Nitroaromatic Compounds Research Articles

Co–Ni nanoparticle supported on heteroatom-doped carbon derived from garlic powder and eutectic solvent: Its application in Nitroarenes reduction

This paper presents the synthesis of a novel heterogeneous catalyst, PSN-C600-Co2:Ni1, designed for the hydrogenation of nitroaromatic compounds. The catalyst is a porous carbon substrate triply doped with nitrogen, sulfur, and phosphorus, incorporating bimetallic Co and Ni nanoparticles. A natural precursor, garlic biochar, and a biodegradable eutectic solvent were used in the synthesis. Various characterization techniques, including Scanning Electron Microscope (SEM), X-Ray Energy Diffraction Spectroscopy (EDX), Elemental Mapping Measurements (MAP), Thermogravimetric Analysis (TGA), X-Ray Diffraction (XRD), Infrared Spectrometer (FTIR), Transmission Electron Microscope (TEM), Raman Spectroscopy, and Nitrogen Adsorption and Desorption Pattern (N2 adsorption-desorption isotherm), were utilized to examine the features and properties of the synthesized PSN-C600-Co2:Ni1 catalyst.

Evidence for Cytotoxicity and Mitochondrial Dysfunction in Human Lung Cells Exposed to Biomass Burning Aerosol Constituents: Levoglucosan and 4-Nitrocatechol

Biomass burning (BB) emissions are one of the largest sources of carbonaceous aerosol, posing a significant risk as an airway irritant. Important BB markers include wood pyrolysis emissions, such as levoglucosan (LG) that is an anhydrous sugar bearing a six-carbon ring structure (i.e., 1,6-anhydro-β-D-glucopyranose). Atmospheric chemical aging of BB-derived aerosol (BBA) in the presence of nitrogen oxides (NOx) can yield nitro-aromatic compounds, including 4-nitrocatechol (4NC). There is building evidence that NOx-mediated chemical aging of BBA poses a more serious exposure effect than primary pyrolysis emissions. This study provides a comparative toxicological assessment following the exposure to important BBA marker compounds in human lung cells (i.e., A549 and BEAS-2B) to determine whether aromatic 4NC is more toxic than BBA-bound anhydrous carbohydrate (i.e., LG). We determined inhibitory concentration-50 (IC50) and examined reactive oxygen species (ROS) changes, mitochondrial dysfunction, and apoptosis induction in the two cell lines following exposure to LG and 4NC in a dose-response manner. In the BEAS-2B cells, estimated IC50 values for 4NC were 33 and 8.8 μg mL-1, and for LG were 2546 and ∼ 3 × 107 μg mL-1 at 24 h and 48 h of exposure, respectively. A549 cells exhibited a much higher IC50 value than BEAS-2B cells. LG exposures resulted in mitochondrial stress with viability inhibition, but cells recovered with increasing exposure time. 4NC exposures at 200 μg mL-1 resulted in the induction of apoptosis at 6 h. Mitochondrial dysfunction and ROS imbalance induced the intrinsic apoptotic pathway induction following 4NC exposures. While increased ROS is caused by LG exposure in lung cells, 4NC is a marker of concern during BB emissions, as we observed apoptosis and high mitochondrial ROS in both lung cells at atmospherically-relevant aerosol concentrations. It may be associated with higher airway or inhalation pathologies in higher BBA emissions, such as wildfires or during wood combustion.

Visible-light induced effective and sustainable remediation of nitro organics pollutants using Pd-doped ZnO nanocatalyst

