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1.
Inorg Chem ; 63(18): 8059-8069, 2024 May 06.
Artículo en Inglés | MEDLINE | ID: mdl-38655576

RESUMEN

Ionic liquids (ILs) have significant potential for eco-friendly extraction of uranium from aqueous solutions, which is critical for nuclear technology, fuel cycle management, and environmental protection. This study examines the impact of the adjustable hydrophobic/hydrophilic properties of ILs on the removal of uranium(VI) (UO22+) from aqueous solutions utilizing both a novel hydrophilic IL (1-butoxyethyl-1-methylmorpholinium butoxyethylphosphite - Mor1-2O4-BOEP) and 1-heptyl-1-methylmorpholinium heptylphosphite (Mor1-7-HP) as an example of a hydrophobic IL with a similar structure. The transfer mechanism of uranyl ions from water to organic or solid phases closely depends on the physicochemical properties of ILs, especially their hydrophobicity. The hydrophobic Mor1-7-HP extracts uranyl via neutral complex formation as UO2(NO3)2-(Mor1-7-HP)2. Conversely, hydrophilic Mor1-2O4-BOEP induced selective precipitation as UO2(NO3)-(BOEP), transferring uranyl to the solid phase. Optimization of the working parameters, in terms of acidity of the aqueous solution and amount of ILs used, allowed the extraction of over 98% of U(VI). The stoichiometry of the organic complex and the precipitate was determined using physicochemical techniques. These tunable H-phosphonate-based ILs have advantages over traditional solvent extraction and conventional ILs, allowing easier handling, improved selectivity, and lower environmental impact. This work advances uranium separation techniques with applications in hydrometallurgy, particularly in the treatment of wastewater and radioactive waste for sustainable uranium recovery.

2.
Molecules ; 28(6)2023 Mar 07.
Artículo en Inglés | MEDLINE | ID: mdl-36985391

RESUMEN

This work aimed to evaluate the biological activities of 20 flavones (M1 to M20) and discuss their structure-activity relationships. In vitro assays were established to assess their numerous biological activities (anti-α-amylase, anti-acetylcholinesterase, anti-xanthine oxidase, anti-superoxide dismutase, and anticancer cell lines (HCT-116, MCF7, OVCAR-3, IGROV-1, and SKOV-3 cells lines)). An in silico docking study was also established in order to find the relationship between the chemical structure and the biological activities. In vitro tests revealed that M5 and M13 were the most active in terms of anti-α-amylase activity (IC50 = 1.2 and 1.4 µM, respectively). M17 was an inhibitor of xanthine oxidase (XOD) and performed better than the reference (allopurinol), at IC50 = 0.9 µM. M7 presented interesting anti-inflammatory (IC50 = 38.5 µM), anti-supriode dismutase (anti-SOD) (IC50 = 31.5 µM), and anti-acetylcholinesterase (IC50 = 10.2 µM) activities. Those abilities were in concordance with its high scavenging activity in antioxidant ABTS and DPPH assays, at IC50 = 6.3 and 5.2 µM, respectively. Selectivity was detected regarding cytotoxic activity for those flavones. M1 (IC50 = 35.9 µM) was a specific inhibitor to the MCF7 cancer cell lines. M3 (IC50 = 44.7 µM) and M15 (IC50 = 45.6 µM) were particularly potent for the OVCAR-3 cell line. M14 (IC50 = 4.6 µM) contributed more clearly to inhibiting the colon cancer cell line (HCT116). M7 (IC50 = 15.6 µM) was especially active against the ovarian SKOV human cancer cell line. The results of the biological activities were supported by means of in silico molecular docking calculations. This investigation analyzed the contribution of the structure-activity of natural flavones in terms of their biological properties, which is important for their future application against diseases.


