Cobre/química , Marcadores Genéticos , Minerais/química , Proteobactérias/crescimento & desenvolvimento
7.
Chemosphere ; 255: 127013, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32679631

RESUMO

In order to obtain higher agricultural yields, the use of chemical substances has been increased to prevent the proliferation of pests, as well as ensuring durability in the storage of the food produced. Such substances are known as pesticides that may well present risks to human health and the environment. In the presence of metal ions, these substances can interact forming new species with different characteristics. Carbendazim (MBC) is an example of a harmful pesticide, which has atoms of nitrogen and oxygen in its structure that can form complexes with metal ions. Thus, in this work has studied the interaction between the copper (II) metal ion and carbendazim and its formation in natural water. The Cu-MBC complex showed a reduction peak of 0.007 V and an oxidation peak of 0.500 V, with characteristics of a quasi-reversible process under a glassy carbon electrode. By anodic stripping voltammetry, a different behavior was observed in the interaction of copper and carbendazim in ultrapure water and Billings dam water; however, it was possible to observe the complex in both samples. Carbendazim in the presence of the metal shows lower oxidation potential value, indicating the influence of the metal on the electrochemical response of the pesticide.


Assuntos
Benzimidazóis/química , Carbamatos/química , Cobre/química , Poluentes Químicos da Água/química , Carbono/química , Técnicas Eletroquímicas/métodos , Eletrodos , Oxirredução
8.
ACS Appl Mater Interfaces ; 12(31): 34723-34727, 2020 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-32657566

RESUMO

SARS-CoV-2, the virus that causes the disease COVID-19, remains viable on solids for periods of up to 1 week, so one potential route for human infection is via exposure to an infectious dose from a solid. We have fabricated and tested a coating that is designed to reduce the longevity of SARS-CoV-2 on solids. The coating consists of cuprous oxide (Cu2O) particles bound with polyurethane. After 1 h on coated glass or stainless steel, the viral titer was reduced by about 99.9% on average compared to the uncoated sample. An advantage of a polyurethane-based coating is that polyurethane is already used to coat a large number of everyday objects. Our coating adheres well to glass and stainless steel as well as everyday items that people may fear to touch during a pandemic, such as a doorknob, a pen, and a credit card keypad button. The coating performs well in the cross-hatch durability test and remains intact and active after 13 days of being immersed in water or after exposure to multiple cycles of exposure to the virus and disinfection.


Assuntos
Betacoronavirus/genética , Infecções por Coronavirus/genética , Pandemias , Pneumonia Viral/genética , Betacoronavirus/patogenicidade , Cobre/química , Cobre/metabolismo , Infecções por Coronavirus/virologia , Humanos , Pneumonia Viral/virologia , Poliuretanos/química , Poliuretanos/metabolismo , Propriedades de Superfície
9.
J Cancer Res Ther ; 16(3): 440-444, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32719248

RESUMO

Introduction: Crystallization test is based on the principle that, when a salt crystallizes out of an aqueous solution, the crystal growth is influenced by the presence of other substances in the solution, such as blood or plant extracts. If a mixture of copper chloride solution with a small amount of whole blood is allowed to crystallize under controlled experimental conditions, an aggregate of crystals forms. Crystallization method can be used as a diagnostic aid to provide information about the systemic conditions and general health of the patient. Aim: This study aims to study the patterns of crystallization and to further determine the efficacy of crystallization test as a screening modality in premalignant lesions and oral squamous cell carcinoma (OSCC). Materials and Methods: Fifty patients of OSCC, 50 patients of premalignant lesions, and 50 healthy individuals were selected. One drop of blood was collected from the study groups to perform crystallization using cupric chloride. Statistical Analysis Used: Statistical analysis was performed using Chi-square test, Student's t-test (two-tailed), and analysis of variance. Results: The different patterns of crystals formed were studied and statistically analyzed. Conclusion: Based on the study, it was concluded that Crystallization test can be used as an effective screening modality for detection of premalignant lesions and OSCC.


