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1.
Food Chem ; 455: 139918, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38824727

RESUMO

Herein, a novel FeCoNi(b)-800 ternary metal nanoalloy was uniformly mixed with reduced graphene oxide (RGO) to synthesize the FeCoNi(b)-800@RGO(2:1) composite. The addition of RGO not only stopped the accumulation of FeCoNi(b)-800 alloy, but also heightened the electrocatalytic activity of composite. Particularly, the FeCoNi(b)-800@RGO(2:1) composite displayed the significantly strong electrocatalytic capacity for the reduction of roxarsone (ROX). Furthermore, the FeCoNi(b)-800@RGO(2:1) composite possessed enough porosity and metal catalytic sites, facilitating the transport and electrochemical reduction of the ROX. Thus, the FeCoNi(b)-800@RGO(2:1) composite modified glassy carbon electrode (FeCoNi(b)-800@RGO(2:1)/GCE) showed the superb electrochemical detection effect for ROX with relatively wide working range (0.1-1500 µM) and low detection limit (0.013 µM). Importantly, the FeCoNi(b)-800@RGO(2:1)/GCE sensor could accurately determine the contents of ROX in actual pork, chicken, duck and egg samples, indicating that it had good suitability in food safety monitoring.


Assuntos
Galinhas , Técnicas Eletroquímicas , Contaminação de Alimentos , Grafite , Roxarsona , Grafite/química , Técnicas Eletroquímicas/instrumentação , Contaminação de Alimentos/análise , Animais , Roxarsona/química , Roxarsona/análise , Suínos , Ligas/química , Limite de Detecção , Ovos/análise , Carne/análise , Oxirredução , Eletrodos
2.
Anal Methods ; 16(18): 2857-2868, 2024 May 09.
Artigo em Inglês | MEDLINE | ID: mdl-38639051

RESUMO

The pentavalent arsenic compound roxarsone (RSN) is used as a feed additive in poultry for rapid growth, eventually ending up in poultry litter. Poultry litter contains chicken manure, which plays a vital role as an affordable fertilizer by providing rich nutrients to agricultural land. Consequently, the extensive use of poultry droppings serves as a conduit for the spread of toxic forms of arsenic in the soil and surface water. RSN can be easily oxidized to release highly carcinogenic As(III) and As(IV) species. Thus, investigations were conducted for the sensitive detection of RSN electrochemically by developing a sensor material based on lanthanum manganese oxide (LMO) and functionalized carbon nanofibers (f-CNFs). The successfully synthesised LMO/f-CNF composite was confirmed by chemical, compositional, and morphological studies. The electrochemical activity of the prepared composite material was examined using cyclic voltammetry (CV) and differential pulse voltammetry (DPV). The obtained results confirmed that LMO/f-CNF showed enhanced electrocatalytic activity and improved current response with a good linear range (0.01-0.78 µM and 2.08-497 µM, respectively), exhibiting a low limit of detection (LOD) of 0.004 µM with a high sensitivity of 13.24 µA µM-1 cm-2 towards the detection of RSN. The noteworthy features of LMO/f-CNF composite with its superior electrochemical performance enabled reliable reproducibility, exceptional stability and reliable practical application in the analysis of tap water and food sample, affording a recovery range of 86.1-98.87%.


Assuntos
Compostos de Cálcio , Técnicas Eletroquímicas , Lantânio , Nanofibras , Óxidos , Roxarsona , Titânio , Nanofibras/química , Lantânio/química , Óxidos/química , Técnicas Eletroquímicas/métodos , Roxarsona/química , Roxarsona/análise , Titânio/química , Compostos de Cálcio/química , Poluentes Químicos da Água/análise , Carbono/química , Limite de Detecção , Análise de Alimentos/métodos , Contaminação de Alimentos/análise , Animais , Compostos de Manganês/química
3.
Environ Int ; 185: 108517, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38401435

RESUMO

The organoarsenical feed additive roxarsone (ROX) is a ubiquitous threat due to the unpredictable levels of arsenic (As) released by soil bacteria. The earthworms representing soil fauna communities provide hotspots for As biotransformation genes (ABGs). Nonetheless, the role of gut bacteria in this regard is unclear. In this study, the changes in As speciation, bacterial ABGs, and communities were analyzed in a ROX-contaminated soil (50 mg/kg As in ROX form) containing the earthworm Eisenia feotida. (RE vs. R treatment). After 56 d, earthworms reduced the levels of both ROX and total As by 59 % and 17 %, respectively. The available As content was 10 % lower in the RE than in R treatment. Under ROX stress, the total ABG abundance was upregulated in both earthworm gut and soil, with synergistic effects observed following RE treatment. Besides, the enrichment of arsM and arsB genes in earthworm gut suggested that gut bacteria may facilitate As removal by enhancing As methylation and transport function in soil. However, the bacteria carrying ABGs were not associated with the ABG abundance in earthworm gut indicating the unique strategies of earthworm gut bacteria compared with soil bacteria due to different microenvironments. Based on a well-fit structural equation model (P = 0.120), we concluded that gut bacteria indirectly contribute to ROX transformation and As detoxification by modifying soil ABGs. The positive findings of earthworm-induced ROX transformation shed light on the role of As biomonitoring and bioremediation in organoarsenical-contaminated environments.