Nitroaromatic compounds represent a class of highly toxic pollutants discharged into aquatic environments by various industrial activities, posing significant threats to ecological integrity and human health due to their persistent and hazardous nature. In this study, Pd-doped ZnO nanoparticles were investigated as a potential solution for the degradation of nitro organics, offering heightened photocatalytic efficacy and prolonged stability. The synthesis of Pd-doped ZnO NPs was achieved via the hydrothermal method, with subsequent analysis through XRD spectra and XPS confirming successful Pd doping within the ZnO matrix. Characterization through FESEM and HRTEM unveiled the heterogeneous morphologies of both undoped and Pd-doped ZnO nanoparticles. Additionally, UV–vis and PL spectroscopy provided insights into the optical properties, chemical bonding, and defect structures of the synthesized Pd-doped ZnO NPs. Pd doping induces a redshift in ZnO’s absorption spectra, reducing the bandgap from 3.12 to 2.94 eV as Pd concentration rises from 0 to 0.2 wt.%. The photocatalytic degradation, following pseudo-first-order kinetics, achieved 90% nitrobenzene abatement (200 µg/L, pH 7) under visible light within 320 min with a catalyst loading of 16 µg/mL. The photocatalytic efficacy of 0.08 wt% Pd-doped ZnO (k = 0.058 min⁻1) exhibited a 25-fold enhancement compared to bare ZnO (k = 3.1 × 10–4 min-1). Subsequent quenching and ESR experiments identified hydroxyl radicals (OH•) as the predominant active species in the degradation mechanism. Mass spectrometry analysis unveiled potential breakdown intermediates, illuminating a plausible degradation pathway. The investigated Pd-doped ZnO nanoparticles demonstrated reusability for up to five successive treatment cycles, offering a sustainable solution to nitro organics contamination challenges.

Two Stable Pillar-Layered Zn-LMOFs for Highly Fluorescence Sensing of Inorganic Pollutants and Nitro Aromatic Compounds in Water.

Luminescent metal-organic frameworks (LMOFs) are a potential class of functional materials for the photoluminescent detection of a wide range of analytes as well as for the detection of pollutants in wastewater. Herein, by using the pillar-layered strategy, two new luminescence Zn-LMOFs (JLU-MOF222 and JLU-MOF223) were successfully solvothermal synthesized. The 2D layers are both consisting of Zn2+ and TPHC [TPHC = (1,1':2',1″-terphenyl)-3,3″,4,4',4″,5'-hexacarboxylic acid] ligands and then pillared by the different N-donor ligands to form the 3D Zn-LMOFs with fsh topology. Benefiting from the uncoordinated carboxylate sites, uncoordinated N atom, or -NH2 group in the pillaring ligands and excellent stability in pH = 2-13 aqueous phase, JLU-MOF222 and JLU-MOF223 not only can sensitively detect trace amounts of inorganic pollutants (Fe3+, Cr2O72-) and nitro aromatic compounds TNP and 2,4-DNP (TNP = 2,4,6- trinitrophenol, 2,4-DNP = 2,4-dinitrophenol) through luminescence quenching but also exhibit high selectivity of other anti-interference competing analytes. The two new Zn-LMOFs can be used as potential luminescent sensors for pollutant detection in water due to their high KSV and low limit of detection (LOD).

Sustainable synthesis of multifaceted copper oxide nanoparticles from Euphorbia tirucalli: Unveiling antimicrobial and catalytic potential

This work presents Euphorbia tirucalli mediated green synthesis of multi-purpose copper oxide nanoparticles (ET@CuO-NPs) exhibiting enhanced antimicrobial activity. These plant extract capped nanoparticles were characterized using sophisticated techniques such as FTIR, Raman, UV–Vis, SEM, HR-TEM, DLS, zeta potential, XPS and XRD. A uniform rod-shaped morphology was observed in HR-TEM images with size around 50 nm. Antibacterial and antifungal activity was investigated by agar well diffusion method. The bactericidal action was confirmed by zone of inhibition of 28 mm and 34 mm respectively against gram-negative and a gram-positive bacterium. The nanoparticles also show excellent antioxidant activity via free radical scavenging by DPPH. The scope of ET@CuO-NPs was extended to catalytic reduction of nitroaromatic compounds into their corresponding amino derivatives. The reduction of 4-nitrophenol, a model nitroaromatic pollutant could be completed within just 6 min with a recycling efficiency of 8 cycles. Thus, the multifaceted ET@CuO-NPs exhibited diverse therapeutic and catalytic potential.

