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1.
Molecules ; 28(2)2023 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-36677890

RESUMO

Cytochrome P450 OleP catalytic activity is strongly influenced by its structural dynamic conformational behavior. Here, we combine equilibrium-binding experiments with all-atom molecular dynamics simulations to clarify how different environments affect OleP conformational equilibrium between the open and the closed-catalytic competent-forms. Our data clearly show that at high-ionic strength conditions, the closed form is favored, and, very interestingly, different mechanisms, depending on the chemistry of the cations, can be used to rationalize such an effect.


Assuntos
Sistema Enzimático do Citocromo P-450 , Sais , Sistema Enzimático do Citocromo P-450/metabolismo , Conformação Proteica , Simulação de Dinâmica Molecular
2.
Sci Rep ; 13(1): 177, 2023 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-36604573

RESUMO

Here, we present the results related to a new unique terrestrial ecosystem found in an englacial hypersaline brine found in Northern Victoria Land (Antarctica). Both the geochemistry and microbial (prokaryotic and fungal) diversity revealed an unicity with respect to all the other known Antarctic brines and suggested a probable ancient origin mainly due a progressive cryoconcentration of seawater. The prokaryotic community presented some peculiarities, such as the occurrence of sequences of Patescibacteria (which can thrive in nutrient-limited water environments) or few Spirochaeta, and the presence of archaeal sequences of Methanomicrobia closely related to Methanoculleus, a methanogen commonly detected in marine and estuarine environments. The high percentage (35%) of unassigned fungal taxa suggested the presence of a high degree of undiscovered diversity within a structured fungal community (including both yeast and filamentous life forms) and reinforce the hypothesis of a high degree of biological uniqueness of the habitat under study.


Assuntos
Ecossistema , Euryarchaeota , Regiões Antárticas , Sais , Bactérias
3.
Molecules ; 28(1)2023 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-36615579

RESUMO

There has been a great focus on halogen-bonding as a unique interaction between electron-deficient halogen atoms with Lewis basic moieties. Although the application of halogen-bonded atoms in organic chemistry has been eagerly researched in these decades, the development of chiral molecules with halogen-bonding functionalities and their utilization in asymmetric catalysis are still in the\ir infancy. We have previously developed chiral halonium salts with amide functionalities, which behaved as excellent catalysts albeit in only two reactions due to the lack of substrate activation abilities. In this manuscript, we have developed chiral halonium salts with an N-nitrosamine moiety and applied them to the Mannich reaction of isatin-derived ketimines with malonic esters. The study focused on our novel bromonium salt catalyst which provided the corresponding products in high yields with up to 80% ee. DFT calculations of the chiral catalyst structure suggested that the high asymmetric induction abilities of this catalyst are due to the Lewis basic role of the N-nitrosamine part. To the best of our knowledge, this is the first catalytic application of N-nitrosamines.


Assuntos
Halogênios , Nitrosaminas , Bromo , Sais , Cloreto de Sódio , Cloreto de Sódio na Dieta , Catálise
4.
Molecules ; 28(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36615648

RESUMO

In order to broaden the study of energetic cations, a cation 3,5-diamino-4H-pyrazol-4-one oxime (DAPO) with good thermal stability was proposed, and its three salts were synthesized by a simple and efficient method. The structures of the three salts were verified by infrared spectroscopy, mass spectrometry, elemental analysis, and single crystal X-ray diffraction. The thermal stabilities of the three salts were verified by differential scanning calorimetry and thermos-gravimetric analysis. DAPO-based energetic salts are analysed using a variety of theoretical techniques, such as 2D fingerprint, Hirshfeld surface, and non-covalent interaction. Among them, the energy properties of perchlorate (DAPOP) and picrate (DAPOT) were determined by EXPLO5 program combined with the measured density and enthalpy of formation. These compounds have high density, acceptable detonation performance, good thermal stability, and satisfactory sensitivity. The intermolecular interactions of the four compounds were studied by Hirshfeld surface and non-covalent interactions, indicating that hydrogen bonds and π-π stacking interactions are the reasons for the extracellular properties of perchlorate (DAPOP) and picrate (DAPOT), indicating that DAPO is an optional nitrogen-rich cation for the design and synthesis of novel energetic materials with excellent properties.