Assuntos
Arsênio , Oligoquetos , Roxarsona , Poluentes do Solo , Animais , Arsênio/análise , Roxarsona/farmacologia , Solo/química , Bactérias , Biotransformação , Poluentes do Solo/análise
4.
Chemosphere ; 345: 140558, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37898462

RESUMO

Roxarsone (3-nitro-4-hydroxyphenylarsonic acid, Rox), a widely used organoarsenical feed additive, can enter soils and be further biotransformed into various arsenic species that pose human health and ecological risks. However, the pathway and molecular mechanism of Rox biotransformation by soil microbes are not well studied. Therefore, in this study, we isolated a Rox-transforming bacterium from manure-fertilized soil and identified it as Pseudomonas chlororaphis through morphological analysis and 16S rRNA gene sequencing. Pseudomonas chlororaphis was able to biotransform Rox to 3-amino-4-hydroxyphenylarsonic acid (3-AHPAA), N-acetyl-4-hydroxy-m-arsanilic acid (N-AHPAA), arsenate [As(V)], arsenite [As(III)], and dimethylarsenate [DMAs(V)]. The complete genome of Pseudomonas chlororaphis was sequenced. PcmdaB, encoding a nitroreductase, and PcnhoA, encoding an acetyltransferase, were identified in the genome of Pseudomonas chlororaphis. Expression of PcmdaB and PcnhoA in E. coli Rosetta was shown to confer Rox(III) and 3-AHPAA(III) resistance through Rox nitroreduction and 3-AHPAA acetylation, respectively. The PcMdaB and PcNhoA enzymes were further purified and functionally characterized in vitro. The kinetic data of both PcMdaB and PcNhoA were well fit to the Michaelis-Menten equation, and nitroreduction catalyzed by PcMdaB is the rate-limiting step for Rox transformation. Our results provide new insights into the environmental risk assessment and bioremediation of Rox(V)-contaminated soils.


Assuntos
Arsênio , Pseudomonas chlororaphis , Roxarsona , Humanos , Pseudomonas chlororaphis/metabolismo , Solo , Acetiltransferases , RNA Ribossômico 16S/genética , RNA Ribossômico 16S/metabolismo , Escherichia coli/metabolismo , Arsênio/metabolismo , Biotransformação , Nitrorredutases/metabolismo
5.
Mater Horiz ; 10(12): 5782-5795, 2023 11 27.
Artigo em Inglês | MEDLINE | ID: mdl-37814901

RESUMO

The exploration of multifunctional materials and intelligent technologies used for fluorescence sensing and latent fingerprint (LFP) identification is a research hotspot of material science. In this study, an emerging crystalline luminescent material, Eu3+-functionalized hydrogen-bonded organic framework (Eu@HOF-BTB, Eu@1), is fabricated successfully. Eu@1 can emit purple red fluorescence with a high photoluminescence quantum yield of 36.82%. Combined with artificial intelligence (AI) algorithms including support vector machine, principal component analysis, and hierarchical clustering analysis, Eu@1 as a sensor can concurrently distinguish two carcinogens, roxarsone and aristolochic acid, based on different mechanisms. The sensing process exhibits high selectivity, high efficiency, and excellent anti-interference. Meanwhile, Eu@1 is also an excellent eikonogen for LFP identification with high-resolution and high-contrast. Based on an automatic fingerprint identification system, the simultaneous differentiation of two fingerprint images is achieved. Moreover, a simulation experiment of criminal arrest is conducted. By virtue of the Alexnet-based fingerprint analysis platform of AI, unknown LFPs can be compared with a database to identify the criminal within one second with over 90% recognition accuracy. With AI technology, HOFs are applied for the first time in the LFP identification field, which provides a new material and solution for investigators to track criminal clues and handle cases efficiently.