Selectivity Modulation of Multistep Reduction Reactions by Gold Nanoclusters

The selective synthesis of valuable azo‐ and azoxyaromatic chemicals via transfer coupling of nitroaromatic compounds has been achieved by fine‐tuning the catalyst structure. Here, a direct method to modulate nitrobenzene reduction and selectively alter the product from azobenzene to azoxybenzene by employing the size effect of Au is reported. Au nanoclusters (NCs) with smaller sizes embedded in ZIF‐8 controllably converted nitrobenzene into azoxybenzene, while supported Au nanoparticles (NPs) catalyzed nitrobenzene reduction to azobenzene. X‐ray photoelectron spectroscopy (XPS) and Diffuse reflectance infrared Fourier transform spectroscopy on CO adsorption (CO‐DRIFTS) of Au NC/ZIF‐8 revealed a higher valence state and a lower electron density of Au than that of Au NP/ZIF‐8, combined with the desorption of azoxybenzene from the Au NC and Au NP surface, suggesting that the Au NCs with lower electron density exhibit stronger adsorption. Density functional theory (DFT) calculations and charge density difference maps indicated that azoxybenzene bonded to Au NC/ZIF‐8 with greater adsorption energy, resulting in more electron transfer between azoxybenzene and the generated Au sites, which inhibited further reduction of azoxybenzene and resulted in high azoxybenzene selectivity. The application of the size effect of Au particles to regulate nitrobenzene transfer coupling provided new insights into the structure‐selectivity relationships.

Selectivity Modulation of Multistep Reduction Reactions by Gold Nanoclusters.

The selective synthesis of valuable azo- and azoxyaromatic chemicals via transfer coupling of nitroaromatic compounds has been achieved by fine-tuning the catalyst structure. Here, a direct method to modulate nitrobenzene reduction and selectively alter the product from azobenzene to azoxybenzene by employing the size effect of Au is reported. Au nanoclusters (NCs) with smaller sizes embedded in ZIF-8 controllably converted nitrobenzene into azoxybenzene, while supported Au nanoparticles (NPs)catalyzed nitrobenzene reduction to azobenzene. X-ray photoelectron spectroscopy (XPS) and Diffuse reflectance infrared Fourier transform spectroscopy on CO adsorption (CO-DRIFTS) of Au NC/ZIF-8 revealed a higher valence state and a lower electron density of Au than that of Au NP/ZIF-8, combined with the desorption of azoxybenzene from the Au NC and Au NP surface, suggesting that the Au NCs with lower electron density exhibit stronger adsorption. Density functional theory (DFT) calculations and charge density difference maps indicated that azoxybenzene bonded to Au NC/ZIF-8 with greater adsorption energy, resulting in more electron transfer between azoxybenzene and the generated Au sites, which inhibited further reduction of azoxybenzene and resulted in high azoxybenzene selectivity. The application of the size effect of Au particles to regulate nitrobenzene transfer coupling provided new insights into the structure-selectivity relationships.

N,S‐Doped Ordered Mesoporous Carbon: An Effective Catalyst for the Formylation of Anilines and Stabilization of Pd Nanoparticles to Catalyze the Hydrogenation of Nitroarenes

AbstractN,S‐Doped highly ordered mesoporous carbon (N,S‐doped OMC) material was constructed by the nanocasting methodology using egg yolk with a high content of amino acids as a carbon precursor and SBA‐15 as a hard template, followed by carbonization at 500 °C under an N2 atmosphere, and then aqueous alkaline‐induced removal of the silica moiety of the SBA‐15 template. Prepared N,S‐doped OMC material efficiently catalyzed the formylation of various substituted anilines using DMF as a formylating agent in water, to afford N‐formylaniline derivatives in high to excellent yields. Also, as‐prepared N,S‐doped OMC was used to immobilize and stabilize the Pd nanoparticles in order to synthesize Pd@OMC material, which was used as an efficient catalyst for the hydrogenation of nitroaromatic compounds to the corresponding aniline derivatives. Nitroaromatic compounds are considered to be highly toxic water contaminant compounds, and their removal from wastewater by the hydrogenation is an interesting method. Furthermore, Pd@OMC catalyzed one‐pot tandem hydrogenation of nitrobenzene/formylation reactions was investigated, which gave corresponding N‐formyl aniline in high yield. Synthesized OMC and Pd@OMC were characterized using X‐ray diffraction (XRD), Brunauer‐Emmett‐Teller (BET), scanning electron microscopy (SEM), energy‐dispersive X‐ray spectroscopy (EDS), and transmission electron microscopy (TEM) analysis.