Assuntos
Percloratos , Sais , Picratos , Oximas
5.
ACS Macro Lett ; 12(1): 86-92, 2023 01 17.
Artigo em Inglês | MEDLINE | ID: mdl-36595317

RESUMO

There is growing interest in polymers with high ionic conductivity for applications including batteries, fuel cells, and separation membranes. However, measuring ion diffusion in polymers can be challenging, requiring complex procedures and instrumentation. Here, a simple strategy to study ion diffusion in polymers is presented that utilizes ion-chromic spiropyan as an indicator to measure the diffusion of LiTFSI, KTFSI, and NaTFSI within poly(ethylene oxide)-based polymer networks. These systems are selected, as these are common ions and polymers used in energy storage applications, however, the approach described is not specific to materials for energy storage. Specifically, to enabling the study of ion diffusion, these salts cause the spiropyran to undergo an isomerization reaction, which results in a significant color change. This colorimetric response enables the determination of the diffusion coefficients of these ions within films of these polymers simply by optically tracking the spatial-temporal evolution of the isomerization product within the film and fitting the data to the relevant diffusion equations. The simplicity of the method makes it amenable to the study of ion diffusion in polymers under a range of conditions, including various temperatures and under macroscopic deformation.


Assuntos
Polímeros , Sais , Íons , Temperatura , Difusão
6.
Chemosphere ; 316: 137737, 2023 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36608877

RESUMO

Dissolved organic matter (DOM) is distributed ubiquitously in water bodies. Ferric ions can flocculate DOM to form stable coprecipitates; however, Al(III) may alter the structures and stability of Fe-DOM coprecipitates. This study aimed to examine the coprecipitation of Fe, Al, and DOM as well as structural developments of Fe-DOM coprecipitates in relation to changes in Fe/Al ratios and pHs. The results showed that the derived Fe/Al/DOM-coprecipitates could be classified into three categories: (1) at pH 3.0 and 4.5, the corner-sharing FeO6 octahedra associated with Fe-C bonds with Fe/(Fe + Al) ratios ≥0.5; (2) the Fe-C bonds along with single Fe octahedra having Fe/(Fe + Al) ratios of 0.25; (3) at pH 6.0, the ferrihydrite-like Fe domains associated with Fe-C bonds with Fe/(Fe + Al) ratios ≥0.5. At pH 3.0, the Fe and C stability of the coprecipitates increased with increasing Al proportions; nonetheless, pure Al-DOM coprecipitates were unstable even if they exhibited the maximum ability for DOM removal. The associations of Al-DOM complexes and/or DOM-adsorbed Al domains with external surfaces of Fe domain or Fe-DOM coprecipitates may stabilize DOM, leading to lower C solubilization at pH 4.5. Although the preferential formation of Fe/Al hydroxides decreased Fe/Al solubilization at pH 6.0, adsorption instead of coprecipitation of DOM with Fe/Al hydroxides may decrease C stabilization in the coprecipitates. Aluminum cations inhibit DOM releases from Fe/Al/DOM-coprecipitates, promoting the treatment and reuse efficiencies of wastewater and resolving water shortages. This study demonstrates that Al and solution pH greatly affect the structural changes of Fe-DOM coprecipitates and indirectly control the dynamics of Fe, Al, and C concentrations in water.


Assuntos
Matéria Orgânica Dissolvida , Sais , Ferro/química , Compostos Férricos/química , Hidróxidos/química , Água
7.
MAbs ; 15(1): 2169440, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36705325

RESUMO

Solutions of monoclonal antibodies (mAbs) can show increased viscosity at high concentration, which can be a disadvantage during protein purification, filling, and administration. The viscosity is determined by protein-protein-interactions, which are influenced by the antibody's sequence as well as solution conditions, like pH, buffer type, or the presence of salts and other excipients. To predict viscosity, experimental parameters, like the diffusion interaction parameter (kD), or computational tools harnessing information derived from primary sequence, are often used, but a reliable predictive tool is still missing. We present a modeling approach employing artificial neural networks (ANNs) using experimental factors combined with simulation-derived parameters plus viscosity data from 27 highly concentrated (180 mg/mL) mAbs. These ANNs can be used to predict if mAbs exhibit problematic viscosity at distinct concentrations or to model viscosity-concentration-curves.