Assuntos
Inteligência Artificial , Roxarsona , Carcinógenos , Dermatoglifia
6.
Chemosphere ; 339: 139688, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37532198

RESUMO

In environmental systems, the soil is a principal route of contamination by various potentially toxic species. Roxarsone (RX) is an arsenic (V) organic compound used to treat parasitic diseases and as an additive for animal fattening. When the animal excretes RX, the residues may lead to environmental contamination. Due to their physicochemical properties, the soil's humic substances (HS) are important in species distribution in the environment and are involved in various specific interaction/adsorption processes. Since RX, an arsenic (V) compound, is considered an emerging contaminant, its interaction with HS was evaluated in simulated environmental conditions. The HS-RX interaction was analyzed by monitoring intrinsic HS fluorescence intensity variations caused by complexation with RX, forming non-fluorescent supramolecular complexes that yielded a binding constant Kb (on the order of 103). The HS-RX interaction occurred through static quenching due to complex formation in the ground state, which was confirmed by spectrophotometry. The process was spontaneous (ΔG < 0), and the predominant interaction forces were van der Waals and hydrogen bonding (ΔH < 0 and ΔS < 0), with an electrostatic component evidenced by the influence of ionic strength in the interaction process. Structural changes in the HS were verified by synchronized and 3D fluorescence, with higher variation in the region referring to the protein-like fraction. In addition, metal ions (except ions Cu(II)) favored HS-RX interaction. When interacting with HS, the RX epitope was suggested by 1H NMR, which indicated that the entire molecule interacts with the superstructure. An enzyme inhibition assay verified the ability to reduce the alkaline phosphatase activity of free and complexed RX (RX-HS). Finally, this work revealed the main parameters associated with HS and RX interaction in simulated environmental conditions, thus, providing data that may help our understanding of the dynamics of organic arsenic-influenced soils.


Assuntos
Arsênio , Roxarsona , Poluentes do Solo , Animais , Substâncias Húmicas/análise , Solo/química , Roxarsona/química , Poluentes do Solo/análise , Íons
7.
BMC Microbiol ; 23(1): 134, 2023 05 17.
Artigo em Inglês | MEDLINE | ID: mdl-37193944

RESUMO

BACKGROUND: Arsenic (As) with various chemical forms, including inorganic arsenic and organic arsenic, is the most prevalent water and environmental toxin. This metalloid occurs worldwide and many of its forms, especially arsenite [As(III)], cause various diseases including cancer. Organification of arsenite is an effective way for organisms to cope with arsenic toxicity. Microbial communities are vital contributors to the global arsenic biocycle and represent a promising way to reduce arsenite toxicity. METHODS: Brevundimonas sp. M20 with arsenite and roxarsone resistance was isolated from aquaculture sewage. The arsHRNBC cluster and the metRFHH operon of M20 were identified by sequencing. The gene encoding ArsR/methyltransferase fusion protein, arsRM, was amplified and expressed in Escherichia coli BL21 (DE3), and this strain showed resistance to arsenic in the present of 0.25-6 mM As(III), aresenate, or pentavalent roxarsone. The methylation activity and regulatory action of ArsRM were analyzed using Discovery Studio 2.0, and its functions were confirmed by methyltransferase activity analysis and electrophoretic mobility shift assays. RESULTS: The minimum inhibitory concentration of the roxarsone resistant strain Brevundimonas sp. M20 to arsenite was 4.5 mM. A 3,011-bp arsenite resistance ars cluster arsHRNBC and a 5649-bp methionine biosynthesis met operon were found on the 3.315-Mb chromosome. Functional prediction analyses suggested that ArsRM is a difunctional protein with transcriptional regulation and methyltransferase activities. Expression of ArsRM in E. coli increased its arsenite resistance to 1.5 mM. The arsenite methylation activity of ArsRM and its ability to bind to its own gene promoter were confirmed. The As(III)-binding site (ABS) and S-adenosylmethionine-binding motif are responsible for the difunctional characteristic of ArsRM. CONCLUSIONS: We conclude that ArsRM promotes arsenite methylation and is able to bind to its own promoter region to regulate transcription. This difunctional characteristic directly connects methionine and arsenic metabolism. Our findings contribute important new knowledge about microbial arsenic resistance and detoxification. Future work should further explore how ArsRM regulates the met operon and the ars cluster.