Bifunctional In-MOFs for Selective and Sensitive Detection of Trace Nitrobenzene Compounds in Water and Possessing High Proton Conductivity.

With the escalating prevalence of terrorism and global environmental pollution, nitroaromatic compounds (NACs) have increasingly come into focus as the primary culprit. To counter these challenges, it is imperative to develop simple and efficient methods for detecting NACs. Considering the electron-deficient structure of NAC molecules, this paper constructed a novel three-dimensional In-MOF with permanent porosity using electron-rich organic molecules 4'-[1,2,2-tris(3',5'-dicarboxy[1,1'-biphenyl]-4-yl)ethenyl]-[1,1'-biphenyl]-3,5-dicarboxylic acid (H8ETTB) for fluorescence detection by photoinduced electron transfer. The results indicated that In-ETTB can sensitively detect trace NACs in water. In-ETTB exhibited the best detection performance for 3-NP, achieving a Ksv value of 8.75 × 104 M-1 with a limit of detection of 0.27 μΜ in aqueous solution; this belongs to a relatively high level among the reported metal organic framework (MOF) materials. Subsequently, anti-interference experiments revealed that In-ETTB exhibits strong specificity fluorescence recognition of NACs, and it could still maintain its structural integrity and fluorescence emission intensity even after 7 cycles of testing. We confirmed that the fluorescence detection of NACs was due to a combined effect of competitive absorption and photoinduced electron transfer through experimental collaboration DFT calculations in detail. Meanwhile, the proton conductivity reached 2.45 × 10-2 S·cm-1 at 98% relative humidity and 90 °C, which is also a high level in MOFs. This work provides a universal method theoretical basis for designing NAC detectors with practical application prospects.

White‐Light‐Emitting Ln‐MOF as Luminescent Probe for Selective Detection of Nitroaromatic Compounds

AbstractMetal‐organic frameworks (MOFs) as an efficient and convenient sensing material for environmental pollutants have attracted widespread attention in recent years. Here in, we synthesized a series of lanthanide co‐doping MOFs, EuxTb1‐x‐MOFs (x=0, 0.005, 0.00667, 0.01, 0.02 and 1) under solvothermal conditions. The luminescence colors can be adjusted by changing metal molar mass ratios and altering excitation wavelength. Fortunately, a near white‐light‐emitting material Eu0.01Tb0.99‐MOF was obtained under the excitation at 350 nm, whose CIE coordinates of (0.3444, 0.3409) are very close to standard white light coordinates (0.3333, 0.3333). We further studied the fluorescence sensing performances of Eu‐MOF, Tb‐MOF and Eu0.01Tb0.99‐MOF towards NACs. The results indicate that all MOFs can selectively detect 4‐nitroaniline, 4‐nitrophenol and 2‐nitrophenol with good sensitivity and recyclability.

Tracking dissociation pathways of nitrobenzene via mega-electron-volt ultrafast electron diffraction

Abstract As the simplest nitroaromatic compound, nitrobenzene is an interesting model system to explore the rich photochemistry of nitroaromatic compounds. Previous investigations of nitrobenzene’s photochemical dynamics have probed structural and electronic properties. These investigations paint, at times, a convoluted and sometimes contradictory description of the photochemical landscape. We investigate the ultrafast dynamics of nitrobenzene triggered by photoexcitation at 267 nm for the first time using a structural probe with femtosecond time resolution. Our probe complements previous measurements of nitrobenzene’s electronic structure evolution and aids in determining the photochemical dynamics with less ambiguity. We employ megaelectronvolt ultrafast electron diffraction to follow nitrobenzene’s structural evolution within the first 5 ps after photoexcitation. We observe ground state recovery within 160 ± 60 fs through nonadiabatic dynamics. Based on comparisons of the experimental signal with molecular dynamics simulations, we exclude a significant population of the triplet manifold. Furthermore, we do not observe fragmentation of nitrobenzene within the investigated time window, which indicates that previously observed photofragmenation reactions take place in the vibrationally “hot” ground state on timescales considerably beyond 5 ps.

