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1.
Int J Mol Sci ; 25(13)2024 Jul 03.
Artigo em Inglês | MEDLINE | ID: mdl-39000410

RESUMO

Alzheimer's disease (AD) is a multifactorial and fatal neurodegenerative disorder. Acetylcholinesterase (AChE) plays a key role in the regulation of the cholinergic system and particularly in the formation of amyloid plaques; therefore, the inhibition of AChE has become one of the most promising strategies for the treatment of AD, particularly concerning AChE inhibitors that interact with the peripheral anionic site (PAS). Ceanothic acid isolated from the Chilean Rhamnaceae plants is an inhibitor of AChE through its interaction with PAS. In this study, six ceanothic acid derivatives were prepared, and all showed inhibitory activity against AChE. The structural modifications were performed starting from ceanothic acid by application of simple synthetic routes: esterification, reduction, and oxidation. AChE activity was determined by the Ellmann method for all compounds. Kinetic studies indicated that its inhibition was competitive and reversible. According to the molecular coupling and displacement studies of the propidium iodide test, the inhibitory effect of compounds would be produced by interaction with the PAS of AChE. In silico predictions of physicochemical properties, pharmacokinetics, drug-likeness, and medicinal chemistry friendliness of the ceanothane derivatives were performed using the Swiss ADME tool.


Assuntos
Acetilcolinesterase , Domínio Catalítico , Inibidores da Colinesterase , Desenho de Fármacos , Inibidores da Colinesterase/química , Inibidores da Colinesterase/farmacologia , Acetilcolinesterase/química , Acetilcolinesterase/metabolismo , Humanos , Doença de Alzheimer/tratamento farmacológico , Cinética , Simulação de Acoplamento Molecular , Relação Estrutura-Atividade , Ânions/química , Animais
2.
J Enzyme Inhib Med Chem ; 39(1): 2372731, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-39012078

RESUMO

This study refers to the intricate world of Acinetobacter baumannii, a resilient pathogenic bacterium notorious for its propensity at antibiotic resistance in nosocomial infections. Expanding upon previous findings that emphasised the bifunctional enzyme PaaY, revealing unexpected γ-carbonic anhydrase (CA) activity, our research focuses on a different class of CA identified within the A. baumannii genome, the ß-CA, designated as 𝛽-AbauCA (also indicated as CanB), which plays a crucial role in the resistance mechanism mediated by AmpC beta-lactamase. Here, we cloned, expressed, and purified the recombinant 𝛽-AbauCA, unveiling its distinctive kinetic properties and inhibition profile with inorganic anions (classical CA inhibitors). The exploration of 𝛽-AbauCA not only enhances our understanding of the CA repertoire of A. baumannii but also establishes a foundation for targeted therapeutic interventions against this resilient pathogen, promising advancements in combating its adaptability and antibiotic resistance.


Assuntos
Acinetobacter baumannii , Ânions , Antibacterianos , Inibidores da Anidrase Carbônica , Anidrases Carbônicas , Testes de Sensibilidade Microbiana , Acinetobacter baumannii/enzimologia , Acinetobacter baumannii/efeitos dos fármacos , Anidrases Carbônicas/metabolismo , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/síntese química , Ânions/farmacologia , Ânions/química , Inibidores da Anidrase Carbônica/farmacologia , Inibidores da Anidrase Carbônica/química , Inibidores da Anidrase Carbônica/síntese química , Relação Estrutura-Atividade , Relação Dose-Resposta a Droga , Estrutura Molecular
3.
J Hazard Mater ; 474: 134793, 2024 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-38850954

RESUMO

Progress in the development of biodegradable or biobased ionic liquids (ILs) has led to the design of green compounds for several applications. Herein, four biocompatible dicationic ionic liquids (DILs) with ammonium-phosphonium cations and amino acid anions were synthesized and investigated their environmental impact. The structures of the DILs were confirmed by spectral analyses (1H, 13C and 31P NMR). Furthermore, physicochemical properties such as density, viscosity and refractive index were determined. Water content, bromide content and solubility were thereafter determined as the parameters needed for further studies. Subsequently, their antifeedant activity towards economically important pests of grain in storage warehouses: the granary weevil, the confused flour beetle, and the khapra beetle was examined, showing the dependence on structure. Moreover, selected DILs were investigated for toxicity towards white mustard, Daphnia magna, and Artemia franciscana to specify the environmental impact. These studies were complemented by understand the biodegradation of DILs by bacterial communities derived from soil at the agricultural land. The result was DILs with limited environmental footprints that have great potential for further application studies.