Assuntos
Arsênio , Arsenicais , Arsenitos , Roxarsona , Arsênio/metabolismo , Arsenitos/farmacologia , Arsenitos/metabolismo , Sequência de Bases , Escherichia coli/genética , Escherichia coli/metabolismo , Metilação , Roxarsona/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Arsenicais/metabolismo , Arsenicais/farmacologia , Óperon , Metiltransferases/genética , Metionina , Regulação Bacteriana da Expressão Gênica , Transativadores/genética
8.
J Hazard Mater ; 454: 131483, 2023 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-37116328

RESUMO

Roxarsone (3-nitro-4-hydroxyphenylarsonic acid, Rox(V)), an extensively used organoarsenical feed additive, enters soils through the application of Rox(V)-containing manure and further degrades to highly toxic arsenicals. Microplastics, as emerging contaminants, are also frequently detected in soils. However, the effects of microplastics on soil Rox(V) degradation are unknown. A microcosm experiment was conducted to investigate soil Rox(V) degradation responses to polyethylene (PE) microplastics and the underlying mechanisms. PE microplastics inhibited soil Rox(V) degradation, with the main products being 3-amino-4-hydroxyphenylarsonic acid [3-AHPAA(V)], N-acetyl-4-hydroxy-m-arsanilic acid [N-AHPAA(V)], arsenate [As(V)], and arsenite [As(III)]. This inhibition was likely driven by the decline in soil pH by PE microplastic addition, which may directly enhance Rox(V) sorption in soils. The decreased soil pH further suppressed the nfnB gene related to nitroreduction of Rox(V) to 3-AHPAA(V) and nhoA gene associated with acetylation of 3-AHPAA(V) to N-AHPAA(V), accompanied by a decrease in the relative abundance of possible Rox(V)-degrading bacteria (e.g., Pseudomonadales), although the diversity, composition, network complexity, and assembly of soil bacterial communities were largely influenced by Rox(V) rather than PE microplastics. Our study emphasizes microplastic-induced inhibition of Rox(V) degradation in soils and the need to consider the role of microplastics in better risk assessment and remediation of Rox(V)-contaminated soils.


Assuntos
Roxarsona , Roxarsona/química , Microplásticos , Plásticos , Solo/química , Polietileno
9.
Water Res ; 237: 119979, 2023 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-37098286

RESUMO

The conventional oxidation-adsorption methods are effective for the removal of roxarsone (ROX) but are limited by complicated operation, toxic residual oxidant and leaching of toxic metal ions. Herein, we proposed a new approach to improve ROX removal, i.e., using the FeS/sulfite system. Experimental results showed that approximately 100% of ROX (20 mg/L) was removed and more than 90% of the released inorganic arsenic (As(V) dominated) was adsorbed on FeS within 40 min. This FeS/sulfite system was a non-homogeneous activation process, and SO4·-, ·OH and 1O2 were identified as reactive oxidizing species with their contributions to ROX degradation being 48.36%, 27.97% and 2.64%, respectively. Based on density functional theory calculations and HPLC-MS results, the degradation of ROX was achieved by C-As breaking, electrophilic addition, hydroxylation and denitrification. It was also found that the released inorganic arsenic was adsorbed through a combination of outer-sphere complexation and surface co-precipitation, and the generated arsenopyrite (FeAsS), a precursor to ecologically secure scorodite (FeAsO4·2H2O), was served as the foundation for further inorganic arsenic mineralization. This is the first attempt to use the FeS/sulfite system for organic heavy metal removal, which proposes a prospective technique for the removal of ROX.


Assuntos
Arsênio , Roxarsona , Adsorção , Estudos Prospectivos , Oxirredução
10.
Chempluschem ; 88(4): e202300061, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36947010

RESUMO

Current treatments for infections caused by multidrug-resistant bacteria still remain challenging and therapeutic materials with high efficacy are of demand. Herein, a bactericidal nanocomposite was constructed by loading Roxarsone (ROX) onto nitrosylated mesoporous polydopamine (named mPDA@NO-ROX). The designed nanocomposite exhibited considerable photothermal effect and controlled NO and ROX co-delivery under the irradiation of near-infrared laser (NIR) to achieve enhanced chemo-photothermal antibacterial therapy. The in vitro antibacterial evaluation of the mPDA@NO-ROX demonstrated the effective elimination of the Gram-negative tetracycline-resistant Escherichia coil and Gram-positive methicillin-resistant Staphylococcus aureus under mild NIR irradiation compared to merely ROX loaded unmodified mPDA, indicating the NO enhanced chemo-photothermal therapy. In addition, the cytotoxicity experiments indicated that mPDA@NO-ROX exhibited only 5 % of hemolysis rate and high cell viability at 1 mg mL-1 against mammalian fibroblasts, suggesting the excellent biocompatibility. In conclusion, the mPDA@NO-ROX could be a promising candidate for anti-infection therapy of multidrug-resistant bacteria.