Asunto(s)
Antineoplásicos , Flavonas , Neoplasias Ováricas , Humanos , Femenino , Flavonas/farmacología , Simulación del Acoplamiento Molecular , Apoptosis , Línea Celular Tumoral , Antineoplásicos/farmacología , Antineoplásicos/química , Relación Estructura-Actividad , Superóxido Dismutasa/metabolismo , Xantina Oxidasa , Amilasas/metabolismo , Estructura Molecular , Relación Dosis-Respuesta a Droga , Ensayos de Selección de Medicamentos Antitumorales , Proliferación Celular
3.
Bioorg Chem ; 114: 105073, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34153810

RESUMEN

Synthetic routes to a series of benzoylarylbenzimidazol 3a-h have been derived from 3,4-diaminobenzophenone and an appropriate arylaldehyde in the presence of ammonium chloride or a mixture of ammonium chloride and sodium metabisulfite as catalyst. The antioxidant activity of targeted compounds 3a-h has been measured by four different methods and the overall antioxidant evaluation of the compounds indicated the significant MCA, FRAP, and (DPPH-SA) of the compounds except for the compound 3h. In vitro antidiabetic assay of α-amylase and α-glucosidase suggest a good to excellent activity for most tested compounds. The target benzimidazole 3f containing hydroxyl motif at para-position of phenyl revealed an important activity inhibitor against α- amylase (IC50 = 12.09 ± 0.38 µM) and α-glucosidase (IC50 = 11.02 ± 0.04 µM) comparable to the reference drug acarbose. The results of the anti hyperglycemic activity were supported by means of in silico molecular docking calculations showing strong binding affinity of compounds 3a-h with human pancreatic α-amylase (HPA) and human lysosomal acid-α-glucosidase (HLAG) active sites that confirm a good to excellent activity for most of tested compounds.


Asunto(s)
Antioxidantes/farmacología , Bencimidazoles/farmacología , Inhibidores de Glicósido Hidrolasas/farmacología , alfa-Amilasas/antagonistas & inhibidores , alfa-Glucosidasas/metabolismo , Antioxidantes/síntesis química , Antioxidantes/química , Bencimidazoles/síntesis química , Bencimidazoles/química , Compuestos de Bifenilo/antagonistas & inhibidores , Relación Dosis-Respuesta a Droga , Inhibidores de Glicósido Hidrolasas/síntesis química , Inhibidores de Glicósido Hidrolasas/química , Humanos , Estructura Molecular , Picratos/antagonistas & inhibidores , Relación Estructura-Actividad , alfa-Amilasas/metabolismo
4.
Bioorg Chem ; 104: 104270, 2020 11.
Artículo en Inglés | MEDLINE | ID: mdl-32947132

RESUMEN

In an effort to explore a new class of antidiabetic inhibitors, a new series of isoxazolidine and C-alkyl imine oxide derivatives scaffolds were designed, synthesized and fully characterized. The newly synthesized analogues were evaluated for their human pancreatic α-amylase (HPA) and human lysosomal acid-α-glucosidase (HLAG) inhibitory activities and have shown a higher potency than acarbose. The compounds 7b (23.1 ± 1.1 µM) and 7a (36.3 ± 1.6 µM) were identified as the potent HPA and HLAG inhibitors with inhibitory effect up to 9 and 21-fold higher than acarbose, respectively. Antihyperglycemic activity results were supported by molecular docking approach of the most potent compounds 7b and 7a showing stronger interactions with the active site of HPA and HLAG as well as by in silico absorption, distribution, metabolism, excretion and toxicity (ADMET) profile suggesting their satisfactory oral druglikeness without toxic effect. Therefore, it can be concluded that both 7b and 7a can be used as effective lead molecules for the development of HPA and HLAG inhibitors for the management of T2DM.


Asunto(s)
Diseño de Fármacos , Inhibidores de Glicósido Hidrolasas/farmacología , Hipoglucemiantes/farmacología , Iminas/farmacología , Isoxazoles/farmacología , Óxidos/farmacología , Relación Dosis-Respuesta a Droga , Inhibidores de Glicósido Hidrolasas/síntesis química , Inhibidores de Glicósido Hidrolasas/química , Humanos , Hipoglucemiantes/síntesis química , Hipoglucemiantes/química , Iminas/síntesis química , Iminas/química , Isoxazoles/síntesis química , Isoxazoles/química , Lisosomas/enzimología , Simulación del Acoplamiento Molecular , Estructura Molecular , Óxidos/síntesis química , Óxidos/química , Páncreas/enzimología , Relación Estructura-Actividad , alfa-Amilasas/antagonistas & inhibidores , alfa-Amilasas/metabolismo , alfa-Glucosidasas/metabolismo
5.
Bioorg Chem ; 98: 103713, 2020 05.
Artículo en Inglés | MEDLINE | ID: mdl-32151966