Assuntos
Biomarcadores Tumorais/análise , Carcinoma de Células Escamosas/diagnóstico , Cobre/química , Cristalização/métodos , Leucoplasia/sangue , Neoplasias Bucais/diagnóstico , Lesões Pré-Cancerosas/diagnóstico , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/sangue , Carcinoma de Células Escamosas/química , Estudos de Casos e Controles , Feminino , Humanos , Leucoplasia/patologia , Masculino , Programas de Rastreamento , Pessoa de Meia-Idade , Neoplasias Bucais/sangue , Neoplasias Bucais/química , Estadiamento de Neoplasias , Lesões Pré-Cancerosas/sangue , Adulto Jovem
10.
Food Chem ; 332: 127376, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32615382

RESUMO

In this work, a molecularly imprinted sensor employing copper sulfide (CuS) as a novel signal probe was successfully developed for ultrasensitive and selective determination of sulfathiazole (STZ). The reduction signals of Cu2+ produced in the process of electron transfer of CuS containing large amounts of Cu2+ are easy to be captured, which provide high electrochemical signals. Moreover, gold nanoparticles@covalent organic framework with excellent conductivity was introduced on the electrode surface for signal amplification and facilitating electron transfer processes of CuS. Under optimized testing conditions, the proposed sensor offered a linear DPV response to STZ over a very wide concentration range (1.0 × 10-4 to 1.0 × 10-11 mol L-1), with a limit of detection of 4.3 × 10-12 mol L-1. Fodder and mutton samples spiked with STZ were analyzed using this sensor, and the satisfactory recoveries ranging from 83.0% to 107.2% were obtained. In addition, the proposed sensor was used to determine the concentration of STZ in chicken liver and pork liver, with quantification results being near identical to those determined by high-performance liquid chromatography.


Assuntos
Cobre/química , Eletroquímica/instrumentação , Ouro/química , Limite de Detecção , Nanopartículas Metálicas/química , Impressão Molecular , Sulfatiazóis/análise , Eletrodos , Sulfatiazóis/química
11.
Chemosphere ; 260: 127574, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32688316

RESUMO

Artisanal and small-scale gold mining (ASGM) operations are major contributors to the Philippines' annual gold (Au) output (at least 60%). Unfortunately, these ASGM activities lacked adequate tailings management strategies, so contamination of the environment is prevalent. In this study, soil contamination with copper (Cu), lead (Pb), zinc (Zn) and arsenic (As) due to ASGM activities in Nabunturan, Davao de Oro, Philippines was investigated. The results showed that ASGM-impacted soils had Cu, Pb, Zn and As up to 3.6, 83, 73 and 68 times higher than background levels, respectively and were classified as 'extremely' polluted (CD = 30-228; PLI = 5.5-34.8). Minerals typically found in porphyry copper-gold ores like pyrite, chalcopyrite, malachite, galena, sphalerite and goethite were identified by XRD and SEM-EDS analyses. Furthermore, sequential extraction results indicate substantial Cu (up to 90%), Pb (up to 50%), Zn (up to 65%) and As (up to 48%) partitioned with strongly adsorbed, weak acid soluble, reducible and oxidisable fractions, which are considered as 'geochemically mobile' phases in the environment. Although very high Pb and Zn were found in ASGM-impacted soils, they were relatively immobile under oxidising conditions around pH 8.5 because of their retention via adsorption to hydrous ferric oxides (HFOs), montmorillonite and kaolinite. In contrast, Cu and As release from the historic ASGM site samples exceeded the environmental limits for Class A and Class C effluents, which could be attributed to the removal of calcite and dolomite by weathering. The enhanced desorption of As at around pH 8.5 also likely contributed to its release from these soils.