Assuntos
Infecções Bacterianas , Staphylococcus aureus Resistente à Meticilina , Nanocompostos , Nanopartículas , Roxarsona , Animais , Terapia Fototérmica , Nitritos , Antibacterianos/farmacologia , Mamíferos
11.
J Environ Sci (China) ; 129: 30-44, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36804240

RESUMO

The retention and fate of Roxarsone (ROX) onto typical reactive soil minerals were crucial for evaluating its potential environmental risk. However, the behavior and molecular-level reaction mechanism of ROX and its substituents with iron (hydr)oxides remains unclear. Herein, the binding behavior of ROX on ferrihydrite (Fh) was investigated through batch experiments and in-situ ATR-FTIR techniques. Our results demonstrated that Fh is an effective geo-sorbent for the retention of ROX. The pseudo-second-order kinetic and the Langmuir model successfully described the sorption process. The driving force for the binding of ROX on Fh was ascribed to the chemical adsorption, and the rate-limiting step is simultaneously dominated by intraparticle and film diffusion. Isotherms results revealed that the sorption of ROX onto Fh appeared in uniformly distributed monolayer adsorption sites. The two-dimensional correlation spectroscopy and XPS results implied that the nitro, hydroxyl, and arsenate moiety of ROX molecules have participated in binding ROX onto Fh, signifying that the predominated mechanisms were attributed to the hydrogen bonding and surface complexation. Our results can help to better understand the ROX-mineral interactions at the molecular level and lay the foundation for exploring the degradation, transformation, and remediation technologies of ROX and structural analog pollutants in the environment.


Assuntos
Roxarsona , Roxarsona/química , Compostos Férricos/química , Ferro , Solo/química , Minerais/química , Adsorção
12.
Int Immunopharmacol ; 114: 109527, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36700762

RESUMO

Hepatic fibrosis is a pathological change caused by chronic liver injury and self-repair, and it is the inevitable stage of the development of chronic liver disease to cirrhosis or even liver cancer. Activation of hepatic stellate cells (HSCs) is a core event in the development of liver fibrosis and blockage of the activation of HSCs has been shown to alleviate liver fibrosis. Roxarsone, an organoarsenic additive, with antibiotic effect, growth promotion and improving feed efficiency, is widely used in livestock and animal production. The purpose of this study was to evaluate the therapeutic effect of Roxarsone on liver fibrosis and explore the possible mechanism. We found that Roxarsone could inhibit transforming growth factor-ß1 (TGF-ß1) induced the activation of HSCs and weaken the migration ability. Moreover, Roxarsone administration significantly ameliorated CCl4-induced liver fibrosis in mice with improvement of liver function and decreases of deposition of extracellular matrix (ECM). Mechanism investigations revealed that Roxarsone specifically inhibited the activation of TGF-ß1/Smad signaling pathway, but had no effect on MAPK and PI3K/AKT pathways. These results suggest that Roxarsone has a protective effect on liver fibrosis which provides a new candidate for the treatment of liver fibrosis.


Assuntos
Roxarsona , Fator de Crescimento Transformador beta1 , Animais , Camundongos , Tetracloreto de Carbono , Células Estreladas do Fígado , Fígado/patologia , Cirrose Hepática/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Roxarsona/metabolismo , Roxarsona/farmacologia , Roxarsona/uso terapêutico , Transdução de Sinais , Proteínas Smad/metabolismo , Fator de Crescimento Transformador beta1/metabolismo
13.
J Hazard Mater ; 442: 130037, 2023 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-36179620

RESUMO

Plastic additives widely existed in plastic mulching films, but their roles in microplastics (MPs) derived from these plastics as vectors of pollutants were not clear. This work clarified the role of plastic additives on the sorption-desorption behaviors of four arsenic species (arsenite (As(Ⅲ)), arsenate (As(Ⅴ)), roxarsone (ROX), and p-arsanilic acid (p-ASA)) on/from virgin polyethylene (V-PE), white PE mulching film (W-PE, with Si-containing additives), and black PE mulching film (B-PE, with CaCO3 and TiO2 additives) MPs. The maximum sorption amounts of arsenic species on V-PE (3.33-20.10 mg/kg) and W-PE MPs (4.78-21.93 mg/kg) had no significant difference, while those on B-PE (43.02-252.19 mg/kg) facilitated by its additives were up to one order of magnitude greater than V-PE or W-PE (p < 0.05). Desorption hysteresis index (HI) indicated the irreversible arsenic sorption on three PE MPs, especially for B-PE containing additives that can co-precipitate and complex with arsenicals. The effects of pH, humic substances, and coexisting anions on arsenic sorption by B-PE were more obvious than that by V-PE or W-PE MPs, attributing to electrostatic interaction enhanced by CaCO3 and TiO2 additives. This work provides theoretical basis for migration of arsenic species on MPs containing plastic additives and their potential environmental risk assessment.