Assuntos
Anticorpos Monoclonais , Sais , Viscosidade , Simulação por Computador , Redes Neurais de Computação , Soluções
8.
Water Environ Res ; 95(1): e10829, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-36694307

RESUMO

Facile techniques to fabricate the nanofiltration membranes with ideal molecular sieving is one of the most interesting subjects in membrane separation technology. In this study, the application of modified graphene oxide (GO) with triethylenetetramine (TETA), CuFe2 O4 , and acetic acid (AC) (supported GO-TETA-CuFe2 O4 @AC) as a supported protic ionic liquid (PIL) modifier for polyethersulfone (PES) membrane was evaluated to approve the improvement of anti-fouling properties and wastewater rejection of the fabricated membranes. To enhance the key properties of graphene oxide, it was modified by hydrophilic nanomaterials (TETA-CuFe2 O4 ). High flux and promising flux recovery ratio (up to 95% compared to the unmodified membrane) can be observed in the modified membranes. The modified membranes by GO-TETA-CuFe2 O4 @AC were studied at optimum concentrations (0.5 wt.%) for salt rejection and different dyes. The obtained data indicated that the modified membranes by GO-TETA-CuFe2 O4 @AC indicated higher salt removal (up to 97% for BaCl2 than the unmodified membrane), which was related to the efficient modification. The obtained pure water flux (PWF) for bare and optimal modified membrane from 13.11 to 27.87 kg/m2 ·h, respectively. To exact evaluate the effect of membrane modification on performance examination, the modified membranes were evaluated for chlorine resistance testing. This study aimed to develop cost-effective nanofiltration (NF) membranes with high anti-fouling properties and to determine the maximum filtration capacity of in-time dyes and salts in effluents. PRACTITIONER POINTS: A GO-TETA-CuFe2O4 mixed matrix membrane was prepared for removal of salts and dyes. The effect of GO-TETA-CuFe2O4 enhanced the hydrophilicity and porosity. The membrane exhibited superior antifouling properties and ions rejection.


Assuntos
Incrustação Biológica , Líquidos Iônicos , Humanos , Sais , Incrustação Biológica/prevenção & controle , Corantes , Cloreto de Sódio , Membranas Artificiais
9.
J Chem Phys ; 158(3): 034504, 2023 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-36681647

RESUMO

The ability of salts to change the macroscopic viscosity of their aqueous solutions is described by the Jones-Dole equation with B-coefficient for the linear concentration term. The sign and value of this coefficient are often considered as a measure of the salt's structure-making/breaking ability, while the validity of this assignment is still under discussion. Here, by applying Raman and Brillouin scattering spectroscopy to various salts from the Hofmeister series, we studied a possible relation between macroscopic Jones-Dole's B-coefficient and the microscopic dynamic response. Raman spectroscopy provides information about molecular vibrations and Brillouin spectroscopy about acoustic phonons with wavelengths of hundreds of nanometers. It has been found that Jones-Dole's B-coefficient correlates linearly with the coefficients, describing the concentration dependences of the average OH stretching frequency, real and imaginary parts of gigahertz elastic modulus. These relationships have been interpreted to mean that the OH stretching frequency is a measure of the ion-induced changes in the water network that cause changes in both viscosity and gigahertz relaxation. Depolarized inelastic light scattering revealed that the addition of structure-making ions not only changes the frequency of the relaxation peak but also increases the low-frequency part of the relaxation susceptibility. It was shown that the ion-induced increase in the gigahertz elastic modulus can be described by changes in the relaxational susceptibility without a noticeable change in the instantaneous elastic modulus. The isotropic Raman contribution associated with the tetrahedral-like environment of H2O molecule does not correlate with Jones-Dole's B-coefficient, suggesting a minor influence of these tetrahedral-like configurations on viscosity.