Assuntos
Aminoácidos , Artemia , Daphnia , Líquidos Iônicos , Líquidos Iônicos/toxicidade , Líquidos Iônicos/química , Animais , Aminoácidos/química , Aminoácidos/análise , Daphnia/efeitos dos fármacos , Artemia/efeitos dos fármacos , Compostos de Amônio/química , Compostos Organofosforados/química , Cátions , Ânions/química , Meio Ambiente , Biodegradação Ambiental , Besouros/efeitos dos fármacos
4.
Anal Chem ; 96(24): 9969-9974, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38847356

RESUMO

Epinephrine (EP) is an essential catecholamine in the human body. Currently, most EP detection methods are not suitable for in vivo detection due to material limitations. An organic small molecule fluorescent probe based on a chemical cascade reaction for the detection of EP was designed. Anionic heptamethine cyanine dye was selected as a fluorescent dye because of its NIR fluorescence emission with excellent biocompatibility. The secondary amine of EP nucleophilically attacks the carbonate of the probe with its stronger nucleophilicity and further undergoes intramolecular nucleophilic cyclization to release the fluorophore. Other substances containing only primary amines or no ß-OH lack reaction competitiveness due to their weaker nucleophilicity or inability to undergo further cyclization. The fluorescence recovery of the probe was linearly related to the EP concentration of 2-75 µmol/L. The detection limit was 0.4 µmol/L. The recovery rate was 94.78-111.32%. Finally, we successfully achieved bioimaging of EP in living cells and EP analogue in nematodes.


Assuntos
Carbocianinas , Epinefrina , Corantes Fluorescentes , Corantes Fluorescentes/química , Corantes Fluorescentes/síntese química , Humanos , Epinefrina/análise , Carbocianinas/química , Animais , Imagem Óptica , Ânions/química , Ânions/análise , Caenorhabditis elegans , Limite de Detecção , Raios Infravermelhos , Células HeLa , Estrutura Molecular
5.
J Colloid Interface Sci ; 672: 244-255, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-38838632

RESUMO

HYPOTHESIS: Nonionic surfactants can counter the deleterious effect that anionic surfactants have on proteins, where the folded states are retrieved from a previously unfolded state. However, further studies are required to refine our understanding of the underlying mechanism of the refolding process. While interactions between nonionic surfactants and tightly folded proteins are not anticipated, we hypothesized that intermediate stages of surfactant-induced unfolding could define new interaction mechanisms by which nonionic surfactants can further alter protein conformation. EXPERIMENTS: In this work, the behavior of three model proteins (human growth hormone, bovine serum albumin, and ß-lactoglobulin) was investigated in the presence of the anionic surfactant sodium dodecylsulfate, the nonionic surfactant ß-dodecylmaltoside, and mixtures of both surfactants. The transitions occurring to the proteins were determined using intrinsic fluorescence spectroscopy and far-UV circular dichroism. Based on these results, we developed a detailed interaction model for human growth hormone. Using nuclear magnetic resonance and contrast-variation small-angle neutron scattering, we studied the amino acid environment and the conformational state of the protein. FINDINGS: The results demonstrate the key role of surfactant cooperation in defining the conformational state of the proteins, which can shift away or toward the folded state depending on the nonionic-to-ionic surfactant ratio. Dodecylmaltoside, initially a non-interacting surfactant, can unexpectedly associate with sodium dodecylsulfate-unfolded proteins to further impact their conformation at low nonionic-to-ionic surfactant ratio. When this ratio increases, the protein begins to retrieve the folded state. However, the native conformation cannot be fully recovered due to remnant surfactant molecules still adsorbed to the protein. This study demonstrates that the conformational landscape of the protein depends on a delicate interplay between the surfactants, ultimately controlled by the ratio between them, resulting in unpredictable changes in the protein conformation.


Assuntos
Lactoglobulinas , Desdobramento de Proteína , Soroalbumina Bovina , Dodecilsulfato de Sódio , Tensoativos , Tensoativos/química , Humanos , Lactoglobulinas/química , Desdobramento de Proteína/efeitos dos fármacos , Dodecilsulfato de Sódio/química , Bovinos , Soroalbumina Bovina/química , Animais , Hormônio do Crescimento Humano/química , Ânions/química , Redobramento de Proteína/efeitos dos fármacos , Conformação Proteica , Glucosídeos
6.
Environ Sci Technol ; 58(26): 11791-11801, 2024 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-38871647