Advanced-Functional-Material-Modified Electrodes for the Monitoring of Nitrobenzene: Progress in Nitrobenzene Electrochemical Sensing

Nitrobenzene (NB) is one of the nitro-aromatic compounds that is extensively used in various chemical industries. Despite its potential applications, NB is considered to be a toxic compound that has significant hazardous effects on human health and the environment. Thus, it can be said that the NB level should be monitored to avoid its negative impacts on human health. In this vein, the electrochemical method has emerged as one of the most efficient sensing techniques for the determination of NB. The sensing performance of the electrochemical techniques depends on the electro-catalytic properties and conductivity of the electrode materials. In the past few years, various electrode materials, such as conductive metal ions, semiconducting metal oxides, metal–organic frameworks, and two-dimensional (2D) materials, have been used as the electrode material for the construction of the NB sensor. Thus, it is worth summarizing previous studies on the design and synthesis of electrode materials for the construction of the NB sensor. In this mini-review article, we summarize the previous reports on the synthesis of various advanced electrode materials, such as platinum (Pt) nanoparticles (NPs), silver (Ag) NPs, carbon dots (CDs), graphene, graphitic carbon nitride (g-C3N4), zinc stannate (ZnSnO3), cerium oxide (CeO2), zinc oxide (ZnO), and so on. Furthermore, the impacts of different electrode materials are systematically discussed for the sensing of NB. The advantages of, limitations of, and future perspectives on the construction of NB sensors are discussed. The aim of the present mini-review article is to enhance the knowledge and overall literature, working towards the construction of NB sensors.

Excellent Catalytic Performances of Embedded CoFe2O4 and TiO2 Nanoparticles on the Surface of Silica Matrix Toward Reduction of Toxic Cr (VI), Dyes, and Nitroaromatic Compounds

ABSTRACTA novel TiO2/CoFe2O4/SiO2 magnetic nanocomposite was successfully synthesized using sol–gel and hydrothermal methods. This nanocomposite consists of highly dispersed CoFe2O4 and TiO2 nanoparticles on the surface of the SiO2 matrix. The synthesis process involved the utilization of activated carbon, which played a dual role as a support for depositing the CoFe2O4 and TiO2 nanoparticles and as a rigid pattern for producing the silica matrix that enmeshed the nanoparticles. To study the unique characteristics of the samples, a range of analytical techniques, such as FT‐IR, VSM, XRD, SEM, N2 adsorption–desorption analysis, BET and EDX were employed. We carried out a complete examination of the catalytic performance of the TiO2/CoFe2O4/SiO2 nanocomposite for the reduction of different substances, including methyl orange (MO), safranin O (SO), methylene blue (MB), rhodamine B (RhB), chromium (VI) ions, and nitroaromatic compounds such as 2‐nitrophenol (2‐NP), 4‐nitroaniline (4‐NA), 2‐nitroaniline (2‐NA), and 4‐nitrophenol (4‐NP). The findings of our study demonstrate the remarkable efficacy of the TiO2/CoFe2O4/SiO2 nanocomposite in efficiently reducing dyes, Cr (VI), and nitroaromatic compounds to their desired forms in environmentally friendly aqueous solutions. Notably, the nanocomposite stands out due to its simple synthesis process, effortless recyclability, and its convenient separation by a magnet.

A Pyridazine‐Based Cadmium(II) Organic Framework With pcu Topology as a Luminance Sensor to Nitrobenzene, Al(III), and Cu(II) Ion

ABSTRACTIn the field of water decontamination, the design of luminance sensor for sensitive detection of heavy metal ion toxic and nitroaromatic compounds are important and challenging. Herein, a new luminescent Cd(II) metal–organic framework (MOF), {[Cd2(H2O)3(4‐CPCA)2]·2H2O}n (SNUT‐27) (H2(4‐CPCA) = 1‐(4‐carboxyphenyl)‐4‐oxo‐1,4‐dihydropyridazine‐3‐carboxylic acid) was obtained by the reaction of flexible ligand H2(4‐CPCA) and Cd(II) ions, characterized by single crystal X‐ray diffraction, PXRD, FT‐IR, and TGA, the samples were further analyzed. The analysis of single crystal X‐ray diffraction showed that SNUT‐27 possesses a distinct three‐dimensional spatial arrangement and demonstrates impressive fluorescence properties. Particularly, SNUT‐27 showed a highly sensitive response to the nitro‐aromatic compounds nitrobenzene by fluorescence quenching, and in contrast, showed a fluorescence enhancement response to Al3+ and Cu2+. SNUT‐27 can be effortlessly recycled by simply rinsing with water post‐sensing experiments, showcasing its reusability. Additionally, potential detection mechanisms have been explored.