Assuntos
Sais , Água , Módulo de Elasticidade , Água/química , Íons , Análise Espectral Raman
10.
Sci Adv ; 9(3): eadf8706, 2023 Jan 20.
Artigo em Inglês | MEDLINE | ID: mdl-36662853

RESUMO

In the Mooser-Pearson diagram, binary ionic compoundss form into nonpolar symmetrical structures with high coordination numbers, while wurtzite structures should appear in the covalent region. Their tetrahedral bonding configurations break the inversion symmetry, with polarizations almost unswitchable due to the high barriers of abrupt breaking and reformation of covalent bonds. Here, through first-principles calculations, we find some exceptional cases of highly ionic ferroelectric binary salts such as lithium halides, which may form into wurtzite structures with covalent-like sp3 bondings, and the origin of these abnormal formations is clarified. Their high polarizations induced by symmetry breaking are switchable, with much smoother switching pathway refrained from abrupt bond breaking due to the long-range feature of Coulomb interactions. These covalent-like ionic bondings do reduce not only their ferroelectric switching barriers but also the phase transition barriers between polar and nonpolar phases, rendering high performance in applications such as nonvolatile memory and energy storage.


Assuntos
Inversão Cromossômica , Sais , Humanos , Fenômenos Biofísicos , Íons , Lítio
11.
Int J Mol Sci ; 24(2)2023 Jan 11.
Artigo em Inglês | MEDLINE | ID: mdl-36674923

RESUMO

This work reports the synthesis, structural and thermal analysis, and in vitro evaluation of the antimicrobial activity of two new organic salts (OSs) derived from the antimycobacterial drug clofazimine and the fluoroquinolones ofloxacin or norfloxacin. Organic salts derived from active pharmaceutical ingredients (API-OSs), as those herein disclosed, hold promise as cost-effective formulations with improved features over their parent drugs, thus enabling the mitigation of some of their shortcomings. For instance, in the specific case of clofazimine, its poor solubility severely limits its bioavailability. As compared to clofazimine, the clofazimine-derived OSs now reported have improved solubility and thermostability, without any major deleterious effects on the drug's bioactivity profile.


Assuntos
Clofazimina , Fluoroquinolonas , Fluoroquinolonas/farmacologia , Clofazimina/farmacologia , Clofazimina/química , Sais , Antibacterianos/farmacologia , Antibacterianos/química , Solubilidade
12.
Int J Mol Sci ; 24(2)2023 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-36675316

RESUMO

It was found that alkyl carbocations, when their salts are dissolved in common organochlorine solvents, decompose to unsaturated vinyl-type carbocations that are stabler in solutions. This is a convenient method for obtaining salts of vinyl cations and their solutions for further research.


Assuntos
Sais , Cátions , Solventes
13.
Org Lett ; 25(1): 272-276, 2023 01 13.
Artigo em Inglês | MEDLINE | ID: mdl-36594721

RESUMO

Preparation of S-aryl xanthates via transition-metal-catalyzed or SNAr reactions is complicated by their further transformations under the utilized conditions. In contrast, S-arylation of potassium O-alkyl xanthates with diaryliodonium salts proceeds under mild conditions, enabling access to substituted S-aryl xanthates. The method exhibits good functional group tolerance and can be applied to the late-stage C-H functionalization of drug molecules. Divergent transformations of the resulting S-aryl xanthates provide rapid access to a range of medicinal chemistry-relevant organosulfur compounds.


Assuntos
Potássio , Sais , Estrutura Molecular , Oniocompostos
14.
Food Chem ; 409: 135263, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-36592599

RESUMO

In this study, the thermal gelation and digestion properties of hen egg white (hen EW) proteins with different salts were investigated. Results show that the addition of neutral salt - sodium chloride (NaCl) decreased the gel hardness/resilience, increased gel lightness, aggregated particle size and digestibility of hen EW proteins significantly. In contrast, alkaline salts - phosphate and carbonate addition increased the gel resilience and strain tolerance as well as reduced the aggregated particle size and gel lightness of hen EW proteins due to the increase of solution pH and negative charge. Correlation analysis shows that the digestibility of hen EW gels was affected by gel viscoelasticity, molecule forces and texture. In conclusion, thermal gelation properties of hen EW proteins could be modulated by salts with different pH/ionic strength, and thus affected the protein digestion and peptide released.