RESUMO

The effect of aqueous solution chemistry on the ionic hydration structure and its corresponding nanofiltration (NF) selectivity is a research gap concerning ion-selective transport. In this study, the hydration distribution of two typical monovalent anions (Cl- and NO3-) under different aqueous solution chemical conditions and the corresponding transmembrane selectivity during NF were investigated by using in situ liquid time-of-flight secondary ion mass spectrometry in combination with molecular dynamics simulations. We demonstrate the inextricable link between the ion hydration structure and the pore steric effect and further find that ionic transmembrane transport can be regulated by breaking the balance between the hydrogen bond network (i.e., water-water) and ion hydration (i.e., ion-water) interactions of hydrated ion. For strongly hydrated (H2O)nCl- with more intense ion-water interactions, a higher salt concentration and coexisting ion competition led to a larger hydrated size and, thus, a higher ion rejection by the NF membrane, whereas weakly hydrated (H2O)nNO3- takes the reverse under the same conditions. Stronger OH--anion hydration competition resulted in a smaller hydrated size of (H2O)nCl- and (H2O)nNO3-, showing a lower observed average hydration number at pH 10.5. This study deepens the long-overlooked understanding of NF separation mechanisms, concerning the hydration structure.


Assuntos
Filtração , Água/química , Íons , Simulação de Dinâmica Molecular , Soluções , Ânions/química
7.
Int J Biol Macromol ; 273(Pt 1): 132788, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38942669

RESUMO

Dye wastewater poses a serious threat to the environment and human health, necessitating sustainable degradation methods. In this study, Na-based Montmorillonite (MMT) was exfoliated using different ionic liquids ([C16MIM][Cl], [C16MIM][BF4], [C16MIM][PF6]), and silver nanoparticles (Ag NPs) were green-synthesized using hydroxypropyl cellulose (HPC). The HPC significantly enhanced the dispersion of MMT in the hydrogel. By introducing lauryl methacrylate (LMA), a hydrophobic associative network was constructed in PAM/LMA/HPC/MMT@ILs&Ag NPs hydrogel. This hydrogel demonstrated outstanding mechanical properties, with a stress of 833.21 kPa, strain of 3300 %, and toughness of 14.36 MJ/m3. It also exhibited excellent catalytic activity, with a rate constant of 0.83 min-1 for 4-nitrophenol degradation at 28 °C. The effects of temperature and catalyst concentration on the catalytic reaction were systematically investigated. This study presents a simple green synthesis approach for Ag NPs using HPC, achieving superior mechanical performance and stable MMT dispersion in aqueous solutions.


Assuntos
Bentonita , Celulose , Hidrogéis , Líquidos Iônicos , Nanopartículas Metálicas , Prata , Poluentes Químicos da Água , Celulose/química , Celulose/análogos & derivados , Líquidos Iônicos/química , Catálise , Bentonita/química , Hidrogéis/química , Poluentes Químicos da Água/química , Prata/química , Nanopartículas Metálicas/química , Ânions/química , Nitrofenóis/química , Química Verde , Purificação da Água/métodos
8.
Int J Biol Macromol ; 273(Pt 2): 132769, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-38823745

RESUMO

Paper-based test film material is widely used in a variety of test instruments for different applications. The enzyme activity test paper sheet is one of the most popularly used test papers. Here we present a novel fabrication of paper-based enzyme activity test paper without cationic resin added in. The chemical pulping fibers were first beaten to different degrees (from 14.6 to 41.5°SR) with a PFI beater. After that, the fibers were modified with a cationic agent (3-chloro-2-hydroxypropyl trimethyl ammonium chloride) under the system of alkali and water solution. Finally, the test papers were made with the modified fiber by a regular paper former in lab. The results showed that beating is beneficial for the improvement of the cationization reaction which is indicated by the Zeta potential, FTIR and EDS. The main mechanisms involved are the destruction of crystalline zone, increase of free hydroxyl group and defibrillation. This hypothesis was supported by the SEM, XRD and fiber analyzer. Beating under the optimized condition, the wet strength and liquid absorbability of test paper can meet the application requirement, and the test results of enzyme activity are quite close to those of commercial test papers.


