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1.
J Environ Manage ; 359: 121034, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38703649

RESUMEN

Frequent algal blooms cause algal cells and their algal organic matter (AOM) to become critical precursors of disinfection by-products (DBPs) during water treatment. The presence of bromide ion (Br-) in water has been demonstrated to affect the formation laws and species distribution of DBPs. However, few researchers have addressed the formation and toxicity alteration of halonitromethanes (HNMs) from algae during disinfection in the presence of Br-. Therefore, in this work, Chlorella vulgaris was selected as a representative algal precursor to investigate the formation and toxicity alteration of HNMs during UV/chloramination involving Br-. The results showed that the formation concentration of HNMs increased and then decreased during UV/chloramination. The intracellular organic matter of Chlorella vulgaris was more susceptible to form HNMs than the extracellular organic matter. When the Br-: Cl2 mass ratio was raised from 0.004 to 0.08, the peak of HNMs total concentration increased 33.99%, and the cytotoxicity index and genotoxicity index of HNMs increased 67.94% and 22.80%. Besides, the formation concentration and toxicity of HNMs increased with increasing Chlorella vulgaris concentration but decreased with increasing solution pH. Possible formation pathways of HNMs from Chlorella vulgaris during UV/chloramination involving Br- were proposed based on the alteration of nitrogen species and fluorescence spectrum analysis. Furthermore, the formation laws of HNMs from Chlorella vulgaris in real water samples were similar to those in deionized water samples. This study contributes to a better comprehension of HNMs formation from Chlorella vulgaris and provides valuable information for water managers to reduce hazards associated with the formation of HNMs.


Asunto(s)
Bromuros , Chlorella vulgaris , Chlorella vulgaris/efectos de los fármacos , Bromuros/química , Bromuros/toxicidad , Desinfección , Purificación del Agua , Rayos Ultravioleta
2.
Carbohydr Res ; 538: 109102, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38569333

RESUMEN

The classical Koenigs-Knorr glycosidation of bromides or chlorides promoted with Ag2O or Ag2CO3 works only with reactive substrates (ideally both donor and acceptor). This reaction was found to be practically ineffective with unreactive donors such as per-O-benzoylated mannosyl bromide. Recently, it was discovered that the addition of catalytic (Lewis) acids to a silver salt-promoted reaction has a dramatic effect on the reaction rate and yield. A tentative mechanism for this cooperatively-catalyzed glycosylation reaction has been proposed, and the improved understanding of the reaction led to more efficient protocols and broader applications to a variety of glycosidic linkages. Since Ag2O-mediated activation was introduced by German chemists Koenigs and Knorr, and "cooperatively catalyzed" is Kooperativ Katalysiert in German, we refer to this new reaction as "the 4K reaction."


Asunto(s)
Glicósidos , Ácidos de Lewis , Glicosilación , Catálisis , Bromuros
3.
Chemosphere ; 357: 142039, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38621488

RESUMEN

The coexistence of free chlorine and bromide under sunlight irradiation (sunlight/FC with Br-) is unavoidable in outdoor seawater swimming pools, and the formation of brominated disinfection byproducts could act more harmful than chlorinated disinfection byproducts. In this study, benzotriazole was selected as a model compound to investigate the degradation rate and the subsequent formation of disinfection byproducts via sunlight/FC with Br- process. The rate constants for the degradation of benzotriazole under pseudo first order conditions in sunlight/FC with Br- and sunlight/FC are 2.3 ± 0.07 × 10-1 min-1 and 6.0 ± 0.7 × 10-2 min-1, respectively. The enhanced degradation of benzotriazole can be ascribed to the generation of HO•, bromine species, and reactive halogen species (RHS) during sunlight/FC with Br-. Despite the fact that sunlight/FC with Br- process enhanced benzotriazole degradation, the reaction results in increasing tribromomethane (TBM) formation. A high concentration (37.8 µg/L) of TBM was detected in the sunlight/FC with Br-, which was due to the reaction of RHS. The degradation of benzotriazole was notably influenced by the pH value (pH 4 - 11), the concentration of bromide (0 - 2 mM), and free chlorine (1 - 6 mg/L). Furthermore, the concentration of TBM increased when the free chlorine concentrations increased, implying the formation potential of harmful TBM in chlorinated seawater swimming pools.