Assuntos
Arsênio , Arsenicais , Arsenitos , Poluentes Ambientais , Roxarsona , Poluentes Químicos da Água , Microplásticos , Plásticos/química , Arseniatos , Polietileno/química , Substâncias Húmicas , Ácido Arsanílico , Adsorção , Poluentes Químicos da Água/química
14.
J Environ Manage ; 328: 116945, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36512947

RESUMO

The contamination of organoarsenic is becoming increasingly prominent while SR-AOPs were confirmed to be valid for their remediation. This study has found that the novel metal/carbon catalyst (Fe/C-Mn) prepared by solid waste with hierarchical pores could simultaneously degrade roxarsone (ROX) and remove As(V). A total of 95.6% of ROX (20 mg/L) could be removed at the concentration of 1.0 g/L of catalyst and 0.4 g/L of oxidant in the Fe/C-Mn/PMS system within 90 min. The scavenging experiment and electrochemical test revealed that both single-electron and two-electron pathways contributed to the ROX decomposition. Spectroscopic analysis suggested the ROX has been successfully mineralized while As(V) was fixed with the surface Fe and Mn. Density functional theory (DFT) calculation and chromatographic analysis indicated that the As7, N8, O9 and O10 sites of ROX molecule were vulnerable to being attacked by nucleophilic, electrophilic and radical, resulting in the formation of several intermediates such as phenolic compounds. Additionally, the low metal leaching concentration during recycling and high anti-interference ability in various water matrices manifested the practicability of Fe/C-Mn/PMS system.


Assuntos
Roxarsona , Roxarsona/química , Roxarsona/metabolismo , Manganês , Carvão Vegetal , Metais , Eletrólitos
15.
Spectrochim Acta A Mol Biomol Spectrosc ; 289: 122213, 2023 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-36527969

RESUMO

The influence of Fe(III) on the interaction between roxarsone (ROX) and humic acid (HA) was investigated by multi-spectroscopic techniques. The fluorescence quenching experiment indicated that the fluorescence intensity of HA-ROX was quenched by Fe(III) through a static quenching process. Synchronous fluorescence spectra provided further information concerning the competitive combination between ROX and Fe(III) for HA. The results of the dialysis equilibrium experiment confirmed the existence of Fe(III) (0.05-0.1 mmol/L) promotes the combination of HA and ROX. Binding mechanisms were further characterized by FTIR spectroscopy, and the carboxyl functional group is involved in the binding process of HA/Fe/ROX. In addition, acidic and neutral conditions are more conducive to the combination of ROX and HA/Fe than alkaline conditions. The above discussion is of great significance in understanding the environmental fate of ROX under the coexistence of Fe(III) and HA.


Assuntos
Roxarsona , Roxarsona/química , Substâncias Húmicas/análise , Compostos Férricos/química , Diálise Renal , Espectroscopia de Infravermelho com Transformada de Fourier
16.
ACS Appl Mater Interfaces ; 14(43): 48658-48674, 2022 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-36274222

RESUMO

Frequent use of antibiotics and the growth of industry lead to the pollution of several natural resources which is one of the major consequences for fatality to human health. Exploration of smart sensing materials is highly anticipated for ultrasensitive detection of those hazardous organics. The robust porous hydrogen bonded network encompassing a free-NH2 moiety, Zn(II)-based metal-organic framework (MOF) (1), is used for the selective detection of antibiotics and toxic oxo-anions at the ppb level. The framework is able to detect the electronically dissimilar antibiotic sulfadiazine and nitrofurazone via fluorescence "turn-on" and "turn-off" processes, respectively. The antibiotic-triggered reversible fluoro-switching phenomena (fluorescence "on-off-on") are also observed by using the fluorimetric method. An extensive theoretical investigation was performed to establish the fluoro-switching response of 1, triggered by a class of antibiotics and also the sensing of oxo-anions. This investigation reveals that the interchange of the HOMO-LUMO energy levels of fluorophore and analytes is responsible for such a fluoro-switchable sensing activity. Sensor 1 showed the versatile detection ability which is reflected by the detection of a carcinogenic nitro-group-containing drug "roxarsone". In view of the sustainable environment along with quick-responsive merit of 1, an in situ MOF gel composite (1@CS; CS = corn starch) is prepared using 1 and CS due to its useful potential features such as biocompatibility, toxicologically innocuous, good flexibility, and low commercial price. The MOF composite exhibited visual detection of the above analytes as well as antibiotic-triggered reversible fluoro-switchable colorimetric "on-off-on" response. Therefore, 1@CS represents a promising smart sensing material for monitoring of the antibiotics and oxo-anions, particularly appropriate for the real-field analysis of carcinogenic drug molecule "roxarsone" in food specimens.