Assuntos
Ânions , Papel , Adsorção , Ânions/química , Madeira/química , Cátions/química
9.
Mikrochim Acta ; 191(7): 401, 2024 06 17.
Artigo em Inglês | MEDLINE | ID: mdl-38884887

RESUMO

The simultaneous discrimination and detection of multiple anions in an aqueous solution has been a major challenge due to their structural similarity and low charge radii. In this study, we have constructed a supramolecular fluorescence sensor array based on three host-guest complexes to distinguish five anions (F-, Cl-, Br-, I-, and ClO-) in an aqueous solution using anionic-induced fluorescence quenching combined with linear discriminant analysis. Due to the different affinities of the three host-guest complexes for each anion the anion quenching efficiency for each host-guest complex was likewise different, and the five anions were well recognized. The fluorescence sensor array not only distinguished anions at different concentrations (0.5, 10, and 50 µM) with 100% accuracy but also showed good linearity within a certain concentration range. The limit of detection (LOD) was < 0.5 µM. Our interference study showed that the developed sensor array had good anti-interference ability. The practicability of the developed sensor array was also verified by the identification and differentiation of toothpaste brands with different fluoride content and the prediction of the iodine concentration in urine combined with machine learning.


Assuntos
Ânions , Iodo , Limite de Detecção , Aprendizado de Máquina , Espectrometria de Fluorescência , Ânions/urina , Ânions/química , Iodo/urina , Iodo/química , Espectrometria de Fluorescência/métodos , Cremes Dentais/química , Corantes Fluorescentes/química , Fluoretos/química , Fluoretos/urina , Análise Discriminante
10.
Int J Biol Macromol ; 272(Pt 1): 132842, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38830490

RESUMO

Eco-friendly and renewable sodium alginate, as a potential alternative to fossil resources, has attracted considerable attention in wastewater treatment field. Herein, we develop a SA/PEI/PEG (sodium alginate/polyethyleneimine/polyethylene glycol diglycidyl ether) adsorbent in which SA was functionalized by PEI/PEG via a facile but effective strategy of one-pot gelation of aqueous SA/PEI/PEG solution. Systematic investigations were accomplished to explore the effects of adsorbent factors on the adsorption performances of the adsorbent towards the anionic dyes CR (congo red), AB-10B (amido black-10B), and AB-25 (acid blue-25). Strikingly, the SA/PEI/PEG exhibited exceptional adsorption performance to CR (2782 mg g-1, 90.6 %), AB-10B (1369 mg g-1, 90.9 %) and AB-25 (4221 mg g-1, 92.6 %) at 30 °C, pH = 3, 200 r min-1 and oscillated 24 h, and demonstrating exceptional reusability after six cycles of adsorption-desorption cycles. Furthermore, the three kinetic, four isothermic and one thermodynamic models were used to investigate the adsorption behaviors of the adsorbent towards these dyes. The possible adsorption mechanism is suggested: Hydrogen bond interactions and electrostatic attractions between SA/PEI/PEG and the dyes primarily contribute to exceptional adsorption capacity. The SA/PEI/PEG adsorbent endowed with easy fabrication, extraordinary adsorption capacity and excellent reusability promises potential application prospects in wastewater purification industry.


Assuntos
Alginatos , Corantes , Poluentes Químicos da Água , Purificação da Água , Alginatos/química , Adsorção , Corantes/química , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Purificação da Água/métodos , Ânions/química , Cinética , Polietilenoglicóis/química , Concentração de Íons de Hidrogênio , Polietilenoimina/química , Termodinâmica
11.
J Enzyme Inhib Med Chem ; 39(1): 2346523, 2024 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-38847581

RESUMO

Toxoplasmosis, induced by the intracellular parasite Toxoplasma gondii, holds considerable implications for global health. While treatment options primarily focusing on folate pathway enzymes have notable limitations, current research endeavours concentrate on pinpointing specific metabolic pathways vital for parasite survival. Carbonic anhydrases (CAs, EC 4.2.1.1) have emerged as potential drug targets due to their role in fundamental reactions critical for various protozoan metabolic processes. Within T. gondii, the Carbonic Anhydrase-Related Protein (TgCA_RP) plays a pivotal role in rhoptry biogenesis. Notably, α-CA (TcCA) from another protozoan, Trypanosoma cruzi, exhibited considerable susceptibility to classical CA inhibitors (CAIs) such as anions, sulphonamides, thiols, and hydroxamates. Here, the recombinant DNA technology was employed to synthesise and clone the identified gene in the T. gondii genome, which encodes an α-CA protein (Tg_CA), with the purpose of heterologously overexpressing its corresponding protein. Tg_CA kinetic constants were determined, and its inhibition patterns explored with inorganic metal-complexing compounds, which are relevant for rational compound design. The significance of this study lies in the potential development of innovative therapeutic strategies that disrupt the vital metabolic pathways crucial for T. gondii survival and virulence. This research may lead to the development of targeted treatments, offering new approaches to manage toxoplasmosis.