Asunto(s)
Bromuros , Cloro , Luz Solar , Triazoles , Contaminantes Químicos del Agua , Triazoles/química , Bromuros/química , Contaminantes Químicos del Agua/química , Contaminantes Químicos del Agua/análisis , Cloro/química , Desinfección , Trihalometanos/química , Agua de Mar/química , Desinfectantes/química , Desinfectantes/análisis
4.
J Phys Chem B ; 128(13): 3081-3089, 2024 Apr 04.
Artículo en Inglés | MEDLINE | ID: mdl-38506761

RESUMEN

Inorganic halide-based perovskites (e.g., cesium lead bromide) are tremendously useful semiconducting materials due to their unique optoelectronic properties. However, degradation of these perovskites under humid conditions is one of the major drawbacks to prevent their wide applications. Herein, passivated cesium lead bromide nanoparticles are synthesized using p-thiocresol as a passivating ligand, and this stable version of perovskite is later applied successfully as a sensor probe towards cholesterol detection. The designed sensor can detect cholesterol with a lower detection limit of 0.24 ppm and a fast response time of 10 s. The mechanism of quenching PTC@CsPbBr3 upon the gradual addition of cholesterol is discussed. Further, the sensor is successfully applied in the detection of cholesterol in real samples (blood serum). This work presents PTC@CsPbBr3 as a novel sensing platform for detecting cholesterol well in biomedical applications.


Asunto(s)
Bromuros , Compuestos de Calcio , Cesio , Colesterol , Plomo , Óxidos , Titanio
5.
J Biol Chem ; 300(4): 107210, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38519030

RESUMEN

Flavin-dependent halogenases are central enzymes in the production of halogenated secondary metabolites in various organisms and they constitute highly promising biocatalysts for regioselective halogenation. The mechanism of these monooxygenases includes formation of hypohalous acid from a reaction of fully reduced flavin with oxygen and halide. The hypohalous acid then diffuses via a tunnel to the substrate-binding site for halogenation of tryptophan and other substrates. Oxidized flavin needs to be reduced for regeneration of the enzyme, which can be performed in vitro by a photoreduction with blue light. Here, we employed this photoreduction to study characteristic structural changes associated with the transition from oxidized to fully reduced flavin in PyrH from Streptomyces rugosporus as a model for tryptophan-5-halogenases. The effect of the presence of bromide and chloride or the absence of any halides on the UV-vis spectrum of the enzyme demonstrated a halide-dependent structure of the flavin-binding pocket. Light-induced FTIR difference spectroscopy was applied and the signals assigned by selective isotope labeling of the protein moiety. The identified structural changes in α-helix and ß-sheet elements were strongly dependent on the presence of bromide, chloride, the substrate tryptophan, and the product 5-chloro-tryptophan, respectively. We identified a clear allosteric coupling in solution at ambient conditions between cofactor-binding site and substrate-binding site that is active in both directions, despite their separation by a tunnel. We suggest that this coupling constitutes a fine-tuned mechanism for the promotion of the enzymatic reaction of flavin-dependent halogenases in dependence of halide and substrate availability.


Asunto(s)
Proteínas Bacterianas , Flavinas , Oxidorreductasas , Streptomyces , Oxidorreductasas/metabolismo , Oxidorreductasas/química , Flavinas/metabolismo , Flavinas/química , Proteínas Bacterianas/metabolismo , Proteínas Bacterianas/química , Proteínas Bacterianas/genética , Streptomyces/enzimología , Oxidación-Reducción , Espectroscopía Infrarroja por Transformada de Fourier/métodos , Halogenación , Bromuros/química , Bromuros/metabolismo , Triptófano/metabolismo , Triptófano/química , Sitios de Unión , Cloruros/metabolismo , Cloruros/química
6.
J Hazard Mater ; 469: 133875, 2024 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-38457970

RESUMEN

Selective relaxant binding agents (SRBA) have great potential in clinical surgeries for the precise reversal of neuromuscular blockades. Understanding the relationship between the structure-affinity-reversal effects of SRBA and neuromuscular blockade is crucial for the design of new SRBAs, which has rarely been explored. Seven anionic pillar[5]arenes (AP5As) with different aliphatic chains and anionic groups at both edges were designed. Their binding affinities to the neuromuscular blocking agent decamonium bromide (DMBr) were investigated using 1H NMR, isothermal titration calorimetry (ITC), and theoretical calculations. The results indicate that the capture of DMBr by AP5As is primarily driven by electrostatic interactions, ion-dipole interactions and C-H‧‧‧π interactions. The optimal size matching between the carboxylate AP5As and DMBr was ∼0.80. The binding affinity increased with an increase in the charge quantity of AP5As. Further animal experiments indicated that the reversal efficiency increased with increasing binding affinity for carboxylate or phosphonate AP5As. However, phosphonate AP5As exhibited lower reversal efficiencies than carboxylate AP5As, despite having stronger affinities with DMBr. By understanding the structure-affinity-reversal relationships, this study provides valuable insights into the design of innovative SRBAs for reversing neuromuscular blockade.


