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1.
Acta Crystallogr C Struct Chem ; 78(Pt 8): 437-448, 2022 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-35924362

RESUMO

Creatinine, a biologically important compound, is used to analyze kidney function and kidney diseases in the human body. The salt form of creatinine is used in the formation of drug materials like anti-HIV, antifungal, antiprotozoal, antiviral and antitumour compounds. Here we report the solid-state structures of three new crystalline salts, namely, creatininium (2-amino-1-methyl-4-oxo-4,5-dihydro-1H-imidazol-3-ium) bromide, C4H8N3O+·Br-, (I), creatininium 3-aminobenzoate, C4H8N3O+·C7H6NO2-, (II), and creatininium 3,5-dinitrobenzoate, C4H8N3O+·C7H3N2O6-, (III). These salts have been synthesized and characterized by single-crystal X-ray diffraction and Hirshfeld surface analysis. The structural chemistry of salts (I)-(III) and their crystal packing are discussed in detail. The primary interaction between the creatinine cation and the acid anion in the three salts is N-H...Br/O hydrogen bonds. In salt (I), the creatinine cation and bromide anion are connected through a pair of N-H...Br hydrogen bonds forming R42(8) and R42(12) ring motifs. In salts (II) and (III), the creatinine cation interacts with the corresponding anion via a pair of N-H...O hydrogen bonds. The crystal structure is further stabilized by C-H...O and O-H...O hydrogen bonds with the ring motifs R22(8), R21(7) and R21(6). Furthermore, the crystal structures are stabilized by π-π, C-H...π, C-O...π and N-O...π stacking interactions. The contributions made by each hydrogen bond in maintaining the crystal structure stability has been quantified by Hirshfeld surface analysis.


Assuntos
Ácido Bromídrico , Sais , Brometos , Creatinina , Cristalografia por Raios X , Humanos , Ligação de Hidrogênio , Estrutura Molecular , Nitrobenzoatos , Sais/química , meta-Aminobenzoatos
2.
Redox Biol ; 54: 102385, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35803124

RESUMO

Peroxidasin (PXDN) is involved in the crosslinking of collagen IV, a major constituent of basement membranes. Disruption of basement membrane integrity as observed in genetic alterations of collagen IV or PXDN can result in developmental defects and diverse pathologies. Hence, the study of PXDN activity in (patho)physiological contexts is highly relevant. So far, measurements of PXDN activity have been reported from purified proteins, cell lysates and de-cellularized extracellular matrix. Here, for the first time we report the measurement of PXDN activity in live cells using the Amplex Red assay with a signal amplifying modification. We observe that bromide addition enhances the obtained signal, most likely due to formation of HOBr. Abrogation of signal amplification by the HOBr scavenger carnosine supports this hypothesis. Both, pharmacological inhibition as well as complementary genetic approaches confirm that the obtained signal is indeed related to PXDN activity. We validate the modified assay by investigating the effect of Brefeldin A, to inhibit the secretory pathway and thus the access of PXDN to the extracellular Amplex Red dye. Our method opens up new possibilities to investigate the activity of PXDN in (patho)physiological contexts.


Assuntos
Brometos , Proteínas da Matriz Extracelular , Colágeno Tipo IV/metabolismo , Proteínas da Matriz Extracelular/genética , Proteínas da Matriz Extracelular/metabolismo , Peroxidase/metabolismo
3.
Chem Commun (Camb) ; 58(59): 8202-8205, 2022 Jul 21.
Artigo em Inglês | MEDLINE | ID: mdl-35788778

RESUMO

Herein, nickel-catalyzed decarboxylative cross-coupling of indole-3-acetic acids with aryl bromides by convergent paired electrolysis was developed in an undivided cell. This protocol features good functional group tolerance, and is chemical redox agent- and sacrificial electrode-free. Mechanistic studies indicated that the base was crucial for the decarboxylation step and a NiI/NiIII catalytic cycle was involved in this transformation.