Assuntos
Clara de Ovo , Sais , Clara de Ovo/química , Cloreto de Sódio/química , Proteínas do Ovo/química , Digestão , Géis/química
15.
Food Chem ; 409: 135272, 2023 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-36623357

RESUMO

Amino-modified Zn/Fe bimetallic metal-organic frameworks (NH2-Zn/Fe-MIL-88) were synthesized using a one-step solvothermal method with FeCl3·6H2O and Zn(NO3)2·6H2O as metal salts and 2-aminoterephthalic acid as organic ligand. The morphology of NH2-Zn/Fe-MIL-88 can be regulated from octahedral-like to spindle-like with changing molar ratios of metal salts. Using NH2-Zn/Fe-MIL-88 as sorbent, a dispersive solid-phase extraction with putting sorbents into sample solution to extract targets was developed to preconcentrate phytohormones in vegetables. To study the extraction efficiency, a series of NH2-Zn/Fe-MIL-88s with varying molar ratios of metal salts were prepared. The results indicated that NH2-Zn/Fe-MIL-88(1) presented the highest extraction efficiency (82.6 %-98.1 %) to phytohormones among all prepared NH2-Zn/Fe-MIL-88(x). The limits of detection were calculated at 0.07-0.15 ng/mL. The adsorption isotherms and kinetic parameters of NH2-Zn/Fe-MIL-88 for phytohormones were conformed to Langmuir and pseudo-second-order models. The NH2-Zn/Fe-MIL-88 as sorbent combined with HPLC was applied to detect phytohormones in cucumber and tomato samples.


Assuntos
Estruturas Metalorgânicas , Verduras , Sais , Reguladores de Crescimento de Plantas , Extração em Fase Sólida , Zinco
16.
J Chromatogr A ; 1689: 463757, 2023 Jan 25.
Artigo em Inglês | MEDLINE | ID: mdl-36628807

RESUMO

The olefin/paraffin selectivity offered by ionic liquid (IL) stationary phases can be enhanced through the addition of silver(I) ion, which is well-known to undergo selective complexation with unsaturated compounds. However, such stationary phases often suffer from the loss of chromatographic selectivity as silver(I) ion can be reduced to elemental silver. To maintain the separation performance of silver(I) ion/IL stationary phases, an understanding of factors and conditions that promote the reduction of silver(I) ion is needed. In this study, capillary gas chromatography columns featuring a stationary phase consisting of the 1-decyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([C10MIM+][NTf2-]) IL impregnated with [Ag+][NTf2-] were examined to investigate the effects of temperature, hydrogen content in exposure gas stream, and time of heating/exposure events on olefin selectivity. Retention factors of representative analytes, such as C6 olefins and paraffins as well as aromatic compounds, were measured after subjecting the columns to the aforementioned conditions, followed by an evaluation of selectivity factors over time. Selectivity factors of olefins and aromatic compounds were observed to decrease significantly when the stationary phases were heated to temperatures higher than 110°C as well as being subjected to mixed gas streams containing greater than 50 mol% of hydrogen. As constant column heating temperatures were applied under exposure gas mixtures containing hydrogen and nitrogen, a gradual decrease in analyte selectivity factors was observed under prolonged periods of time. However, application of a ternary gas mixture comprised of 25/50/25 mol% hydrogen/nitrogen/methane resulted in an increase in the 3-hexyne/cis-2-hexene selectivity when measured at 120°C for 60 h, due to a smaller decrease in the retention factor of 3-hexyne compared to cis-2-hexene.