Asunto(s)
Bloqueantes Neuromusculares , Fármacos Neuromusculares no Despolarizantes , Organofosfonatos , gamma-Ciclodextrinas , Animales , gamma-Ciclodextrinas/farmacología , Sugammadex , Bloqueantes Neuromusculares/farmacología , Bromuros
7.
Redox Biol ; 71: 103102, 2024 May.
Artículo en Inglés | MEDLINE | ID: mdl-38430684

RESUMEN

Peroxidasin (PXDN) is a secreted heme peroxidase that catalyzes the oxidative crosslinking of collagen IV within the extracellular matrix (ECM) via intermediate hypobromous acid (HOBr) synthesis from hydrogen peroxide and bromide, but recent findings have also suggested alternative ECM protein modifications by PXDN, including incorporation of bromide into tyrosine residues. In this work, we sought to identify the major target proteins for tyrosine bromination by HOBr or by PXDN-mediated oxidation in ECM from mouse teratocarcinoma PFHR9 cells. We detected 61 bromotyrosine (BrY)-containing peptides representing 23 proteins in HOBr-modified ECM from PFHR9 cells, among which laminins displayed the most prominent bromotyrosine incorporation. Moreover, we also found that laminin α1, laminin ß1, and tubulointerstitial nephritis antigen-like (TINAGL1) contained BrY in untreated PFHR9 cells, which depended on PXDN. We extended these analyses to lung tissues from both healthy mice and mice with experimental lung fibrosis, and in lung tissues obtained from human subjects. Analysis of ECM-enriched mouse lung tissue extracts showed that 83 ECM proteins were elevated in bleomycin-induced fibrosis, which included various collagens and laminins, and PXDN. Similarly, mRNA and protein expression of PXDN and laminin α/ß1 were enhanced in fibrotic mouse lung tissues, and also in mouse bone-marrow-derived macrophages or human fibroblasts stimulated with transforming growth factor ß1, a profibrotic growth factor. We identified 11 BrY-containing ECM proteins, including collagen IV α2, collagen VI α1, TINAGL1, and various laminins, in both healthy and mouse fibrotic lung tissues, although the relative extent of tyrosine bromination of laminins was not significantly increased during fibrosis. Finally, we also identified 7 BrY-containing ECM proteins in human lung tissues, again including collagen IV α2, collagen VI α1, and TINAGL1. Altogether, this work demonstrates the presence of several bromotyrosine-modified ECM proteins, likely involving PXDN, even in normal lung tissues, suggesting a potential biological function for these modifications.


Asunto(s)
Bromatos , Proteínas de la Matriz Extracelular , Fibrosis Pulmonar , Humanos , Animales , Ratones , Proteínas de la Matriz Extracelular/genética , Proteínas de la Matriz Extracelular/metabolismo , Bromuros/efectos adversos , Bromuros/metabolismo , Laminina/genética , Laminina/metabolismo , Matriz Extracelular/metabolismo , Pulmón/metabolismo , Peroxidasina , Colágeno Tipo IV/metabolismo , Fibrosis Pulmonar/inducido químicamente , Fibrosis Pulmonar/genética , Fibrosis Pulmonar/metabolismo , Tirosina/metabolismo
8.
Indian J Pharmacol ; 56(1): 28-36, 2024 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-38454586

RESUMEN

OBJECTIVES: During the past few decades, various compounds have been researched for their potential as radioprotectants, and many of them were found to be safe and effective in several preclinical models. However, many of these compounds were found to have serious adverse effects when evaluated in clinical settings, thereby making them unsuitable for human applications. 5-hydroxytryptophan (5-HTP) and S-(2-aminoethyl) isothiouronium bromide hydrobromide (AET) act in a synergistic fashion to promote radioprotection. The present study primarily emphasizes the safety of fixed dose of 5-HTP + AET in the lungs of C57BL/6 mice, a well-known model used in drug safety studies. MATERIALS AND METHODS: Post-administration of the combination of HTP+AET at specific time points, blood and bronchoalveolar lavage fluid (BALF) were collected for the analysis of inflammatory and oxidative stress markers of the lungs. Thereafter, the mice were sacrificed and the lungs were dissected out, weighed, and fixed in formalin for histopathological studies. RESULTS: The inflammatory biomarkers: tumor necrosis factor-alpha and interleukin-10 and oxidative stress biomarkers: 8-isoprostane and 8-hydroxy-2'-deoxyguanosine were found to have normal levels in blood and BALF in both control and treatment groups, which was further supported by normal histological findings. In addition, other endpoints such as food and water intake were found to be within normal limits. CONCLUSION: The present safety study reflects that the combination has no adverse effects on the lungs of the experimental mouse. Further, evaluation in higher mammals including nonhuman primates is essential prior to validation of the safety of the combination in humans.