Assuntos
Brometos , Níquel , Acetatos , Catálise , Eletrólise , Indóis , Estrutura Molecular
4.
Org Lett ; 24(27): 4987-4991, 2022 07 15.
Artigo em Inglês | MEDLINE | ID: mdl-35776983

RESUMO

An enantio- and regioconvergent nickel-catalyzed benzylation of racemic silylated allylic electrophiles with benzylzinc nucleophiles is reported. The key feature of this method is that the homocoupling pathways of both the nucleophile and the electrophile are minimized. A diverse set of electronically modified benzylzinc reagents was tolerated. The vinylsilane products with allylic stereocenters were formed in moderate to high yields with high enantioselectivities. The regioconvergence is the result of the steering effect of the silyl group.


Assuntos
Brometos , Níquel , Catálise , Indicadores e Reagentes
5.
Molecules ; 27(14)2022 Jul 06.
Artigo em Inglês | MEDLINE | ID: mdl-35889205

RESUMO

In recent years, there has been increasing interest in daily-use chemical products providing a pleasant scent. The added fragrance molecules may induce microstructural transitions of surfactant aggregates, which further affect the physical and chemical properties of the products. Here, the effects of four types of aromatic alcohols (cinnamyl alcohol, phenyl ethanol, phenyl methanol and anisyl alcohol) on cetyltrimethylammonium bromide (CTAB)/KBr aggregates were studied. The combined results from rheology, dynamic light scattering, and transmission electron microscopy measurements showed that cinnamyl alcohol induced significant micellar growth, while increases in micellar growth were less obvious for the other aromatic alcohols. The changes in the interfacial molarities of water, aromatic alcohol, and bromide ions during such transitions were studied using the chemical trapping method. Transitions resulting from added cinnamyl alcohol were accompanied by significant declines in interfacial water and bromide ion molarities, and a rise in interfacial alcohol molarity. The marked decrease in interfacial water molarity was not observed in previous studies of the octanol induced formation of wormlike micelles and vesicles, indicating that a different mechanism was presented in the current system. Nuclear magnetic resonance investigation showed that π-π stacking between cinnamyl alcohols, but not cation-π interactions between alcohols and CTAB headgroups, facilitated the tight packing of alcohol molecules in CTAB aggregates and the repulsion of water from the interfacial region. The current study may provide a theoretical basis for the morphological regulation of surfactant aggregates in the presence of additives.


Assuntos
Surfactantes Pulmonares , Tensoativos , Brometos , Cetrimônio , Compostos de Cetrimônio/química , Excipientes , Micelas , Odorantes , Tensoativos/química , Água/química
6.
Org Lett ; 24(28): 5023-5028, 2022 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-35822901

RESUMO

We herein report a Ni-catalyzed three-component cross-electrophile coupling of 1,3-dienes with aldehydes and aryl bromides using manganese metal as the reducing agent. This efficient protocol accomplishes dicarbofunctionalization of 1,3-dienes to synthesize diverse structural 1,4-disubstituted homoallylic alcohols by forming two new C-C bonds in one time. Mechanistic study suggests that an allyl-nickel(I) species is involved in the catalytic cycle.


Assuntos
Aldeídos , Níquel , Aldeídos/química , Brometos , Catálise , Estrutura Molecular , Níquel/química , Polienos
7.
Org Lett ; 24(28): 5186-5191, 2022 07 22.
Artigo em Inglês | MEDLINE | ID: mdl-35833707

RESUMO

We herein report a simple protocol for metal-free cross-coupling between unactivated alkyl iodides and terminal alkynyl bromides promoted by visible light. The salient features of this transformation are the utilization of an organic photocatalyst and commercially available tri-n-butylamine as a reductant. This protocol couples a variety of unactivated iodoalkanes containing different functional groups and with a variety of terminal alkynyl bromides under mild reaction conditions to afford the substituted alkynes in good yields.