RESUMEN

A series of novel isoxazolidines based on benzaldehyde derivatives have been synthesized from the cycloaddition of chiral menthone-based nitrone and allyl phenyl ethers. All synthetic compounds were assessed for their in vitro PPA, HPA and HLAG inhibitory activity. The results revealed that all targets exhibited better inhibitory effect against PPA (12.3 ± 0.4 < IC50 < 38.2 ± 0.9 µM), HPA (10.1 ± 0.4 < IC50 < 26.8 ± 0.2 µM) and HLAG (65.4 ± 1.2 < IC50 < 274.8 ± 1.1 µM) when compared with the reference inhibitor, acarbose (IC50 = 284.6 ± 0.3 µM for PPA, 296.6 ± 0.8 µM for HPA, 780.4 ± 0.3 µM for HLAG) with the highest PPA inhibitory activity was ascribed to compound 3g against both PPA and HPA, and 3b against HLAG enzymes, respectively. Structural activity relationships (SARs) were also established for all synthesized compounds and the interaction modes of the most potent inhibitors (3g for PPA and HPA, 3b for HLAG) and the active site with residues of three enzymes were confirmed through molecular docking studies. Furthermore, a combination of molecular docking analysis with the in vitro activities can help to improve prediction success and encourages the uses of some of these molecules as potential alternatives toward the modulation of T2D.


Asunto(s)
Inhibidores de Glicósido Hidrolasas/farmacología , Isoxazoles/farmacología , alfa-Amilasas/antagonistas & inhibidores , alfa-Glucosidasas/metabolismo , Animales , Relación Dosis-Respuesta a Droga , Inhibidores de Glicósido Hidrolasas/síntesis química , Inhibidores de Glicósido Hidrolasas/química , Humanos , Isoxazoles/síntesis química , Isoxazoles/química , Simulación del Acoplamiento Molecular , Estructura Molecular , Páncreas/enzimología , Relación Estructura-Actividad , Porcinos , alfa-Amilasas/metabolismo
6.
J Phys Chem A ; 119(23): 6148-54, 2015 Jun 11.
Artículo en Inglés | MEDLINE | ID: mdl-25866992

RESUMEN

We report on the single photoionization of jet-cooled benzophenone using a tunable source of VUV synchrotron radiation coupled with a photoion/photoelectron coincidence acquisition device. The assignment and the interpretation of the spectra are based on a characterization by ab initio and density functional theory calculations of the geometry and of the electronic states of the cation. The absence of structures in the slow photoelectron spectrum is explained by a congestion of the spectrum due to the dense vibrational progressions of the very low frequency torsional mode in the cation either in pure form or in combination bands. Also a high density of electronic states has been found in the cation. Presently, we estimate the experimental adiabatic and vertical ionization energy of benzophenone at 8.80 ± 0.01 and 8.878 ± 0.005 eV, respectively. The ionization energy as well as the energies of the excited states are compared to the calculated ones.

7.
Heliyon ; 10(4): e26341, 2024 Feb 29.
Artículo en Inglés | MEDLINE | ID: mdl-38404822

RESUMEN

A novel isoxazolidine derivative (ISoXD) dye was successfully synthesized and comprehensively characterized. In this study, we conducted a thorough examination of its various properties, including optical characteristics, interactions with DNA and ß-cyclodextrin (ß-CD), molecular docking, molecular dynamic simulation, and density functional theory (DFT) calculations. Our investigation encompassed a systematic analysis of the absorption and emission spectra of ISoXD in diverse solvents. The observed variations in the spectroscopic data were attributed to the specific solvent's capacity to engage in hydrogen bonding interactions. Remarkably, the most pronounced intensities were observed in glycol, which can establish many hydrogen bonds with ISoXD. Furthermore, our study revealed a significant distinction in the fluorescence behavior of ISoXD when subjected to different solvents, particularly between CHCl3 and CDCl3. Moreover, we explored the fluorescence intensity of the ISoXD complex in the presence of various metals, both in ethanol and water. The ISoXD complex exhibited a substantial increase of fluorescence upon interaction with different metal ions. The utilization of DFT calculations allowed us to propose an intramolecular charge transfer (ICT) mechanism as a plausible explanation for this quenching phenomenon. The interaction of ISoXD with DNA and ß-CD was studied using absorption spectra. The binding constant (K) and the standard Gibbs free energy change (ΔGo) for the interaction between DNA and ß-CD with ISoXD were determined. In docking study, ISoXD exhibited significant docking scores (-6.511) and MM-GBSA binding free energies (-66.27 kcal/mol) within the PARP-1 binding cavity. Its binding pattern closely resembles to the co-crystal ligand veliparib, and during a 100ns MD simulation, ISoXD displayed strong stability and formed robust hydrogen bonds with key amino acids. These findings suggest ISoXD's potential as a PARP-1 inhibitor for further investigation in therapeutic development.