Asunto(s)
Protectores contra Radiación , Humanos , Ratones , Animales , beta-Aminoetil Isotiourea , 5-Hidroxitriptófano , Bromuros/toxicidad , Isotiuronio , Roedores , Ratones Endogámicos C57BL , Pulmón , Biomarcadores , Líquido del Lavado Bronquioalveolar
9.
Medicine (Baltimore) ; 103(10): e37309, 2024 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-38457591

RESUMEN

To explore the effect of probiotics combined with budesonide and ipratropium bromide in the treatment of chronic obstructive pulmonary disease (COPD) on lung function and gut microbiota. This was a retrospective study of prospectively collected clinical data of 118 patients with COPD admitted to our hospital between January 2020 and December 2022. According to the treatment records, 59 patients received budesonide and irpratropium bromide (control group), and 59 patients received probiotics combined with budesonide and irpratropium bromide (observation group). The lung function, inflammatory factor levels, airway remodeling, and gut microbiota before and after treatment were compared between the 2 groups. After treatment, FVC, MMEF, PEF, and FEV1 in the 2 groups were higher than before treatment, and the values in the observation group were higher than those in the control group (P < .05). After treatment, the serum levels of TNF-α, IL-6, and PCT in the 2 groups were lower than before treatment, and the levels in the observation group were lower than those in the control group (P < .05). After treatment, the levels of serum MMP-9, VEGF, basic fibroblast growth factor, and NGF in the 2 groups were lower than before treatment, and the levels in the observation group were lower than those in the control group (P < .05). After treatment, the levels of lactobacilli and bifidobacteria in the 2 groups increased compared to those before treatment, and the observation group had a higher level, while the levels of Enterobacteriaceae and Enterococcus were lower in the observation group than those before treatment (P < .05). Based on budesonide and irpratropium bromide, probiotic treatment of COPD is more conducive to reducing the degree of inflammatory reactions, inhibiting airway remodeling, regulating the level of gut microbiota, and promoting the recovery of lung function.


Asunto(s)
Budesonida , Enfermedad Pulmonar Obstructiva Crónica , Humanos , Budesonida/uso terapéutico , Ipratropio/uso terapéutico , Estudios Retrospectivos , Remodelación de las Vías Aéreas (Respiratorias) , Bromuros/uso terapéutico , Enfermedad Pulmonar Obstructiva Crónica/tratamiento farmacológico , Broncodilatadores/uso terapéutico
10.
Luminescence ; 39(3): e4706, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38483095

RESUMEN

Inorganic cesium lead halide perovskites have evoked wide popularity because of their excellent optoelectronic properties, high photoluminescence (PL) quantum yield (PLQY), and narrowband emission. Here, cesium lead bromide (CsPbBr3 ) quantum dots (QDs) were synthesized via the ligand-assisted re-precipitation method. Post-synthesis treatment of CsPbBr3 QDs using antimony tribromide improved the PL stability and optoelectronic properties of the QDs. In addition, the PLQY of the post-treated sample was enhanced to 91% via post-treatment, and the luminescence observed was maintained for 8 days. The post-synthesis treatment ensured defect passivation and improved the stability of CsPbBr3 perovskite QDs. High-resolution transmission electron microscopy revealed the presence of more ordered, uniform-sized CsPbBr3 QDs after post-synthesis treatment, and the uniformity of the sample improved as the day passed. The formation of a mixed crystal phase was observed from X-ray diffraction in both as-synthesized, as well as post-treated QDs samples with the possibility of a polycrystalline nature in the post-treated CsPbBr3 QDs as per the selected area electron diffraction pattern. The X-ray photoelectron spectroscopy spectra confirmed the presence of antimony and the possibility of defect passivation in the post-treated samples. These QDs can act as potential candidates in various optoelectronic applications such as photodetectors and light-emitting diodes due to their high PLQY and longer lifetime.