Assuntos
Mineração , Poluentes do Solo/análise , Poluentes do Solo/química , Solo/química , Arsênico/análise , Arsênico/química , Cobre/análise , Cobre/química , Ouro/análise , Ferro/química , Compostos de Ferro/química , Chumbo/análise , Chumbo/química , Minerais/química , Filipinas , Sulfetos/química , Difração de Raios X , Zinco/análise , Zinco/química
12.
PLoS One ; 15(7): e0235642, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32640001

RESUMO

Aspergillus tamarii grows abundantly in naturally composting waste fibers of the textile industry and has a great potential in biomass decomposition. Amongst the key (hemi)cellulose-active enzymes in the secretomes of biomass-degrading fungi are the lytic polysaccharide monooxygenases (LPMOs). By catalyzing oxidative cleavage of glycoside bonds, LPMOs promote the activity of other lignocellulose-degrading enzymes. Here, we analyzed the catalytic potential of two of the seven AA9-type LPMOs that were detected in recently published transcriptome data for A. tamarii, namely AtAA9A and AtAA9B. Analysis of products generated from cellulose revealed that AtAA9A is a C4-oxidizing enzyme, whereas AtAA9B yielded a mixture of C1- and C4-oxidized products. AtAA9A was also active on cellopentaose and cellohexaose. Both enzymes also cleaved the ß-(1→4)-glucan backbone of tamarind xyloglucan, but with different cleavage patterns. AtAA9A cleaved the xyloglucan backbone only next to unsubstituted glucosyl units, whereas AtAA9B yielded product profiles indicating that it can cleave the xyloglucan backbone irrespective of substitutions. Building on these new results and on the expanding catalog of xyloglucan- and oligosaccharide-active AA9 LPMOs, we discuss possible structural properties that could underlie the observed functional differences. The results corroborate evidence that filamentous fungi have evolved AA9 LPMOs with distinct substrate specificities and regioselectivities, which likely have complementary functions during biomass degradation.


Assuntos
Aspergillus/metabolismo , Proteínas Fúngicas/metabolismo , Glucanos/metabolismo , Oxigenases de Função Mista/metabolismo , Xilanos/metabolismo , Sequência de Aminoácidos , Sítios de Ligação , Cromatografia Líquida de Alta Pressão , Clonagem Molecular , Cobre/química , Cobre/metabolismo , Proteínas Fúngicas/classificação , Proteínas Fúngicas/genética , Glucanos/análise , Glucanos/química , Oxigenases de Função Mista/classificação , Oxigenases de Função Mista/genética , Oxirredução , Filogenia , Polissacarídeos , Proteínas Recombinantes/biossíntese , Proteínas Recombinantes/isolamento & purificação , Especificidade por Substrato , Xilanos/química
13.
Food Chem ; 332: 127398, 2020 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-32610260

RESUMO

Herein, a label-free and dual-readout immunochromatographic test strip (ITS) for the sensitive detection of Escherichia coli (E. coli) O157:H7 by taking advantages of the strong capture ability of Fe3O4@CuS nanostructures (NSs) towards bacteria and their ultrahigh photothermal effects (PTEs) was reported. Especially, without the customarily antibody (Ab)-labeled probe, Fe3O4@CuS NSs could be adsorbed onto the surfaces of bacteria to form Fe3O4@CuS-bacteria conjugates and then trapped by immobilized Abs on the test line (T-line), forming a characteristic yellow band. After direct immunoreactions, the PTEs of Fe3O4@CuS NSs endowed T-line to be irradiated by an 808 nm infrared light, obtaining satisfactory sensitivity and accuracy. Under optimal conditions, E. coli O157:H7, as low as 103 and 102 CFU/mL, could be monitored in colorimetric and photothermal modes. Additionally, E. coli O157:H7 was successfully detected in beef, chicken, milk and honey samples by this proposed platform with a recovery of 80-120%.


Assuntos
Cromatografia de Afinidade/métodos , Cobre/química , Escherichia coli O157/isolamento & purificação , Compostos Férricos/química , Microbiologia de Alimentos/métodos , Animais , Anticorpos Monoclonais/imunologia , Bovinos , Galinhas/microbiologia , Cromatografia de Afinidade/instrumentação , Escherichia coli O157/imunologia , Microbiologia de Alimentos/instrumentação , Mel/microbiologia , Limite de Detecção , Leite/microbiologia , Fitas Reagentes/química , Carne Vermelha/microbiologia
14.
Proc Natl Acad Sci U S A ; 117(32): 19178-19189, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32723819