8.
RSC Adv ; 13(28): 19607-19616, 2023 Jun 22.
Artículo en Inglés | MEDLINE | ID: mdl-37388147

RESUMEN

Graphene and other 2D materials have gained significant attention in the development of gas sensors. In this study, we employed Density Functional Theory (DFT) to investigate the adsorption properties of diazomethanes (1a-1g) with various functional groups (R = OH (a), OMe (b), OEt (c), OPr (d), CF3 (e), Ph (f)) on pristine graphene. Furthermore, we explored the adsorption behavior of activated carbenes (2a-2g) generated from the decomposition of diazomethanes on graphene, as well as the functionalized graphene derivatives (3a-3g) resulting from [2 + 1] cycloaddition reactions between (2a-2g) and graphene. The interaction between these functionalized derivatives (3a-3g) and toxic gases was also investigated. Our results revealed that carbenes exhibited a stronger affinity for graphene compared to diazomethanes. The adsorption energy of esters (3b, 3c, and 3d) on graphene decreased relative to compound 3a, while 3e exhibited increased adsorption energy due to the electron-withdrawing effect of fluorine atoms. Additionally, the adsorption energy of phenyl and nitrophenyl groups (3f and 3g) decreased due to their π-stacking interaction with graphene. Importantly, all functionalized derivatives (3a-3g) demonstrated favorable interactions with gases. Notably, the derivative 3a, acting as a hydrogen bonding donor, exhibited superior performance. Furthermore, modified graphene derivatives exhibited the highest adsorption energy with NO2 gas, highlighting their potential for selective NO2 sensing applications. These findings contribute to the understanding of gas-sensing mechanisms and the design of novel graphene-based sensor platforms.

10.
Saudi J Biol Sci ; 30(3): 103598, 2023 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-36874197

RESUMEN

The condensation of (1H-benzimidazole-2-yl) methanamine, with 2-hydroxy naphthaldehyde lead to Schiff base ligand (H2L) (1). This was later reacted with metal salts (ZnCl2, CrCl3·6H2O, and MnCl2·4H2O) to afford the corresponding metal complexes. Biological activity findings indicate that the metal complexes have promising activity against Escherichia coli and Bacillus subtilis and modest activity against Aspergillus niger. The in vitro anticancer activities of Zn (II), Cr (III), and Mn (II) complexes were investigated and the best results were observed with Mn (II) complex as the most potent cytotoxic agent toward human cell lines colorectal adenocarcinoma HCT 116, hepatocellular carcinoma HepG2 and breast adenocarcinoma MCF-7 with 0.7, 1.1 and 6.7 µg of inhibitory concentration IC50 values respectively. Consequently, the Mn (II) complex and ligand were docked inside the energetic site of ERK2 and exhibited favorable energy for binding. The investigation of biological tests towards mosquito larvae indicates that Cr (III) and Mn (II) complexes manifest strong toxicity against Aedes aegypti larvae with 3.458 and 4.764 ppm values of lethal concentration LC50, respectively.

11.
Biosensors (Basel) ; 13(3)2023 Mar 08.
Artículo en Inglés | MEDLINE | ID: mdl-36979571

RESUMEN

Throughout this research, a unique optical sensor for detecting one of the most dangerous heavy metal ions, Cu(II), was designed and developed. The (4-mercaptophenyl) iminomethylphenyl naphthalenyl carbamate (MNC) sensor probe was effectively prepared. The Schiff base of the sensor shows a "turn-off" state with excellent sensitivity to Cu(II) ions. This innovative fluorescent chemosensor possesses distinctive optical features with a substantial Stocks shift (about 114 nm). In addition, MNC has remarkable selectivity for Cu(II) relative to other cations. Density functional theory (DFT) and the time-dependent DFT (TDDFT) theoretical calculations were performed to examine Cu(II) chelation structures and associated electronic properties in solution, and the results indicate that the luminescence quenching in this complex is due to ICT. Chelation-quenched fluorescence is responsible for the internal charge transfer (ICT)-based selectivity of the MNC sensing molecule for Cu(II) ions. In a 1:9 (v/v) DMSO-HEPES buffer (20 mM, pH = 7.4) solution, Fluorescence and UV-Vis absorption of the MNC probe and Cu(II) ions were investigated. By utilizing a solution containing several metal ions, the interference of other metal ions was studied. This MNC molecule has outstanding selectivity and sensitivity, as well as a low LOD (1.45 nM). Consequently, these distinctive properties enable it to find the copper metal ions across an actual narrow dynamic range (0-1.2 M Cu(II)). The reversibility of the sensor was obtained by employing an EDTA as a powerful chelating agent.