Asunto(s)
Antimonio , Bromuros , Compuestos de Calcio , Óxidos , Puntos Cuánticos , Titanio , Cesio
11.
Anal Chem ; 96(12): 4884-4890, 2024 Mar 26.
Artículo en Inglés | MEDLINE | ID: mdl-38494753

RESUMEN

The parallel double-stranded DNA (dsDNA) demonstrates potential utility in molecular biology, diagnosis, therapy, and molecular assembly. However, techniques for the characterization of parallel dsDNA are limited. Here, we demonstrate that a series of intensive characteristic Raman bands of three parallel dsDNAs, which are stabilized by reverse Hoogsteen A+·A+ base pairs or hemiprotonated C+·C, G·G minor groove edge, Hoogsteen A·A base pairs, or Hoogsteen T·A, C+·G base pairs, have been observed by surface-enhanced Raman spectroscopy (SERS) when the gold nanoparticles modified by bromine and magnesium ions (Au BMNPs) were used as substrates. The featured bands can not only accurately discriminate parallel dsDNA from antiparallel one but also identify the strand orientation within dsDNA. The proposed approach will have a significant impact on DNA analysis, especially in the detection and differentiation of various DNA conformations.


Asunto(s)
Oro , Nanopartículas del Metal , Oro/química , Espectrometría Raman , Bromuros , Nanopartículas del Metal/química , ADN/química
12.
Front Biosci (Landmark Ed) ; 29(3): 125, 2024 Mar 22.
Artículo en Inglés | MEDLINE | ID: mdl-38538265

RESUMEN

BACKGROUND: The prevalence of laryngeal squamous cell carcinoma (LSCC) is increasing, and it poses a significant threat to human health; therefore, identifying specific targets for LSCC remains crucial. METHODS: Bioinformatics analysis was used to compare the different expression genes expressed in LSCC. Immunohistochemical assay and western blotting were used to analysis protein expression. Cell viability was measured by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide)((4,5 Dimethyl thiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide)4,5 Dimethyl thiazol-2-Yl)-2,5-Diphenyltetrazolium Bromide (MTT) and 5-ethynyl 2'-deoxyuridine (Edu) assay. Flow cytometry was used to measure the cell cycle. Cell migration was measured by wound healing assay and transwell assay. RESULTS: Our analysis revealed 36 upregulated and 65 downregulated differentially expressed genes (DEGs) when comparing LSCC tumors to adjacent tissues, with cornulin (CRNN) identified as a key hub gene connecting these DEGs. We observed a consistent downregulation of CRNN expression in LSCC cell lines and tissues and was associated with poor patient survival and the tumor microenvironment. CRNN overexpression was found to significantly inhibit cell growth, cell cycle progression, migration and invasion, while CRNN knockdown had the opposite effects. Additionally, in vivo experiments demonstrated that CRNN overexpression suppressed tumor growth in nude mice. CONCLUSIONS: CRNN functions as a potential tumor suppressor and regulates important aspects of LSCC, providing valuable insights into the role of CRNN in LSCC pathogenesis and potential for targeted therapeutic interventions.


Asunto(s)
Carcinoma de Células Escamosas , Neoplasias Laríngeas , MicroARNs , Carcinoma de Células Escamosas de Cabeza y Cuello , Animales , Humanos , Ratones , Bromuros/metabolismo , Carcinoma de Células Escamosas/metabolismo , Línea Celular Tumoral , Proliferación Celular/genética , Regulación Neoplásica de la Expresión Génica , Neoplasias Laríngeas/genética , Neoplasias Laríngeas/metabolismo , Neoplasias Laríngeas/patología , Ratones Desnudos , MicroARNs/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/genética , Carcinoma de Células Escamosas de Cabeza y Cuello/metabolismo , Carcinoma de Células Escamosas de Cabeza y Cuello/patología , Microambiente Tumoral
13.
J Nanobiotechnology ; 22(1): 123, 2024 Mar 20.
Artículo en Inglés | MEDLINE | ID: mdl-38504272