Catalytic membrane with in situ formed gold nanoparticles via catechol redox chemistry for continuous flow catalysis

This work focuses on the development of catalytic membrane with gold nanoparticles (Au NPs) as the active phase for a comparative assessment of continuous flow catalytic reduction of 4-nitrophenol (4-NP). However, Au NPs are prepared in a way that relies mainly on toxic reagents and immobilization on the membrane surface is still dominated by deposition, which poses a risk of leakage. We reported a green method to immobilize and reduce Au NPs on membrane surface in situ using polymer brushes containing catechol groups. Scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) observations showed that the Au3+ had been reduced to Au NPs and were uniformly distributed on the PAN-PDAu membrane surface without obvious agglomeration. Under the dynamic flow mode, the PAN-PDAu membrane showed strong catalytic activity and stability for the reduction of nitroaromatic compounds. A possible mechanism the catalytic reduction of 4-NP was explored via density functional theory analysis, electron paramagnetic resonance (EPR) and liquid chromatography-mass spectrometry (LC-MS), which verified that the catechol groups contributed to the catalytic reduction reaction of 4-NP. In addition, the PAN-PDAu membrane also had an excellent antibacterial performance. This study provides new insights for the green design of catalytic membrane for industrial applications.

Synthesis of rGO/CuBi2O4 nanocomposite as an effective photocatalyst in the reduction of nitroaromatic compounds to corresponding amines under visible light

AbstractBACKGROUNDChemical pollutants, such as nitroaromatic compounds, have been a significant challenge in recent decades of human societies as they contribute to environmental pollution and pose serious health risks due to their high toxicity. One promising and green method to address this issue is the photocatalytic reduction of nitroaromatic compounds to their corresponding amino aromatic compounds. In this study, an rGO/CuBi2O4 nanocomposite was synthesized using the hydrothermal method, involving the simultaneous reduction of graphene oxide and the coupling of CuBi2O4 nanoparticles in its layers. The resulting heterogeneous structure was characterized using various techniques including FTIR, Raman, XPS, XRD, FESEM, TEM, EDAX, UV–Vis DRS, BET, PL spectroscopy, and EIS. Subsequently, the photocatalytic efficiency of the nanocomposite in reducing nitroaromatic compounds to the corresponding aromatic amines under visible light was evaluated.RESULTSThe results indicated that graphene oxide was effectively reduced and coupled with CuBi2O4 nanoparticles in the reduced graphene oxide sheets. The rGO/CuBi2O4 heterogeneous nanocomposite successfully reduced nitroaromatic compounds to the corresponding aromatic amines under visible light. Hydrazine monohydrate was used to supply the necessary hydrogen for the reaction.CONCLUSIONThis study confirmed the high photocatalytic activity of the rGO/CuBi2O4 heterogeneous nanocomposite. Our nanocomposite was more effective than others, reported in similar studies, at reducing nitroaromatic compounds to the corresponding amino aromatic compounds. Additionally, it demonstrated high recycling and reuse properties, as there was no significant change in reaction conversion percentage and nanocomposite amount after 16 reuses. © 2024 Society of Chemical Industry (SCI).

A novel procedure for selection of molecular descriptors: QSAR model for mutagenicity of nitroaromatic compounds.

Nitroaromatic compounds (NACs) stand out as pervasive organic pollutants, prompting an imperative need to investigate their hazardous effects. Computational chemistry methods play a crucial role in this exploration, offering a safer and more time-efficient approach, mandated by various legislations. In this study, our focus lay on the development of transparent, interpretable, reproducible, and publicly available methodologies aimed at deriving quantitative structure-activity relationship models and testing them by modelling the mutagenicity of NACs against the Salmonella typhimurium TA100 strain. Descriptors were selected from Mordred and RDKit molecular descriptors, along with several quantum chemistry descriptors. For that purpose, the genetic algorithm (GA), as the most widely used method in the literature, and three alternative algorithms (Boruta, Featurewiz, and ForwardSelector) combined with the forward stepwise selection technique were used. The construction of models utilized the multiple linear regression method, with subsequent scrutiny of fitting and predictive performance, reliability, and robustness through various statistical validation criteria. The models were ranked by the Multi-Criteria Decision Making procedure. Findings have revealed that the proposed methodology for descriptor selection outperforms GA, with Featurewiz showing a slight advantage over Boruta and ForwardSelector. These constructed models can serve as valuable tools for the quick and reliable prediction of NACs mutagenicity.