Asunto(s)
Colorantes Fluorescentes , Bases de Schiff , Espectrometría de Fluorescencia , Bases de Schiff/química , Colorantes Fluorescentes/química , Cobre/química , Metales , Iones
12.
Pharmaceutics ; 15(2)2023 Jan 30.
Artículo en Inglés | MEDLINE | ID: mdl-36839780

RESUMEN

A novel series of benzimidazole ureas 3a-h were elaborated using 2-(1H-benzoimidazol-2-yl) aniline 1 and the appropriate isocyanates 2a-h. The antioxidant and possible antidiabetic activities of the target benzimidazole-ureas 3a-h were evaluated. Almost all compounds 3a-h displayed strong to moderate antioxidant activities. When tested using the three antioxidant techniques, TAC, FRAP, and MCA, compounds 3b and 3c exhibited marked activity. The most active antioxidant compound in this family was compound 3g, which had excellent activity using four different methods: TAC, FRAP, DPPH-SA, and MCA. In vitro antidiabetic assays against α-amylase and α-glucosidase enzymes revealed that the majority of the compounds tested had good to moderate activity. The most favorable results were obtained with compounds 3c, 3e, and 3g, and analysis revealed that compounds 3c (IC50 = 18.65 ± 0.23 µM), 3e (IC50 = 20.7 ± 0.06 µM), and 3g (IC50 = 22.33 ± 0.12 µM) had good α-amylase inhibitory potential comparable to standard acarbose (IC50 = 14.21 ± 0.06 µM). Furthermore, the inhibitory effect of 3c (IC50 = 17.47 ± 0.03 µM), 3e (IC50 = 21.97 ± 0.19 µM), and 3g (IC50 = 23.01 ± 0.12 µM) on α-glucosidase was also comparable to acarbose (IC50 = 15.41 ± 0.32 µM). According to in silico molecular docking studies, compounds 3a-h had considerable affinity for the active sites of human lysosomal acid α-glucosidase (HLAG) and pancreatic α-amylase (HPA), indicating that the majority of the examined compounds had potential anti-hyperglycemic action.

13.
Antibiotics (Basel) ; 12(3)2023 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-36978368

RESUMEN

The current study aimed to investigate the phytochemical contents and antioxidant, antimicrobial, and antibiofilm activities of four halophytic plants, namely, Euphorbia chamaesyce, Bassia arabica, Fagonia mollis, and Haloxylon salicornicum, native to central Saudi Arabia. The alcoholic extract of E. chamaesyce was found to be the most potent in various bioactivities-based evaluations and rich in polyphenols and flavonoid secondary metabolites, with 68.0 mg/g and 39.23 mg/g gallic acid and quercetin equivalents, respectively. Among all plants' extracts, the alcoholic extract of E. chamaesyce had the highest DPPH scavenging and metal chelating antioxidant activities at 74.15 Trolox equivalents and 16.28 EDTA equivalents, respectively. The highest antimicrobial activity of E. chamaesyce extract was found to be against Shigella flexneri, with a mean zone of inhibition diameter of 18.1 ± 0.2 mm, whereas the minimum inhibitory concentration, minimum biocidal concentration, minimum biofilm inhibitory concentration, and minimum biofilm eradication concentration values were 12.5, 25, 25, and 50 mg/mL, respectively. The LC-ESI-MS/MS analysis of the E. chamaesyce extract showed the presence of six flavonoids and ten phenolic constituents. The in silico binding of the E. chamaesyce extract's constituents to Staphylococcus aureus tyrosyl-tRNA synthetase enzyme displayed -6.2 to -10.1 kcal/mol binding energy values, suggesting that these constituents can contribute to the antimicrobial properties of the plant extract, making it an essential medicinal ingredient. In conclusion, these results warrant further investigation to standardize the antimicrobial profiles of these plant extracts.