RESUMEN

BACKGROUND: Photodynamic therapy (PDT) efficacy of bismuth sulfide (Bi2S3) semiconductor has been severely restricted by its electron-hole pairs (e--h+) separation inefficiency and oxygen (O2) deficiency in tumors, which greatly hinders reactive oxygen species (ROS) generation and further clinical application of Bi2S3 nanoparticles (NPs) in biomedicine. RESULTS: Herein, novel Bi2S3/titanium carbide (Ti3C2) two-dimensional nano-heterostructures (NHs) are designed to realize multimode PDT of synchronous O2 self-supply and ROS generation combined with highly efficient photothermal tumor elimination for hypoxic tumor therapy. Bi2S3/Ti3C2 NHs were synthesized via the in situ synthesis method starting from Ti3C2 nanosheets (NSs), a classical type of MXene nanostructure. Compared to simple Bi2S3 NPs, Bi2S3/Ti3C2 NHs significantly extend the absorption to the near-infrared (NIR) region and enhance the photocatalytic activity owing to the improved photogenerated carrier separation, where the hole on the valence band (VB) of Bi2S3 can react with water to supply O2 for the electron on the Ti3C2 NSs to generate ·O2- and ·OH through electron transfer. Furthermore, they also achieve 1O2 generation through energy transfer due to O2 self-supply. After the modification of triphenylphosphium bromide (TPP) on Bi2S3/Ti3C2 NHs, systematic in vitro and in vivo evaluations were conducted, revealing that the synergistic-therapeutic outcome of this nanoplatform enables complete eradication of the U251 tumors without recurrence by NIR laser irradiation, and it can be used for computed tomography (CT) imaging because of the strong X-ray attenuation ability. CONCLUSION: This work expands the phototherapeutic effect of Bi2S3-based nanoplatforms, providing a new strategy for hypoxic tumor theranostics.


Asunto(s)
Neoplasias , Fotoquimioterapia , Humanos , Fotoquimioterapia/métodos , Bromuros/uso terapéutico , Terapia Fototérmica , Especies Reactivas de Oxígeno , Titanio/farmacología , Neoplasias/tratamiento farmacológico , Oxígeno , Hipoxia/tratamiento farmacológico , Rayos Infrarrojos , Línea Celular Tumoral
14.
Chembiochem ; 25(7): e202300848, 2024 Apr 02.
Artículo en Inglés | MEDLINE | ID: mdl-38353515

RESUMEN

We have recently discovered that ester-stabilized phosphorus ylides, resulting from deprotonation of a phosphonium salt such as [Ph3PCH2COOR], can transfer protons across artificial and biological membranes. To create more effective cationic protonophores, we synthesized similar phosphonium salts with one ((heptyloxycarbonylmethyl)(p-tolyl)bromide) or two ((butyloxycarbonylmethyl)(3,5-xylyl)osphonium bromide) methyl substituents in the phenyl groups. The methylation enormously augmented both protonophoric activity of the ylides on planar bilayer lipid membrane (BLM) and uncoupling of mammalian mitochondria, which correlated with strongly accelerated flip-flop of their cationic precursors across the BLM.


Asunto(s)
Mitocondrias Hepáticas , Fósforo , Animales , Mitocondrias Hepáticas/metabolismo , Fósforo/metabolismo , Ésteres/metabolismo , Bromuros/metabolismo , Metilación , Membrana Dobles de Lípidos/metabolismo , Mamíferos
15.
Environ Sci Pollut Res Int ; 31(11): 17156-17163, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-38334926

RESUMEN

Phosphonates have received a widespread attention in wastewater treatment due to their potential threat to the water environment. Advanced oxidation processes (AOPs) are feasible methods to degrade phosphonates, and most of the coexisting substances in water show a negative factor during their oxidation. However, the effect of bromide (Br-) on the degradation of phosphonates in peroxymonosulfate (PMS) activation is still unclear. Herein, using 1-hydroxyethane 1,1-diphosphonic acid (HEDP) as a target phosphonate, Br- could remarkably enhance the degradation of HEDP in PMS activation compared to the PMS alone. Under the condition of pH = 7.0, the optimal degradation efficiency of HEDP is 84.8% in the PMS/Br- process after 30-min reaction, whereas no significant oxidation is obtained in the PMS/I- and PMS/Cl- processes. Multiple experiments (i.e., electron paramagnetic resonance (EPR), radical quenching experiments and chemical probs) confirm that free bromine, SO4•- and HO• paly a minor role in HEDP removal, and bromine radical species make a dominant responsible for HEDP oxidation. Additionally, NO3-, SO42-, Cl-, and HCO3- have a little effect on the degradation of HEDP, but the HEDP removal is greatly inhibited in the presence of humic acid (HA). However, the degradation efficiency of HEDP using PMS/Br- process in river and sewage is a much higher than UV/persulfate (PDS) and UV/H2O2 processes. This study provides a new sight into the effect of Br- on the degradation phosphonates in PMS activation process.