Assuntos
Inibidores da Anidrase Carbônica , Anidrases Carbônicas , Clonagem Molecular , Toxoplasma , Toxoplasma/enzimologia , Anidrases Carbônicas/metabolismo , Anidrases Carbônicas/genética , Cinética , Inibidores da Anidrase Carbônica/farmacologia , Inibidores da Anidrase Carbônica/química , Inibidores da Anidrase Carbônica/síntese química , Relação Estrutura-Atividade , Relação Dose-Resposta a Droga , Estrutura Molecular , Ânions/química , Ânions/farmacologia , Ânions/metabolismo
12.
Int J Biol Macromol ; 271(Pt 1): 132595, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38821803

RESUMO

Biomass chitosan has garnered considerable interest for alkaline anion exchange membranes (AEMs) due to its eco-friendly and sustainable characteristics, low reactant permeability and easily modifiable nature, but it still faces the trade-off between high hydroxide conductivity and sufficient mechanical properties. Herein, a novel functionalized attapulgite clay (f-ATP) with a unique ionic "chain-ball" surface structure was prepared and incorporated with quaternized chitosan (QCS)/polyvinyl alcohol (PVA) matrix to fabricate high-performance composite AEMs. Due to the strengthened interfacial bonding between f-ATP nanofillers and the QCS/PVA matrix, composite membranes are synergistically reinforced and toughened, achieving peak tensile strength and elongation at break of 24.62 MPa and 33.8 %. Meanwhile, abundant ion pairs on f-ATP surface facilitate ion transport in the composite AEMs, with the maximum OH- conductivity of 46 mS cm-1 at 80 °C and the highest residual IEC of 83 % after alkaline treatment for 120 h. Moreover, the assembled alkaline direct methanol fuel cell exhibits a remarkable power density of 49.3 mW cm-2 at 80 °C. This work provides a new strategy for fabricating high-performance anion exchange membranes.


Assuntos
Quitosana , Argila , Compostos de Magnésio , Membranas Artificiais , Álcool de Polivinil , Compostos de Silício , Quitosana/química , Álcool de Polivinil/química , Compostos de Magnésio/química , Compostos de Silício/química , Argila/química , Ânions/química , Troca Iônica , Resistência à Tração , Propriedades de Superfície
13.
Int J Biol Macromol ; 271(Pt 1): 132368, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38761912

RESUMO

The structural stability and therapeutic activity of Stem Bromelain (BM) have been explored by unravelling the interaction of stem BM in presence of two different types of anionic surfactants namely, bile salts, NaC and NaDC and the conventional anionic surfactants, SDDS and SDBS, below, at and above the critical micelle concentration (cmc) in aqueous phosphate buffer of pH 7. Different physicochemical parameters like, surface excess (Γcmc), minimum area of surfactants at air water interface (Amin) etc. are calculated from tensiometry both in absence and presence of BM. Several inflection points (C1, C2 and C3) have been found in tensiometry profile of surfactants in presence of BM due to the conformational change of BM assisted by surfactants. Similar observation also found in isothermal titration calorimetry (ITC) profiles where the enthalpy of micellization (ΔH0obs) of surfactants in absence and presence of BM have calculated. Further, steady state absorption and fluorescence spectra monitoring the tryptophan (Trp) emission of free BM and in presence of all the surfactants at three different temperatures (288.15 K, 298.15 K, and 308.15 K) reveal the nature of fluorescence quenching of BM in presence of bile salts/surfactants. Time resolved fluorescence studies at room temperature also support to determine the several quenching parameters. The binding constant (Kb) of BM with all the surfactants and free energy of binding (∆G0 of bile salts/surfactants with BM at different temperatures have been calculated exploiting steady state fluorescence technique. It is observed that, the binding of NaC with BM is greater as compared to other surfactants while Stern-Volmer quenching constant (KSV) is found greater in presence of SDBS as compared with others which supports the surface tension and ITC data with the fact that surface activity of surfactant(s) is decreasing with the binding of the surfactants at the core or binding pocket of BM. Circular Dichroism (CD) study shows the stability of secondary structure of BM in presence of NaC and NaDC below C3, while BM lost its structural stability even at very low surfactant concentration of SDDS and SDBS which also supports the more involvement of bile salts in binding rather than surfactants. The molecular docking studies have also been substantiated for better understanding the several experimental investigations interaction of BM with the bile salts/surfactants.