14.
ACS Omega ; 7(3): 2661-2670, 2022 Jan 25.
Artículo en Inglés | MEDLINE | ID: mdl-35097264

RESUMEN

Hydroxymethylsilanetriol undergoes condensation reactions to form new structures with an organic part in the formed bridges. As a first step to explore the formation of these bridges, we studied the corresponding mechanisms using simple models and theoretical methods. Three mechanisms were studied for the formation of dimers of hydroxymethylsilanetriol with bridges: Si-O-C-Si, Si-O-Si, and Si-C-O-C-Si. Energies are calculated using M06/6-311+G(d,p) single-point calculations on B3LYP-optimized geometries in solution and including B3LYP thermodynamic corrections. The first mechanism for the formation of the Si-O-C-Si bridge consists of one step. The second mechanism for the formation of the Si-O-Si bridge consists of two steps. The barrier for the last mechanism for the formation of the Si-C-O-C-Si bridge is too high and cannot occur at room temperature. The energy barriers are 31.8, 27.6, and 65.9 kcal mol-1 for the first, second, and third mechanisms, respectively. When adding one explicit water molecule, these energies are 25.9, 22.9, and 80.3 kcal mol-1, respectively. The first and second mechanisms can occur at room temperature, which is in agreement with the experimental results.

15.
Biosensors (Basel) ; 12(11)2022 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-36421146

RESUMEN

We developed a new optical sensor for tracing Hg(II) ions. The detection affinity examines within a concentration range of 0-4.0 µM Hg(II). The sensor film is based on Methyl 2-hydroxy-3-(((2S,2'R,3a'S,5R)-2-isopropyl-5,5'-dimethyl-4'-oxotetrahydro-2'H-spiro[cy-clohexane-1,6'-im-idazo[1,5-b]isoxazol]-2'-yl)methyl)-5-methylbenzoate (IXZD). The novel synthesized compound could be utilized as an optical turn-on chemosensor for pH. The emission intensity is highly enhanced for the deprotonated form concerning the protonated form. IXZD probe has a characteristic fluorescence peak at 481 nm under excitation of 351 nm with large Stocks shift of approximately 130 nm. In addition, the binding process of IXZD:Hg(II) presents a 1:1 molar ratio which is proved by the large quench of the 481 nm emission peak of IXZD and the growth of a new emission peak at 399 nm (blue shift). The binding configurations with one Hg(II) cation and its electronic characteristics were investigated by applying the Density Functional Theory (DFT) and the time-dependent DFT (TDDFT) calculations. Density functional theory (DFT) and the time-dependent DFT (TDDFT) theoretical results were provided to examine Hg(II)-IXZD structures and their electronic properties in solution. The developed chemical sensor was offered based on the intramolecular charge transfer (ICT) mechanism. The sensor film has a significantly low limit of detection (LOD) for Hg(II) of 0.025 µM in pH 7.4, with a relative standard deviation RSDr (1%, n = 3). Lastly, the IXZD shows effective binding affinity to mercury ions, and the binding constant Kb was estimated to be 5.80 × 105 M-1. Hence, this developed optical sensor film has a significant efficiency for tracing mercury ions based on IXZD molecule-doped sensor film.


Asunto(s)
Mercurio , Mercurio/química , Iones , Límite de Detección , Espectrometría de Fluorescencia , Concentración de Iones de Hidrógeno
16.
Environ Monit Assess ; 172(1-4): 301-17, 2011 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-20174865

RESUMEN

The Mytilos project was carried during the last 3 years (2004-2006) in order to evaluate the level of chemical contamination along the coasts of the western basin of the Mediterranean Sea. Active mussel watch consisted of caged (12 weeks) Mytilus galloprovincialis at 123 stations along the Mediterranean coasts of Spain, France, Italy, North Tunisia, Algeria and Morocco. Results indicated total PAHs levels in the range 22-106 µg/kg dry weight. All large towns or industrial areas from all countries of the basin were affected. Analysis of the origin of contamination demonstrated mainly a pyrolytic origin except in some areas such as Maddalena, Napoli, Alger, and Cornigliano (Genova). Statistical analysis of the PAHs accumulation data enabled the characterisation and ranking of each coastal area. The overall results give scientific and technical basis for large-scale monitoring of the PAH contamination in the entire western Mediterranean basin.