Asunto(s)
Organofosfonatos , Contaminantes Químicos del Agua , Peróxido de Hidrógeno/química , Bromuros , Bromo , Ácido Etidrónico , Contaminantes Químicos del Agua/análisis , Peróxidos/química , Oxidación-Reducción , Agua
16.
Environ Pollut ; 346: 123645, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38402939

RESUMEN

Brominated flame retardants (BFRs) are bromine-bearing additives added to the polymeric fraction in various applications to impede fire ignition. The Stockholm Convention and various other legislations abolished legacy BFRs usage and hence, the so-called novel BFRs (NBFRs) were introduced into the market. Recent studies spotlighted their existence in household dust, aquifers and aquatic/aerial species. Co-pyrolysis of BFRs with metal oxides has emerged as a potent chemical recycling approach that produces a bromine-free stream of hydrocarbon. Herein, we investigate the debromination of two prominent two NBFRs; namely tetrabromobisphenol A 2,3-dibromopropyl ether (TD) and tetrabromobisphenol A diallyl ether (TAE) through their co-pyrolysis with zinc oxide (ZnO) and franklinite (ZnFe2O4). Most of the zinc content in electrical arc furnace dust (EAFD) exists in the form of these two metal oxides. Conversion of these metal oxides into their respective bromides could also assist in the selective extraction of the valuable zinc content in EAFD. The debromination potential of both oxides was unveiled via a multitude of characterization studies to analyze products (char, gas and condensates). The thermogravimetric analysis suggested a pyrolytic run up to 500 °C and the TAE treatment with ZnO produced only a trivial amount of brominated compounds (relative area, 0.83%). Phenol was the sole common compound in condensable products; potentially formed by the ß-scission debromination reaction from the parental molecular skeleton. Inorganic compounds and methane were the major constituents in the gaseous products. The pyrochar analyses confirmed the presence of metal bromides retained in the residue, averting the bromine release into the atmosphere. The ion chromatography analysis portrayed <8% of HBr gas release into the atmosphere upon pyrolysis with ZnO. The ZnO dominance herein envisaged further probes into other spinel ferrites in combating brominated polymers.


Asunto(s)
Residuos Electrónicos , Retardadores de Llama , Hidrocarburos Bromados , Bifenilos Polibrominados , Óxido de Zinc , Retardadores de Llama/análisis , Residuos Electrónicos/análisis , Bromo , Bromuros , Reciclaje/métodos , Polímeros , Zinc/análisis , Polvo , Éteres , Hidrocarburos Bromados/análisis
17.
Water Res ; 253: 121148, 2024 Apr 01.
Artículo en Inglés | MEDLINE | ID: mdl-38387263

RESUMEN

This publication summarizes my journey in the field of chemical oxidation processes for water treatment over the last 30+ years. Initially, the efficiency of the application of chemical oxidants for micropollutant abatement was assessed by the abatement of the target compounds only. This is controlled by reaction kinetics and therefore, second-order rate constant for these reactions are the pre-requisite to assess the efficiency and feasibility of such processes. Due to the tremendous efforts in this area, we currently have a good experimental data base for second-order rate constants for many chemical oxidants, including radicals. Based on this, predictions can be made for compounds without experimental data with Quantitative Structure Activity Relationships with Hammet/Taft constants or energies of highest occupied molecular orbitals from quantum chemical computations. Chemical oxidation in water treatment has to be economically feasible and therefore, the extent of transformation of micropollutants is often limited and mineralization of target compounds cannot be achieved under realistic conditions. The formation of transformation products from the reactions of the target compounds with chemical oxidants is inherent to oxidation processes and the following questions have evolved over the years: Are the formed transformation products biologically less active than the target compounds? Is there a new toxicity associated with transformation products? Are transformation products more biodegradable than the corresponding target compounds? In addition to the positive effects on water quality related to abatement of micropollutants, chemical oxidants react mainly with water matrix components such as the dissolved organic matter (DOM), bromide and iodide. As a matter of fact, the fraction of oxidants consumed by the DOM is typically > 99%, which makes such processes inherently inefficient. The consequences are loss of oxidation capacity and the formation of organic and inorganic disinfection byproducts also involving bromide and iodide, which can be oxidized to reactive bromine and iodine with their ensuing reactions with DOM. Overall, it has turned out in the last three decades, that chemical oxidation processes are complex to understand and to manage. However, the tremendous research efforts have led to a good understanding of the underlying processes and allow a widespread and optimized application of such processes in water treatment practice such as drinking water, municipal and industrial wastewater and water reuse systems.