Assuntos
Bromelaínas , Micelas , Simulação de Acoplamento Molecular , Tensoativos , Termodinâmica , Bromelaínas/química , Bromelaínas/metabolismo , Tensoativos/química , Concentração de Íons de Hidrogênio , Ânions/química , Espectrometria de Fluorescência , Soluções Tampão
14.
Int J Biol Macromol ; 270(Pt 1): 132056, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38704070

RESUMO

Since the potential carcinogenic, toxic and non-degradable dyes trigger serious environmental contamination by improper treatment, developing novel adsorbents remains a major challenge. A novel high efficiency and biopolymer-based environmental-friendly adsorbent, chitosan­sodium tripolyphosphate-melamine sponge (CTS-STPP-MS) composite, was prepared for Orange II removing with chitosan as raw material, sodium tripolyphosphate as cross-linking agent. The composite was carefully characterized by SEM, EDS, FT-IR and XPS. The influence of crosslinking conditions, dosage, pH, initial concentration, contacting time and temperature on adsorption were tested through batch adsorption experiments. CTS-STPP-MS adsorption process was exothermic, spontaneous and agreed with Sips isotherm model accompanying the maximum adsorption capacity as 948 mg∙g-1 (pH = 3). Notably, the adsorption performance was outstanding for high concentration solutions, with a removal rate of 97 % in up to 2000 mg∙L-1 OII solution (100 mg sorbent dosage, 50 mL OII solution, pH = 3, 289.15 K). In addition, the adsorption efficiency yet remained 97.85 % after 5 repeated adsorption-desorption cycles. The driving force of adsorption was attributed to electrostatic attraction and hydrogen bonds which was proved by adsorption results coupled with XPS. Owing to the excellent properties of high-effective, environmental-friendly, easy to separate and regenerable, CTS-STPP-MS composite turned out to be a promising adsorbent in contamination treatment.


Assuntos
Compostos Azo , Quitosana , Triazinas , Poluentes Químicos da Água , Quitosana/química , Quitosana/análogos & derivados , Adsorção , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Triazinas/química , Compostos Azo/química , Compostos Azo/isolamento & purificação , Concentração de Íons de Hidrogênio , Purificação da Água/métodos , Benzenossulfonatos/química , Cinética , Polifosfatos/química , Ânions/química , Temperatura , Corantes/química , Corantes/isolamento & purificação
15.
Dalton Trans ; 53(20): 8633-8641, 2024 May 21.
Artigo em Inglês | MEDLINE | ID: mdl-38695060

RESUMO

Poor cellular permeability greatly hampers the utilization of anionic Ir(III) complexes, though efficiently emissive and remarkably stable, in cell-based diagnosis. To overcome this barrier, we present the development of an alkaline phosphatase (ALP)-responsive, anionic, and aggregation-induced emission (AIE)-active Ir(III) complex (Ir1) for specific recognition of osteosarcoma cells. Containing phosphate moieties, Ir1 exhibits a net -1 charge, enabling charge repulsion from the cell membrane and resulting in low cellular uptake and good biocompatibility in normal osteoblast cells. Upon ALP-mediated hydrolysis of phosphate groups, the resulting dephosphorylated product, Ir2, demonstrates a positive charge and increased lipophilicity, promoting cellular uptake and activating its AIE properties for specific recognition of osteosarcoma cells that express elevated levels of ALP. This study elucidates the role of ALP as an ideal trigger for enhancing the cellular permeability of phosphate ester-containing Ir(III) complexes, thus expanding the potential of anionic Ir(III) complexes for biomedical applications.


Assuntos
Fosfatase Alcalina , Ânions , Complexos de Coordenação , Irídio , Osteossarcoma , Irídio/química , Humanos , Osteossarcoma/patologia , Osteossarcoma/metabolismo , Fosfatase Alcalina/metabolismo , Complexos de Coordenação/química , Complexos de Coordenação/síntese química , Complexos de Coordenação/farmacologia , Ânions/química , Linhagem Celular Tumoral
16.
Chemosphere ; 358: 142215, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38701865