Asunto(s)
Bivalvos/química , Hidrocarburos Policíclicos Aromáticos/análisis , Contaminantes Químicos del Agua/análisis , Animales , Monitoreo del Ambiente , Mar Mediterráneo
17.
Talanta ; 221: 121412, 2021 Jan 01.
Artículo en Inglés | MEDLINE | ID: mdl-33076057

RESUMEN

Herein, we developed and designed a novel ratiometric optical chemisensor film for determining Al(III) and Cu(II) in low concentration ranges. The chemisensor film consists of (a) antibacterial drug Ciprofloxacin (CPFX) [1-cyclopropyl-6-fluoro1,4-dihydro-4-oxo-7-(piperaziny-l-yl) quinolone-3carboxylic acid] and (b) a reference dye 5,10,15,20- tetrakis (pentafluorophenyl) porphyrin (TFPP) in a polyvinyl chloride (PVC) matrix. PVC was applied as a homogeneous system for mixing CPFX and TFPP. The emission intensity of the CPFX in the PVC matrix varies depending on the concentrations of the Al(III) and Cu(II) ions. When the sensor film is immersed in different Al(III) concentrations, a significant fluorescence enhancement of the CPFX at (427 nm) is observed. Furthermore, the fluorescence intensity of the red emission of the TFPP dye at (644 nm) does not alter. However, in the presence of Cu(II) ions, a considerable emission quenching of the CPFX peak at (427 nm) is observed. PVC provides a great permeability and penetration facilities of dissolved ions that make the sensor film sensitive to Al(III) or Cu(II) changes outside the matrix. The film displays immense sensitivity depending on their distinctive optical characteristics of CPFX and detection capabilities within a low detection limit LOD for Al(III) and Cu(II). The LOD values were estimated to be 2.05 x 10-7 M and 1.04 x 10-7 M respectively with a relative standard deviation RSDr (1%, n=3). Density functional theory (DFT) and the time-dependent DFT (TDDFT) theoretical calculations were performed to study Cu(II) and Al(III) complexation structures and their electronic properties in solution and in the sensor film. The interference of the chemisensor film was examined using different cations and the chemisensor provides significant selectivity. We develop a new ratiometric chemisensor based on PVC polymer film for Al(III) and Cu(II) detection.


Asunto(s)
Cobre , Preparaciones Farmacéuticas , Antibacterianos , Ciprofloxacina , Polímeros
18.
Nanoscale ; 13(14): 6786-6797, 2021 Apr 14.
Artículo en Inglés | MEDLINE | ID: mdl-33690747

RESUMEN

The electron flow between a metallic aggregate and an organic molecule after excitation with light is a crucial step on which hybrid photovoltaic nanomaterials are based. So far, designing such devices with the help of theoretical approaches has been heavily limited by the computational cost of quantum dynamics models able to track the evolution of the excited states over time. In this article, we present the first application of the time-dependent density functional tight-binding (TD-DFTB) method for an experimental nanometer-sized gold-organic system consisting of a hexyl-protected Au25 cluster labelled with a pyrene fluorophore, in which the fluorescence quenching of the pyrene is attributed to the electron transfer from the metallic cluster to the dye. The full quantum rationalization of the electron transfer is attained through quantum dynamics simulations, highlighting the crucial role of the protecting ligand shell in electron transfer, as well as the coupling with nuclear movement. This work paves the way towards the fast and accurate theoretical design of optoelectronic nanodevices.

19.
J Mol Model ; 25(3): 85, 2019 03 02.
Artículo en Inglés | MEDLINE | ID: mdl-30826938

RESUMEN

The authors have retracted this article [1] due to an error in obtaining permission to use the data generated at the Synchrotron SOLEIL. All authors agree to this retraction.

20.
J Comput Chem ; 29(13): 2279-87, 2008 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-18548522

RESUMEN

This article presents results of first-principles calculations of quadrupolar parameters measured by solid-state nuclear magnetic measurement (NMR) spectroscopy. Different computational methods based on density functional theory were used to calculate the quadrupolar parameters. Through a series of illustrations from different areas of solid state inorganic chemistry, it is shown how quadrupolar solid-state NMR properties can be tackled by a theoretical approach and can yield structural information.

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