Asunto(s)
Contaminantes Químicos del Agua , Purificación del Agua , Bromuros , Yoduros , Contaminantes Químicos del Agua/química , Oxidación-Reducción , Oxidantes/química
18.
Int J Mol Sci ; 25(2)2024 Jan 10.
Artículo en Inglés | MEDLINE | ID: mdl-38255957

RESUMEN

In this work, we present the effect of graphene nanoplatelets (GnPs) modification with ionic liquids (ILs). The textural properties of graphene nanoplatelets (GnPs) used as styrene-butadiene rubber's filler and the thermal properties of the composites obtained with the use of the mentioned fillers were investigated. GnPs were modified with 1-butylpyridinium bromide (BPyBr) and 4-methyl-1-butylpyridinium bromide (BmPyBr) through two different ways. One strategy has been to deposit the filler modifier from the solution. The second one involved the modification of the filler with ionic liquids in bulk during the preparation of elastomer blends. Settlement of the proposed ionic liquids onto the GnPs' surface led to significant changes in the textural characteristics. BPyBr has restricted the filler's microporosity, whereas BmPyBr has caused the formation of a more opened filler structure without the increase in its average pore size. GnPs modified with ILs led to reducing the temperature of vulcanization of SBR compounds and affected the thermal stability of the composites.


Asunto(s)
Grafito , Hidrocarburos Bromados , Líquidos Iónicos , Bromuros , Elastómeros , Excipientes
19.
Carbohydr Res ; 536: 109033, 2024 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-38295530

RESUMEN

Glycosyl halides are historically one of the first glycosyl donors used in glycosylation reactions, and interest in glycosylation reactions involving this class of glycosyl donors is currently increasing. New methods for their activation have been proposed and effective syntheses of oligosaccharides with their participation have been developed. At the same time, the possibilities of using these approaches to the synthesis of sialosides are restricted by the limited diversity of known sialyl halides (previously, mainly sialyl chlorides, less often sialyl bromides and sialyl fluorides, with acetyl (Ac) groups at the oxygen atoms and AcNH, Ac2N and N3 groups at C-5 were used). This work describes the synthesis of six new N-acetyl- and N-trifluoroacetyl-sialyl chlorides and bromides with O-chloroacetyl and O-trifluoroacetyl protective groups. Preparation of N,O-trifluoroacetyl protected derivatives was made possible due to development of the synthesis of sialic acid methyl ester pentaol with N-trifluoroacetyl group.


Asunto(s)
Bromuros , Ácido N-Acetilneuramínico , Glicosilación , Oligosacáridos , Ésteres
20.
Environ Geochem Health ; 46(2): 54, 2024 Jan 22.
Artículo en Inglés | MEDLINE | ID: mdl-38252329

RESUMEN

Brominated halonitromethanes (Br-HNMs) are generated in water disinfection processes and present high toxicity to human health. This work used aspartic acid (ASP) as the precursor to reveal that bromide (Br-) induced the production of Br-HNMs in the UV/chlorine disinfection process. Consequently, six Br-HNMs were identified, and their yields presented an increasing and then declining evolution over the reaction time from 0 to 15 min. Also, the total Br-HNMs yield reached the maximum of 251.1 µg L-1 at 5 min and then declined to 107.1 µg L-1. The total Br-HNMs yield increased from 2.40 to 251.14 µg L-1 with the increase of Cl2:Br- ratios from 0.25 to 3.0 by increasing free chlorine dosage with a fixed Br- concentration, and it increased from 207.59 to 251.14 µg L-1 and then decreased to 93.44 µg L-1 with the increase of Cl2:Br- ratio from 1.0 to 3.6 by increasing Br- concentration with a fixed free chlorine dosage. Besides, the total Br-HNMs yield reached the highest value (251.14 µg L-1) at pH 7.0 and the lowest value (74.20 µg L-1) at pH 8.0. Subsequently, the possible reaction mechanism of Br-HNMs generated from ASP was deduced, and the changes in toxicity of Br-HNMs also followed an increasing and then declining trend, closely relating to Br-HNMs yields and Br- utilization. This work explored and illustrated the yields, influence factors, reaction mechanisms, and toxicity of Br-HNMs formed from Br- containing ASP water during UV/chlorine disinfection, which might help to control Br-HNMs formation.


Asunto(s)
Ácido Aspártico , Cloro , Humanos , Bromuros , Desinfección , Cloruros , Agua
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