RESUMO

The existence of microplastics (MPs) in water is a significant global concern since they have the potential to pose a threat to human health. Therefore, there is a need to develop a sustainable treatment technology for MPs removal, as the conventional methods are inadequate to address this problem. Coagulation is a typical process in treatment plants that can capture MPs before releasing them into the environment. In this work, the removal behaviors of polyamide (PA), polystyrene (PS), and polyethylene (PE) MPs were systematically investigated through coagulation processes using aluminum sulfate (Al2(SO4)3) and Moringa oleifera (MO) seeds extract. Subsequently, the coagulation performance of Al2(SO4)3 was improved by the separate addition of anionic polyacrylamide (APAM) and naturally derived MO. Results showed that Al2(SO4)3 in combination with APAM had better performance than Al2(SO4)3 or MO alone. In the Al2(SO4)3+APAM system, the removal efficiencies were 93.47%, 81.25%, and 29.48% for PA, PS, and PE MPs, respectively. Furthermore, the effectiveness of the Al2(SO4)3 and MO blended system was approximately similar to the Al2(SO4)3+APAM system. However, the required amount of Al2(SO4)3 was decreased to 50% in the Al2(SO4)3+MO system compared to the optimal dosage in the Al2(SO4)3 system alone. The combination of 40 mg/L of Al2(SO4)3 and 60 mg/L of MO resulted in removal efficiencies of 92.99%, 80.48%, and 28.94% for PA, PS, and PE MPs, respectively. The high efficacy of these enhanced methods was due to the synergic effects of charge neutralization and agglomeration adsorption, which were validated through zeta potential assessments and visual analysis using scanning electron microscopy (SEM) images. In the case of experimental conditions, initial pH had little impact on removal efficiency, while NaCl salinity and stirring speed directly affected MPs removal. Consequently, this research took a step toward finding a green strategy to remove MPs from water systems.


Assuntos
Resinas Acrílicas , Microplásticos , Poluentes Químicos da Água , Purificação da Água , Poluentes Químicos da Água/química , Resinas Acrílicas/química , Purificação da Água/métodos , Moringa oleifera/química , Ânions/química , Adsorção , Poliestirenos/química
17.
Bioorg Chem ; 147: 107421, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38714118

RESUMO

Targeting the homeostasis of anions and iron has emerged as a promising therapeutic approach for the treatment of cancers. However, single-targeted agents often fall short of achieving optimal treatment efficacy. Herein we designed and synthesized a series of novel dual-functional squaramide-hydroxamic acid conjugates that are capable of synergistically modulating the homeostasis of anions and iron. Among them, compound 16 exhibited the most potent antiproliferative activity against a panel of selected cancer cell lines, and strong in vivo anti-tumor efficacy. This compound effectively elevated lysosomal pH through anion transport, and reduced the levels of intracellular iron. Compound 16 could disturb autophagy in A549 cells and trigger robust apoptosis. This compound caused cell cycle arrest at the G1/S phase, altered the mitochondrial function and elevated ROS levels. The present findings clearly demonstrated that synergistic modulation of anion and iron homeostasis has high potentials in the development of promising chemotherapeutic agents with dual action against cancers.


Assuntos
Antineoplásicos , Apoptose , Proliferação de Células , Desenho de Fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Homeostase , Ácidos Hidroxâmicos , Ferro , Humanos , Antineoplásicos/farmacologia , Antineoplásicos/síntese química , Antineoplásicos/química , Ferro/metabolismo , Ferro/química , Proliferação de Células/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Relação Estrutura-Atividade , Ácidos Hidroxâmicos/farmacologia , Ácidos Hidroxâmicos/química , Ácidos Hidroxâmicos/síntese química , Estrutura Molecular , Apoptose/efeitos dos fármacos , Ânions/química , Ânions/farmacologia , Relação Dose-Resposta a Droga , Animais , Linhagem Celular Tumoral , Camundongos , Quinina/análogos & derivados
18.
Int J Mol Sci ; 25(10)2024 May 11.
Artigo em Inglês | MEDLINE | ID: mdl-38791275

RESUMO

A comprehensive thermodynamic and structural study of the complexation affinities of tetra (L1), penta (L2), and hexaphenylalanine (L3) linear peptides towards several inorganic anions in acetonitrile (MeCN) and N,N-dimethylformamide (DMF) was carried out. The influence of the chain length on the complexation thermodynamics and structural changes upon anion binding are particularly addressed here. The complexation processes were characterized by means of spectrofluorimetric, 1H NMR, microcalorimetric, and circular dichroism spectroscopy titrations. The results indicate that all three peptides formed complexes of 1:1 stoichiometry with chloride, bromide, hydrogen sulfate, dihydrogen phosphate (DHP), and nitrate anions in acetonitrile and DMF. In the case of hydrogen sulfate and DHP, anion complexes of higher stoichiometries were observed as well, namely those with 1:2 and 2:1 (peptide:anion) complexes. Anion-induced peptide backbone structural changes were studied by molecular dynamic simulations. The anions interacted with backbone amide protons and one of the N-terminal amine protons through hydrogen bonding. Due to the anion binding, the main chain of the studied peptides changed its conformation from elongated to quasi-cyclic in all 1:1 complexes. The accomplishment of such a conformation is especially important for cyclopeptide synthesis in the head-to-tail macrocyclization step, since it is most suitable for ring closure. In addition, the studied peptides can act as versatile ionophores, facilitating transmembrane anion transport.