Free Radical Production Induced by Nitroimidazole Compounds Lead to Cell Death in Leishmania infantum Amastigotes.

Leishmania infantum is the vector-borne trypanosomatid parasite causing visceral leishmaniasis in the Mediterranean basin. This neglected tropical disease is treated with a limited number of obsolete drugs that are not exempt from adverse effects and whose overuse has promoted the emergence of resistant pathogens. In the search for novel antitrypanosomatid molecules that help overcome these drawbacks, drug repurposing has emerged as a good strategy. Nitroaromatic compounds have been found in drug discovery campaigns as promising antileishmanial molecules. Fexinidazole (recently introduced for the treatment of stages 1 and 2 of African trypanosomiasis), and pretomanid, which share the nitroimidazole nitroaromatic structure, have provided antileishmanial activity in different studies. In this work, we have tested the in vitro efficacy of these two nitroimidazoles to validate our 384-well high-throughput screening (HTS) platform consisting of L. infantum parasites emitting the near-infrared fluorescent protein (iRFP) as a biomarker of cell viability. These molecules showed good efficacy in both axenic and intramacrophage amastigotes and were poorly cytotoxic in RAW 264.7 and HepG2 cultures. Fexinidazole and pretomanid induced the production of ROS in axenic amastigotes but were not able to inhibit trypanothione reductase (TryR), thus suggesting that these compounds may target thiol metabolism through a different mechanism of action.

An Electrochemical Sensor Based on 3D Graphene‐Cyclodextrin Nanohybrid for Enhanced Sensitivity Detection of Nitroaromatic Compounds

This study presents an electrochemical sensor for sensitive detection of nitroaromatic compounds using a three‐dimensional (3D) porous graphene with polyoxypropylene supported reduced graphene oxide (PEA‐RGO) and embedded β‐cyclodextrins (β‐CD). First, PEA‐RGO was synthesized by the condensation reaction between graphene oxide (GO) and amino‐terminated polyoxypropylene (PEA), followed by hydrazine hydrate reduction. Then, β‐CD was embedded into the porous of the above 3D graphene to obtain PEA‐RGO/β‐CD nanohybrid. Various characterization techniques, such as microscopy imaging, infrared spectrometry, thermal analysis and electrochemical measurements, were employed to confirm the successful synthesis and unique 3D architecture structure of PEA‐RGO/β‐CD. Afterwards

Electrochemical treatment of simulated wastewater containing nitroaromatic compound with cobalt–titanium electrode

The Co3O4–Ti electrodes were successfully prepared via calcination method to degrade nitrogen-containing (TNP) simulate wastewater in this reaserch. SEM and EDS were employed to analyze the morphology and element composition on Co3O4–Ti electrode, revealing the successful load of cobalt element. Then the electrochemical performance was evaluated by CV and indicated a better redox performance of electrode. Furthermore, five factors as processing time (A), electrolyte concentration (B), pH (C), initial concentration of TNP (D), and current density (E) were systematic studied in electrical treatment process. The removal rate of TN could be 77%. After the optimization work by RSM, the removal rate of TN raised up to 81% with the condition as: A of 180 min, B of 0.05 M, C of 3, D of 400 mg L−1, and E of 20 mA cm−2. The sequence of significants is: C > D > A > E > B. Mechanism analysis revealed that the entire process could be divided into two stages. In the first stage, organic nitrogen compounds were converted into inorganic nitrogen species, such as NO3–N. The oxidation and reduction would react owing to the generating of ·OH at second stage in order to turn the NO3–N into NO2–N, NH4–N or N2. The activation of ·OH on the surface of Co3O4–Ti electrode possesses the exothermic nature with transition theory. The energy calculation of 1.168 eV indicated these reactions could occur spontaneously.