Assuntos
Alcinos , Brometos , Catálise , Iodetos , Luz
8.
J Org Chem ; 87(12): 8048-8058, 2022 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-35666844

RESUMO

A visible-light-promoted nickel/photoredox-catalyzed reductive cross-coupling reaction between vinyl bromides and benzyl chlorides is reported. A diverse array of enantioenriched allylic centers containing products could be achieved in good yields (up to 90%) and high enantioselectivities (up to 95% ee). The mechanistic studies show that this reductive cross-coupling involves a radical pathway.


Assuntos
Brometos , Níquel , Catálise , Cloretos , Estrutura Molecular , Estereoisomerismo
9.
Chem Asian J ; 17(15): e202200448, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-35661611

RESUMO

An efficient silver-promoted decarboxylative gem-difluoromethylenation of aryl- or alkyl-substituted α,ß-unsaturated carboxylic acids with readily available benzo-1,3-diazolic difluoromethyl bromides has been developed. This convenient transformation demonstrated good functional-group tolerability and broad substrate scope, and afforded the allylic difluorides in good to excellent yields with exclusive E-stereoselectivity under mild reaction conditions.


Assuntos
Ácidos Carboxílicos , Prata , Brometos , Catálise , Descarboxilação
10.
Nat Commun ; 13(1): 3337, 2022 06 09.
Artigo em Inglês | MEDLINE | ID: mdl-35680930

RESUMO

The wide-ranging potencies of bioactive N-fused heterocycles inspire the development of synthetic transformations that simplify preparation of their complex, diverse structural motifs. Heteroaryl ketones are ubiquitous, readily available, and inexpensive molecular scaffolds, and are thus synthetically appealing as precursors in preparing N-fused heterocycles via intramolecular acyl-transfer. To best of our knowledge, acyl-transfer of unstrained heteroaryl ketones remains to be demonstrated. Here, we show an acyl transfer-annulation to convert heteroaryl ketones to N-fused heterocycles. Driven via aromatisation, the acyl of a heteroaryl ketone can be transferred from the carbon to the nitrogen of the corresponding heterocycle. The reaction commences with the spiroannulation of a heteroaryl ketone and an alkyl bromide, with the resulting spirocyclic intermediate undergoing aromatisation-driven intramolecular acyl transfer. The reaction conditions are optimised, with the reaction exhibiting a broad substrate scope in terms of the ketone and alkyl bromide. The utility of this protocol is further demonstrated via application to complex natural products and drug derivatives to yield heavily functionalised N-fused heterocycles.


Assuntos
Brometos , Cetonas , Carbono/química , Cetonas/química , Nitrogênio/química
11.
Biochem Biophys Res Commun ; 618: 113-118, 2022 08 27.
Artigo em Inglês | MEDLINE | ID: mdl-35717905

RESUMO

Lipid giant vesicles represent a versatile minimal model system to study the physicochemical basis of lipid membrane fusion. Membrane fusion processes are also of interest in synthetic cell research, where cell-mimicking behavior often requires dynamically interacting compartments. For these applications, triggered fusion compatible with transcription-translation systems is key in achieving complexity. Recently, a photosensitive surfactant, azobenzene trimethylammonium bromide (AzoTAB), has been reported to induce membrane fusion by a photoinduced conformational change. Using imaging flow cytometer (IFC) and confocal microscopy we quantitatively investigated photoinduced AzoTAB-mediated fusion of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphatidylcholine vesicles. The IFC analysis result showed that the fusion rate could reach about 40% following AzoTAB addition and UV irradiation in optimized conditions. We confirmed the compatibility between AzoTAB-induced vesicle fusion and a synthetic cell-free protein translation system using green fluorescent protein as reporter. With the techniques presented, cell-sized vesicle fusion can be quantitatively analyzed and optimized, paving the way to controllable synthetic cells with fundamental biological functions like the ability to express proteins from encapsulated plasmids.