Assuntos
Ânions , Termodinâmica , Ânions/química , Peptídeos/química , Peptídeos/metabolismo , Ligação de Hidrogênio , Simulação de Dinâmica Molecular , Acetonitrilas/química , Dimetilformamida/química , Dicroísmo Circular
19.
Int J Biol Macromol ; 269(Pt 2): 131955, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38692542

RESUMO

Dyes pollution is well known for their hazardous impacts on human health and the environment. The removal of dyes from wastewater has become an important issue. In this study, magnetic micrometer-sized particles AL-CTS@MNPs were synthesized from alkaline lignin (AL) and chitosan (CTS) by "one-pot method". The adsorbent presented higher selectivity adsorption effect on anionic dyes than amphoteric and cationic dyes, and even no adsorption effect on cationic methylene blue (MB), which showed that the anionic dyes could be better separated from the other two types of dyes. The adsorption isotherms of the dyes were highly consistent with the Langmuir model, and the maximum adsorption capacity was 329.50 mg/g for methyl orange (MO) and 20.00 mg/g for rhodamine B (RhB). AL-CTS@MNPs showed good adsorption of anionic dyes (MO) in the pH range of 3-9. Meanwhile, the adsorbent AL-CTS@MNPs were also characterized, showing rough surface with specific surface areas of 37.38 m2/g, pore diameter of 95.8 nm and porosity of 17.62 %. The particle sizes were ranged from 800 µm to 1300 µm. The electrostatic attraction and π-π* electron donor-acceptor interactions were the main forces between the adsorbent and anionic dyes. While the electrostatic repulsive force between the adsorbent and the cationic dyes resulted in the non-absorption of MB by AL-CTS@MNPs. Subsequently, the adsorbent maintained a removal rate of >95 % after five adsorption-desorption cycles, demonstrating its excellent stability and recoverability. Ultimately, the prepared AL-CTS@MNPs illuminated good prospect on complex components dyes wastewater treatment.


Assuntos
Quitosana , Corantes , Lignina , Poluentes Químicos da Água , Quitosana/química , Adsorção , Lignina/química , Corantes/química , Corantes/isolamento & purificação , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Ânions/química , Porosidade , Purificação da Água/métodos , Concentração de Íons de Hidrogênio , Azul de Metileno/química , Azul de Metileno/isolamento & purificação , Cinética , Águas Residuárias/química , Nanopartículas de Magnetita/química , Compostos Azo
20.
Int J Biol Macromol ; 269(Pt 1): 131994, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38697431

RESUMO

Nowadays, dye water pollution is becoming increasingly severe. Composite of MXene, ZnS, and chitosan-cellulose material (MX/ZnS/CC) was developed to remove anionic dyes through the synergistic effect of adsorption and photocatalytic degradation. MXene was introduced as the cocatalyst to form Schottky heterostructure with ZnS for improving the separation efficiency of photocarriers and photocatalytic performance. Chitosan-cellulose material mainly served as the dye adsorbent, while also could improve material stability and assist in generation of free radicals for dye degradation. The physics and chemistry properties of MX/ZnS/CC composite were systematically inspected through various characterizations. MX/ZnS/CC composite exhibited good adsorption ability to anionic dyes with adsorption capacity up to 1.29 g/g, and excellent synergistic effects of adsorption and photodegradation with synergistic removal capacity up to 5.63 g/g. MX/ZnS/CC composite performed higher synergistic removal ability and better optical and electrical properties than pure MXene, ZnS, chitosan-cellulose material, and MXene/ZnS. After compounding, the synergistic removal percentage of dyes increased by a maximum of 309 %. MX/ZnS/CC composite mainly adsorbs anionic dyes through electrostatic interactions and catalyzes the generation of •O2-, h+, and •OH to degrade dyes, which has been successfully used to remove anionic dyes from environmental water, achieving a 100 % removal of 50 mg/L dye.


Assuntos
Celulose , Quitosana , Corantes , Poluentes Químicos da Água , Compostos de Zinco , Quitosana/química , Adsorção , Celulose/química , Compostos de Zinco/química , Corantes/química , Corantes/isolamento & purificação , Catálise , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação , Sulfetos/química , Purificação da Água/métodos , Fotólise , Ânions/química
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