RESUMO

Lytic polysaccharide monooxygenases (LPMOs) have a unique ability to activate molecular oxygen for subsequent oxidative cleavage of glycosidic bonds. To provide insight into the mode of action of these industrially important enzymes, we have performed an integrated NMR/electron paramagnetic resonance (EPR) study into the detailed aspects of an AA10 LPMO-substrate interaction. Using NMR spectroscopy, we have elucidated the solution-phase structure of apo-BlLPMO10A from Bacillus licheniformis, along with solution-phase structural characterization of the Cu(I)-LPMO, showing that the presence of the metal has minimal effects on the overall protein structure. We have, moreover, used paramagnetic relaxation enhancement (PRE) to characterize Cu(II)-LPMO by NMR spectroscopy. In addition, a multifrequency continuous-wave (CW)-EPR and 15N-HYSCORE spectroscopy study on the uniformly isotope-labeled 63Cu(II)-bound 15N-BlLPMO10A along with its natural abundance isotopologue determined copper spin-Hamiltonian parameters for LPMOs to markedly improved accuracy. The data demonstrate that large changes in the Cu(II) spin-Hamiltonian parameters are induced upon binding of the substrate. These changes arise from a rearrangement of the copper coordination sphere from a five-coordinate distorted square pyramid to one which is four-coordinate near-square planar. There is also a small reduction in metal-ligand covalency and an attendant increase in the d(x2-y2) character/energy of the singly occupied molecular orbital (SOMO), which we propose from density functional theory (DFT) calculations predisposes the copper active site for the formation of a stable Cu-O2 intermediate. This switch in orbital character upon addition of chitin provides a basis for understanding the coupling of substrate binding with O2 activation in chitin-active AA10 LPMOs.


Assuntos
Bacillus licheniformis/enzimologia , Proteínas de Bactérias/química , Quitina/metabolismo , Oxigenases de Função Mista/química , Oxigênio/metabolismo , Bacillus licheniformis/química , Proteínas de Bactérias/metabolismo , Domínio Catalítico , Quitina/química , Cobre/química , Cobre/metabolismo , Espectroscopia de Ressonância de Spin Eletrônica , Imagem por Ressonância Magnética , Oxigenases de Função Mista/metabolismo , Oxigênio/química , Especificidade por Substrato
15.
Chemosphere ; 260: 127528, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32682132

RESUMO

Acid mine drainage (AMD) which involves high sulfur and heavy metals concentrations and furthermore are acidic in character, has been a major environmental and economic issue due to the associated toxicity and treatment costs. A large quantity of AMD in nature has a variety of resources including water and heavy metals such as Cu, Al, Fe and Ni. In this study, the valuable resource of Cu was selectively recovered from model AMD solution through membrane distillation and adsorption systems. Direct contact membrane distillation (DCMD) system enabled to concentrate the Cu concentration in AMD by more than 2.5 times while recovering 80% of high-quality water for reuse purposes. For adsorption, mesoporous silica material was used after multi-modification with Mn and amine grafting to enhance the adsorption capacity as well as selectivity for Cu. Under acidic conditions, heavy metals cannot be adsorbed on amine grafted SBA-15. Therefore, the pH of synthetic AMD (pH = 2.2) had to be adjusted to the 5.0-5.2 range, in order to enable adsorption of Cu on modified SBA-15 (this is to prevent protonation of amine groups grafted on prepared SBA-15). Moreover, an increase in pH helped to precipitate more than 99% of Fe and Al (predominant metals in AMD). Cu adsorption on modified SBA-15 was 24.53 mg/g for KOH-treated AMD. However, Cu adsorption on modified SBA-15 decreased by 26% (18.11 mg/g) for NaOH-treated AMD. Cu adsorption with modified SBA-15 significantly improved to 55.75 mg/g when the Cu concentration was concentrated by DCMD.