Assuntos
Brometos , Fusão de Membrana , Compostos Azo , Biossíntese de Proteínas , Compostos de Amônio Quaternário
12.
J Environ Sci (China) ; 117: 151-160, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35725067

RESUMO

Algal blooms and wastewater effluents can introduce algal organic matter (AOM) and effluent organic matter (EfOM) into surface waters, respectively. In this study, the impact of bromide and iodide on the formation of halogenated disinfection byproducts (DBPs) during chlorination and chloramination from various types of dissolved organic matter (DOM, e.g., natural organic matter (NOM), AOM, and EfOM) were investigated based on the data collected from literature. In general, higher formation of trihalomethanes (THMs) and haloacetic acids (HAAs) was observed in NOM than AOM and EfOM, indicating high reactivities of phenolic moieties with both chlorine and monochloramine. The formation of haloacetaldehydes (HALs), haloacetonitriles (HANs) and haloacetamides (HAMs) was much lower than THMs and HAAs. Increasing initial bromide concentrations increased the formation of THMs, HAAs, HANs, and HAMs, but not HALs. Bromine substitution factor (BSF) values of DBPs formed in chlorination decreased as specific ultraviolet absorbance (SUVA) increased. AOM favored the formation of iodinated THMs (I-THMs) during chloramination using preformed chloramines and chlorination-chloramination processes. Increasing prechlorination time can reduce the I-THM concentrations because of the conversion of iodide to iodate, but this increased the formation of chlorinated and brominated DBPs. In an analogous way, iodine substitution factor (ISF) values of I-THMs formed in chloramination decreased as SUVA values of DOM increased. Compared to chlorination, the formation of noniodinated DBPs is low in chloramination.


Assuntos
Desinfetantes , Poluentes Químicos da Água , Purificação da Água , Brometos , Desinfecção , Matéria Orgânica Dissolvida , Halogenação , Iodetos , Trialometanos , Poluentes Químicos da Água/análise
13.
Environ Monit Assess ; 194(8): 544, 2022 Jun 30.
Artigo em Inglês | MEDLINE | ID: mdl-35771393

RESUMO

Bromide in water can form undesirable by-products such as bromate when treated by ozonation during drinking water production. The maximum contaminant level (MCL) for bromate is 10 µg/L in most countries because it is suspected of being carcinogenic. In this paper, the geographical distribution of bromide concentration in Croatian groundwater is presented covering the Pannonian basin and the Dinarides (Adriatic Sea). Groundwater in Croatian wellfields predominantly has a bromide content of less than 50 µg/L and thus belongs to the group with low potential for bromate formation. Waters with higher bromide concentrations were found mainly in the coastal regions of Croatia, probably due to seawater intrusion. In addition, bromide concentration showed a positive correlation of 0.6 with conductivity, chloride, and sodium. In addition, the potential of 123 groundwaters analyzed in this study to form bromate when treated with ozone was evaluated using models available in the literature. Analysis of water from Croatian wellfields indicated that the potential for bromate formation above the MCL during ozonation was relatively low. The models used from the literature predicted quite different values of bromate concentration when applied to the same water, with some values exceeding those theoretically possible. Selected models may be useful as a general warning of possible bromate formation.


Assuntos
Água Potável , Água Subterrânea , Ozônio , Poluentes Químicos da Água , Purificação da Água , Bromatos/análise , Brometos/análise , Croácia , Água Potável/análise , Monitoramento Ambiental , Ozônio/análise , Poluentes Químicos da Água/análise
14.
Sci Total Environ ; 841: 156694, 2022 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-35714740

RESUMO

Ozonation of wastewater can reduce the release of organic micropollutants, but may result in the formation of undesirable by-products, such as bromate from bromide. Bromide is one of the most abundant ions in seawater, the primary precursor of bromate during ozonation, and the end product in microbial bromate reduction. Investigations were carried out to compare the concentration of bromide in wastewater in coastal and non-coastal catchment areas, to monitor bromate formation during ozonation, and to assess the potential for subsequent bromate reduction with denitrifying carriers. Higher bromide concentrations were systematically observed in wastewater from coastal catchment areas (0.2-2 mg Br-/L) than in wastewater from non-coastal areas (0.06-0.2 mg Br-/L), resulting in elevated formation of bromate during ozonation. Subsequent investigations of bromate reduction in contact with denitrifying carriers from two full-scale moving bed biofilm reactors (MBBRs) showed that 80 % of the bromate formed during ozonation could be reduced to bromide in 60 min with first-order rate constants of 0.3-0.8 L/(gbiomass·h). Flow-through experiments with denitrifying carriers also showed that combined reduction of bromate and nitrate could be achieved below a concentration of 2 mg NOx--N/L. These findings indicate that bromide-rich wastewater is more likely to be of concern when using ozonation in coastal than in non-coastal areas, and that bromate and nitrate reduction can be combined in a single biofilm reactor.