Assuntos
Estruturas Metalorgânicas , Roxarsona , Materiais Inteligentes , Humanos , Amido , Antibacterianos , Zea mays , Ânions , Carcinogênese , Carcinógenos
17.
Inorg Chem ; 61(41): 16370-16379, 2022 Oct 17.
Artigo em Inglês | MEDLINE | ID: mdl-36184926

RESUMO

Nanomaterials have versatile properties owing to their high surface-to-volume ratio and can thus be used in a variety of applications. This work focused on applying a facile hydrothermal strategy to prepare praseodymium vanadate nanoparticles due to the importance of nanoparticles in today's society and the fact that their synthesis might be a challenging endeavor. The structural and morphological characterizations were carried out to confirm the influence of the optimizations on the reaction's outcomes, which revealed praseodymium vanadate (PrVO4) with a tetragonal crystal system. In this regard, the proposed development of electrochemical sensors based on the PrVO4 nanocatalyst for the real-time detection of arsenic drug roxarsone (RXS) is a primary concern. The detection was measured by amperometric (i-t) signals where PrVO4/SPCE, as a new electrochemical sensing medium for RXS detection, increased the sensitivity of the sensor to about ∼2.5 folds compared to the previously reported ones. In the concentration range of 0.001-551.78 µM, the suggested PrVO4/SPCE sensor has a high sensitivity for RXS, with a detection limit of 0.4 nM. Furthermore, the impact of several selected potential interferences, operational stability (2000 s), and reproducibility measurements have no discernible effect on RXS sensing, making it the ideal sensing device feasible for technical analysis. The real-time analysis reveals the excellent efficiency and reliability of the prosed sensor toward RXS detection with favorable recovery ranges between ±97.00-99.66% for chicken, egg, water, and urine samples.


Assuntos
Arsênio , Nanopartículas , Roxarsona , Técnicas Eletroquímicas , Eletrodos , Limite de Detecção , Praseodímio , Reprodutibilidade dos Testes , Roxarsona/análise , Roxarsona/química , Vanadatos , Água
18.
Chemosphere ; 308(Pt 2): 136326, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36084835

RESUMO

Organoarsenical antibiotics pose a severe threat to the environment and human health. In aquatic environment, dissolved organic matter (DOM)-mediated photochemical transformation is one of the main processes in the fate of organoarsenics. Dicarbonyl is a typical redox-active moiety in DOM. However, the knowledge on the photoconversion of organoarsenics by DOM, especially the contributions of dicarbonyl moieties is still limited. Here, we systematically investigated the photochemical transformation of three organoarsenics with the simplest ß-diketone, acetylacetone (AcAc), as a model dicarbonyl moiety of DOM. The presence of AcAc significantly enhanced the photochemical conversion of roxarsone (ROX), whereas only minor effects were observed for 3-amino-4-hydroxyphenylarsonic acid (HAPA) and arsanilic acid (ASA), because the latter two (with an amino (-NH2) group) are more photoactive than ROX (with a nitro (-NO2) group). The results demonstrate that AcAc was a potent photo-activator and the reduction of -NO2 to -NH2 might be a rate-limiting step in the phototransformation of ROX. At a 1:1 M ratio of AcAc to ROX, the photochemical transformation rate of ROX was increased by 7 folds. In O2-rich environment, singlet oxygen, peroxide radicals, and ·OH were the main reactive species that led to the breakage of the C-As bond in ROX and the oxidation of the released arsono group to arsenate, whereas the triplet-excited state of AcAc (3AcAc*) and carbon-centered radicals from the photolysis of AcAc dominated in the reductive transformation of ROX. In anoxic environment, 3-amino-4-hydroxyphenylarsonic acid was one of the main reductive transformation intermediates of ROX, whose photolysis rate was about 35 times that of ROX. The knowledge obtained here is of great significance to better understand the fate of organoarsenics in natural environment.


Assuntos
Roxarsona , Poluentes Químicos da Água , Antibacterianos , Ácido Arsanílico , Arseniatos , Carbono , Humanos , Dióxido de Nitrogênio , Oxirredução , Pentanonas , Peróxidos , Fotólise , Roxarsona/química , Oxigênio Singlete , Poluentes Químicos da Água/análise
19.
Toxicology ; 478: 153290, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35985552