Assuntos
Cobre/química , Mineração , Eliminação de Resíduos Líquidos/métodos , Poluentes Químicos da Água/química , Ácidos , Adsorção , Destilação , Concentração de Íons de Hidrogênio , Metais Pesados/análise , Poluentes Químicos da Água/análise
16.
Nat Commun ; 11(1): 2788, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32493916

RESUMO

Oxidative stress is associated with many acute and chronic inflammatory diseases, yet limited treatment is currently available clinically. The development of enzyme-mimicking nanomaterials (nanozymes) with good reactive oxygen species (ROS) scavenging ability and biocompatibility is a promising way for the treatment of ROS-related inflammation. Herein we report a simple and efficient one-step development of ultrasmall Cu5.4O nanoparticles (Cu5.4O USNPs) with multiple enzyme-mimicking and broad-spectrum ROS scavenging ability for the treatment of ROS-related diseases. Cu5.4O USNPs simultaneously possessing catalase-, superoxide dismutase-, and glutathione peroxidase-mimicking enzyme properties exhibit cytoprotective effects against ROS-mediated damage at extremely low dosage and significantly improve treatment outcomes in acute kidney injury, acute liver injury and wound healing. Meanwhile, the ultrasmall size of Cu5.4O USNPs enables rapid renal clearance of the nanomaterial, guaranteeing the biocompatibility. The protective effect and good biocompatibility of Cu5.4O USNPs will facilitate clinical treatment of ROS-related diseases and enable the development of next-generation nanozymes.


Assuntos
Cobre/química , Depuradores de Radicais Livres/química , Inflamação/patologia , Nanopartículas/química , Tamanho da Partícula , Espécies Reativas de Oxigênio/química , Lesão Renal Aguda/sangue , Lesão Renal Aguda/patologia , Lesão Renal Aguda/terapia , Alanina Transaminase/sangue , Animais , Antioxidantes/química , Aspartato Aminotransferases/sangue , Bovinos , Cobre/farmacocinética , Feminino , Células HEK293 , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Nanopartículas/ultraestrutura , Análise de Componente Principal , Ratos Sprague-Dawley , Distribuição Tecidual , Cicatrização
17.
Nat Commun ; 11(1): 2778, 2020 06 08.
Artigo em Inglês | MEDLINE | ID: mdl-32513979

RESUMO

The use of photothermal agents (PTAs) in cancer photothermal therapy (PTT) has shown promising results in clinical studies. The rapid degradation of PTAs may address safety concerns but usually limits the photothermal stability required for efficacious treatment. Conversely, PTAs with high photothermal stability usually degrade slowly. The solutions that address the balance between the high photothermal stability and rapid degradation of PTAs are rare. Here, we report that the inherent Cu2+-capturing ability of black phosphorus (BP) can accelerate the degradation of BP, while also enhancing photothermal stability. The incorporation of Cu2+ into BP@Cu nanostructures further enables chemodynamic therapy (CDT)-enhanced PTT. Moreover, by employing 64Cu2+, positron emission tomography (PET) imaging can be achieved for in vivo real-time and quantitative tracking. Therefore, our study not only introduces an "ideal" PTA that bypasses the limitations of PTAs, but also provides the proof-of-concept application of BP-based materials in PET-guided, CDT-enhanced combination cancer therapy.


Assuntos
Cobre/química , Hipertermia Induzida , Neoplasias/terapia , Fósforo/química , Fototerapia , Tomografia por Emissão de Pósitrons , Animais , Morte Celular , Linhagem Celular Tumoral , Terapia Combinada , Cobre/farmacocinética , Humanos , Íons , Camundongos , Nanoestruturas/química , Nanoestruturas/ultraestrutura , Oligopeptídeos/química , Fósforo/farmacocinética , Polietilenoglicóis/química , Espectrofotometria Ultravioleta , Nanomedicina Teranóstica
18.
Nat Commun ; 11(1): 3178, 2020 06 23.
Artigo em Inglês | MEDLINE | ID: mdl-32576814

RESUMO

Sophisticated mechanically interlocked molecules (MIMs) with interesting structures, properties and applications have attracted great interest in the field of supramolecular chemistry. We herein report a highly efficient self-assembly of heterometallic triangular necklace 1 containing Cu and Pt metals with strong antibacterial activity. Single-crystal X-ray analysis shows that the finely arranged triangular necklace 1 has two racemic enantiomers in its solid state with intriguing packing motif. The superior antibacterial activity of necklace 1 against both standard and clinically drug-resistant pathogens implies that the presence of Cu(I) center and platinum(II) significantly enhance the bacterium-binding/damaging activity, which is mainly attributed to the highly positively charged nature, the possible synergistic effect of heterometals in the necklace, and the improved stability in culture media. This work clearly discloses the structure-property relationships that the existence of two different metal centers not only facilitates successful construction of heterometallic triangular necklace but also endows it with superior nuclease properties and antibacterial activities.