Assuntos
Ozônio , Poluentes Químicos da Água , Purificação da Água , Bromatos/análise , Brometos , Nitratos , Águas Residuárias , Poluentes Químicos da Água/análise , Purificação da Água/métodos
15.
Org Lett ; 24(24): 4322-4327, 2022 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-35686818

RESUMO

The nickel-catalyzed reductive cross-coupling reaction of acyl chloride with racemic secondary α-trifluoromethyl bromide has been developed. By this chemistry, a series of structurally interesting chiral α-CF3 carbonyl compounds could be accessed with great enantioselectivity and good functional group tolerance. The study of late-stage transformation indicated that this chemistry could be used as the robust method to prepare products that contain a bioactive motif. Furthermore, the importance of the α-trifluoromethyl group to this reaction has been illustrated by control experiments.


Assuntos
Cetonas , Níquel , Brometos , Catálise , Cloretos , Halogênios , Cetonas/química , Estrutura Molecular , Níquel/química , Estereoisomerismo
16.
Org Lett ; 24(26): 4750-4755, 2022 07 08.
Artigo em Inglês | MEDLINE | ID: mdl-35766376

RESUMO

An operationally simple and practical method is disclosed to achieve the difunctionalization of styrenes, generating fluorinated benzyl bromides via a photoinduced atom transfer radical addition process. The developed method is mild, atom-economical, cost-effective, employs very low photocatalyst loading (1000 ppm), and is highly compatible with a broad range of functional groups on styrene. The versatility of the fluorinated benzyl bromides is demonstrated through their derivatization to a variety of valuable compounds.


Assuntos
Brometos , Estirenos , Compostos de Benzil , Catálise
17.
J Environ Sci (China) ; 117: 28-36, 2022 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-35725080

RESUMO

The UV/Cl2 process is commonly used to achieve a multiple-barrier disinfection and maintain residuals. The study chose methylamine as a precursor to study the formation of high-toxic halonitromethanes (HNMs) in the presence of bromide ions (Br-) during UV/Cl2 disinfection. The maximum yield of HNMs increased first and then decreased with increasing concentration of Br-. An excessively high concentration of Br- induced the maximum yield of HNMs in advance. The maximum bromine incorporation factor (BIF) increased, while the maximum bromine utilization factor (BUF) decreased with the increase of Br- concentration. The maximum yield of HNMs decreased as pH value increased from 6.0 to 8.0 due to the deprotonation process. The BUF value remained relatively higher under an acidic condition, while pH value had no evident influence on the BIF value. The maximum yield of HNMs and value of BUF maximized at a Cl2:Br- ratio of 12.5, whereas the BIF value remained relatively higher at low Cl2:Br- ratios (2.5 and 5). The amino group in methylamine was first halogenated, and then released into solution as inorganic nitrogen by the rupture of C-N bond or transformed to nitro group by oxidation and elimination pathways. The maximum yield of HNMs in real waters was higher than that in pure water due to the high content of dissolved organic carbon. Two real waters were sampled to verify the law of HNMs formation. This study helps to understand the HNMs formation (especially brominated species) when the UV/Cl2 process is adopted as a disinfection technique.