Assuntos
Líquidos Iônicos , Líquidos Iônicos/química , Parafina , Prata/química , Sais , Alcenos , Cromatografia Gasosa/métodos
17.
Chem Commun (Camb) ; 59(6): 764-767, 2023 Jan 17.
Artigo em Inglês | MEDLINE | ID: mdl-36541669

RESUMO

An efficient photoredox-catalyzed three-component coupling reaction of aryl sulfonium salts, carbon dioxide and amines has been developed for the first time. This reaction provides a new strategy for the synthesis of a range of valuable O-aryl carbamates from readily available arenes via a site-selective thianthrenation/carbamoyloxylation two-step process. Mild conditions, broad substrate scope and good functional group tolerance are the features of the transformation. The synthetic utility of the method was demonstrated by the late-stage modification of bioactive molecules and pharmaceuticals.


Assuntos
Aminas , Carbamatos , Dióxido de Carbono , Sais , Catálise
18.
J Environ Radioact ; 257: 107083, 2023 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-36516518

RESUMO

Enrichment of heavy isotopes of hydrogen (D, 3H) and oxygen (18О) is observed in water samples collected from open brine storage of Kalush-Golinsky deposit. The brine storage facilities were formed during the operation of the Kalush-Golynsky deposit of potassium salts and after its decommissioning. Enrichment of isotopes is also observed in groundwater samples, collected from wells located along with downstream groundwater from brine storage facilities. The analysis of levels of influence of possible sources of chemical pollution of groundwater (waters of the Dombrovsky quarry, tailings and sludge storage, salt dumps, saline soils) and correlation relationships between isotopes and groundwater mineralization have been determined by statistical processing of geochemical data.


Assuntos
Água Subterrânea , Monitoramento de Radiação , Poluentes Químicos da Água , Sais/análise , Sais/química , Potássio/análise , Poluentes Químicos da Água/análise , Monitoramento Ambiental , Água Subterrânea/química , Isótopos de Oxigênio/análise
19.
J Org Chem ; 88(1): 534-539, 2023 Jan 06.
Artigo em Inglês | MEDLINE | ID: mdl-36534447

RESUMO

We report an efficient alkyl transfer strategy for the direct ß-alkylation of chalcones using commercially available alkyl bromides as alkyl reagents. In this transformation, the ortho-phosphanyl substituent in the chalcones is crucial for controlling their reactivity and selectivity. It also serves as a reliable alkyl transfer shuttle to transform electrophilic alkyl bromides into nucleophilic alkyl species in the form of quaternary phosphonium salts and transfer the alkyl group effectively to the ß-position of the chalcones. This alkyl transfer strategy can be further extended to the alkenylation of ortho-phosphanyl benzaldehydes to assemble functionalized polyenes.


Assuntos
Chalconas , Brometos , Catálise , Sais , Alquilação
20.
Eur J Med Chem ; 246: 114993, 2023 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-36495631

RESUMO

Solubility-driven optimization of the salts of nitro benzothiopyranone 1, which targets DprE1, led to an antimycobacterial preclinical candidate 2. Five pharmaceutically acceptable salts, including the maleate (2), fumarate (3), citrate (4, 5), and l-malate (6) of compound 1, were prepared via the salt formation reaction and evaluated for their physicochemical and pharmacokinetic properties. Compared with 1, all the target salts exhibited greatly increased aqueous solubility and improved oral bioavailability in mice. Maleate salt 2, which displayed higher chemical stability and lower log P, showed substantially improved bioavailability in rats and a much better in vivo effect compared with free base 1 at the same dose. The X-ray crystal structure of 2 revealed that the exposed hydrophilic piperazine-maleate moiety in the crystal structure cell may be critical in increasing the solubility of 2. Thus, this maleate salt 2 overcame the poor druggability of benzothiopyranone derivatives and was identified as a promising preclinical candidate for treating tuberculosis.


Assuntos
Mycobacterium tuberculosis , Animais , Camundongos , Ratos , Maleatos/química , Maleatos/farmacologia , Piperazina/farmacologia , Sais/química , Solubilidade , Fumaratos/química , Fumaratos/farmacologia
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