Assuntos
Antibacterianos/química , Antibacterianos/farmacologia , Compostos Organometálicos/química , Compostos Organometálicos/farmacologia , Bactérias/efeitos dos fármacos , Cobre/química , Cristalografia por Raios X , Clivagem do DNA/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Espectroscopia de Ressonância Magnética , Testes de Sensibilidade Microbiana , Modelos Moleculares , Estrutura Molecular , Platina/química , Estereoisomerismo
19.
Ecotoxicol Environ Saf ; 201: 110858, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32563161

RESUMO

This work presents the research on the treatment of an anthraquinone derivatives of disperse dye Blue SI from aqueous solution using aluminium for the optimization of operational parameters like pH, current density, addition of electrolyte, contact time for the color removal efficiency (CRE) and the results are compared with the performance of copper electrodes in electrocoagulation (EC). The parameters for maximum CRE was found with Al at current density 40 Am-2, time 10 min at pH 7, and for Cu at 60 Am-2 15 min, at pH 6 were optimized. The characterization of the treated water using HPLC, MS studies revealed intermediate compounds. From the XPS analysis of the sludge obtained, the mechanism of EC was deduced. Treated aqueous solution was studied for its phytotoxicity with Vigna radiata and ecotoxicity studies were conducted on Artemia salina to study the toxicity effect of the intermediatory products in the treated dye solution. Blue SI dye aqueous solution treated with aluminium electrodes shows no or lesser toxicity in plants as well as in ecotoxic study compared with copper electrodes.


Assuntos
Alumínio/química , Antraquinonas/análise , Cobre/química , Técnicas Eletroquímicas/métodos , Poluentes Químicos da Água/análise , Purificação da Água/métodos , Animais , Antraquinonas/química , Antraquinonas/toxicidade , Artemia/efeitos dos fármacos , Eletrodos , Floculação , Concentração de Íons de Hidrogênio , Esgotos/química , Vigna/efeitos dos fármacos , Águas Residuárias/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/toxicidade
20.
Chemosphere ; 257: 127294, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32535362

RESUMO

Sulfonamide antibiotics (SAs) are widely used in veterinary medicine but are poorly metabolized in biological systems; thus, they can cause a selective pressure to promote the proliferation of antibiotic resistant pathogens and threaten human health. Persulfate (PS)-based advanced oxidation processes (AOPs) have been applied for SA degradation, but using transition metal ions as PS activators is relatively limited. In this study, sulfamethazine (SMZ) was used as a model SA to evaluate the performance of a Cu2+ -activated PS system. Cu2+-PS exhibited better SMZ removal than other metal ions, and 25 mg/L SMZ can be degraded in the presence of 0.2 mM Cu2+ and 2.5 g L-1 PS within 120 min. Various anions inhibited SMZ degradation to different degrees except HCO3-. Among the cations, Fe3+ significantly inhibited SMZ removal, while Ni2+ increased the removal rate. High concentrations of humic acid and protein also increased the degradation rate of SMZ. Radical and singlet oxygen quenching experiments, together with the results of electron spin-resonance spectroscopy (ESR), showed that the main active species generated from Cu2+-PS are SO4·- and ·OH. The degradation pathway of SMZ was identified through HPLC-HRMS. Direct SO4·- and ·OH oxidation products of SMZ were not found, suggesting that the complex formed between Cu2+ and SMZ may affect the fate of SMZ. On the other hand, the efficiency and selectivity of Cu2+-PS against different SAs were confirmed. Overall, this study provides a facile and effective method for SMZ and other SA removal.


Assuntos
Cobre/química , Sulfametazina/química , Sulfatos/química , Poluentes Químicos da Água/química , Antibacterianos , Humanos , Substâncias Húmicas , Oxirredução , Poluentes Químicos da Água/análise
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