Assuntos
Desinfetantes , Poluentes Químicos da Água , Purificação da Água , Brometos/química , Bromo , Cloro/química , Desinfetantes/química , Desinfecção/métodos , Halogenação , Metilaminas , Poluentes Químicos da Água/análise , Purificação da Água/métodos
18.
Water Res ; 220: 118643, 2022 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-35667166

RESUMO

For the potable reuse of municipal wastewater effluent, carbon based advanced treatment (CBAT) using coagulation, ozonation, biofiltration and/or granular activated carbon (GAC) adsorption is a promising approach for controlling disinfection byproduct (DBP) formation. However, CBAT can also favor a shift in DBP formation to more toxic brominated DBP species. To protect public health, treatment-specific DBP formation and speciation trends need to be identified and understood. First, this study systematically evaluated the treatment of six wastewater effluents with four CBAT process trains (experimental n was 55) and measured DBP formation and speciation trends. Overall, CBAT decreased DBP formation by >90% and GAC preferentially removed highly-reactive effluent organic matter as indicated by lower yields of both highly-forming and highly-toxic classes of carbonaceous and nitrogenous DBPs. Since GAC treatment also induced systematic speciation changes by increasing the ratio of bromide to dissolved organic matter, the second part of this study focused on understanding the health impacts of DBP speciation changes on calculated additive toxicity (CAT). Based on the evaluation of 20 DBPs, measured using established methods, the CAT values from cyto- and genotoxicity metrics decreased by as much as 85% due to high levels of precursor removal by GAC. Expanding the evaluation to include 52 DBPs, measured using more extensive analytical methods, resulted in the same conclusions. This study also developed a "speciation potency" metric, that re-scales class-by-class speciation trends using toxic potency factors (e.g., cytotoxicity [LC50]). The observed shifts in DBP speciation after treatment increased the class-level toxic potency factors by up to a factor of 4; a greater amount of precursor removal is required for treatment to reduce toxicity, which was achieved with CBAT trains. This proposed approach of combining speciation potency with DBP yields enables evaluation of DBP-associated risk with easily measured surrogates (i.e., bromide and dissolved organic carbon [DOC]). By identifying and quantitatively comparing DBP formation and speciation trends over multiple wastewater effluents and treatment trains, this study demonstrates that CBAT can be a robust approach to DBP precursor removal for potable reuse.


Assuntos
Desinfetantes , Poluentes Químicos da Água , Purificação da Água , Brometos , Carvão Vegetal , Desinfecção , Águas Residuárias
19.
Methods Mol Biol ; 2487: 361-375, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35687247

RESUMO

Halides are substrates and products of a number of biotechnologically important enzymes like dehalogenases, halide methyltransferases, and halogenases. Therefore, the determination of halide concentrations in samples is important. The classical methods based on mercuric thiocyanate are very dangerous, produce hazardous waste, and do not discriminate between chloride, bromide, and iodide. In this chapter, we describe a detailed protocol for the determination of halide concentrations based on the haloperoxidase-catalyzed oxidation of halides. The resulting hypohalous acids are detected using commercially available colorimetric or fluorimetric probes. The biocatalytic nature of the assays allows them to be implemented in one-pot cascade reactions with halide-generating enzymes. Since chloride is ubiquitous in biological systems, we also describe convenient photometric assays for the selective detection of bromide and iodide in the presence of chloride, obviating the need for laborious dialyses to obtain halide-free enzymes and reagents.


Assuntos
Brometos , Iodetos , Cloretos , Halogênios , Diálise Renal
20.
Nat Commun ; 13(1): 2588, 2022 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-35546155

RESUMO

Disulfides are widely found in natural products and find a wide range of applications in life sciences, materials chemistry and other fields. The preparation of disulfides mainly rely on oxidative couplings of two sulfur containing compounds. This strategy has many side reactions and other shortcomings. Herein, we describe the reductive nickel-catalyzed cross-electrophile coupling of unactivated alkyl bromides with symmetrical alkyl- and aryltetrasulfides to form alkyl-alkyl and aryl-alkyl unsymmetrical disulfides. This approach for disulfide synthesis is practical, relies on easily available, unfunctionalized substrates, and is scalable. We investigated the mechanism of this transformation and found that the tetrasulfide compound does not selectively break the central S-S bond, but regio-selectively generates trisulfide intermediates.


Assuntos
Dissulfetos , Níquel , Brometos , Catálise , Níquel/química
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