RESUMO

Roxarsone, an organoarsenic compound used in poultry industry to increase weight gain, is widely used as a feed additive in some developing countries. Roxarsone has a low absorption rate and is mostly excreted with feces, which could pose a risk to human health through environmental and animal food routes. Roxarsone has been demonstrated to have tumor-promoting and proangiogenic effects. Herein, we report the role of VEGFR2/mTOR/S6K1 signaling in roxarsone-promoted vessel endothelial cell growth and angiogenesis in the Matrigel plug model and the mouse B16 cell tumor transplantation model. In angiogenesis-related experiments in vitro, 1.0 µM roxarsone significantly increased the activity, proliferation, migration, and tube formation of rat vascular endothelial cells. In addition, 1.0 µM roxarsone upregulated the protein levels of mTOR, phosphorylated mTOR, S6K1, and phosphorylated S6K1 and significantly increase the expression of Mtor and S6k1 mRNA. Rapamycin and SU5416 significantly inhibited the effects of 1.0 µM roxarsone on cell growth. Furthermore, the weight, volume, and CD31 expression of B16-F10 xenografts and Matrigel plugs in mice were upregulated by 25 mg/kg roxarsone. The protein and mRNA levels of mTOR, S6K1 and its phosphorylated protein were significantly increased in the roxarsone treatment group in xenografts. SU5416 and a short hairpin RNA targeting Vegfr2 significantly reduced roxarsone-promoted xenograft and Matrigel plug growth. In summary, this study indicated that the VEGFR2/mTOR/S6K1 signaling plays a regulatory role in roxarsone-mediated promotion angiogenesis and enhanced tumor growth.


Assuntos
Roxarsona , Animais , Proliferação de Células , Células Endoteliais , Células Endoteliais da Veia Umbilical Humana/patologia , Humanos , Camundongos , Neovascularização Patológica/patologia , RNA Mensageiro/metabolismo , Ratos , Roxarsona/metabolismo , Roxarsona/toxicidade , Serina-Treonina Quinases TOR/metabolismo
20.
Int J Mol Sci ; 23(10)2022 May 17.
Artigo em Inglês | MEDLINE | ID: mdl-35628430

RESUMO

Arsenic (As), distributed widely in the natural environment, is a toxic substance which can severely impair the normal functions in living cells. Research on the genetic determinants conferring functions in arsenic resistance and metabolism is of great importance for remediating arsenic-contaminated environments. Many organisms, including bacteria, have developed various strategies to tolerate arsenic, by either detoxifying this harmful element or utilizing it for energy generation. More and more new arsenic resistance (ars) determinants have been identified to be conferring resistance to diverse arsenic compounds and encoded in ars operons. There is a hazard in mobilizing arsenic during gold-mining activities due to gold- and arsenic-bearing minerals coexisting. In this study, we isolated 8 gold enrichment strains from the Zijin gold and copper mine (Longyan, Fujian Province, China) wastewater treatment site soil, at an altitude of 192 m. We identified two Brevundimonas nasdae strains, Au-Bre29 and Au-Bre30, among these eight strains, having a high minimum inhibitory concentration (MIC) for As(III). These two strains contained the same ars operons but displayed differences regarding secretion of extra-polymeric substances (EPS) upon arsenite (As(III)) stress. B. nasdae Au-Bre29 contained one extra plasmid but without harboring any additional ars genes compared to B. nasdae Au-Bre30. We optimized the growth conditions for strains Au-Bre29 and Au-Bre30. Au-Bre30 was able to tolerate both a lower pH and slightly higher concentrations of NaCl. We also identified folE, a folate synthesis gene, in the ars operon of these two strains. In most organisms, folate synthesis begins with a FolE (GTP-Cyclohydrolase I)-type enzyme, and the corresponding gene is typically designated folE (in bacteria) or gch1 (in mammals). Heterologous expression of folE, cloned from B. nasdae Au-Bre30, in the arsenic-hypersensitive strain Escherichia coli AW3110, conferred resistance to As(III), arsenate (As(V)), trivalent roxarsone (Rox(III)), pentavalent roxarsone (Rox(V)), trivalent antimonite (Sb(III)), and pentavalent antimonate (Sb(V)), indicating that folate biosynthesis is a target of arsenite toxicity and increased production of folate confers increased resistance to oxyanions. Genes encoding Acr3 and ArsH were shown to confer resistance to As(III), Rox(III), Sb(III), and Sb(V), and ArsH also conferred resistance to As(V). Acr3 did not confer resistance to As(V) and Rox(V), while ArsH did not confer resistance to Rox(V).


Assuntos
Arsênio , Arsenitos , Caulobacteraceae , Roxarsona , Arsênio/metabolismo , Arsenitos/toxicidade , Bactérias/metabolismo , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Caulobacteraceae/metabolismo , Escherichia coli/metabolismo , Ácido Fólico/metabolismo , Ouro/metabolismo , Roxarsona/metabolismo , Roxarsona/farmacologia
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