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1.
Toxicol Mech Methods ; 30(7): 536-545, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32544017

RESUMO

Coffee is the most popular hot beverage and caffeine is the most used psychoactive drug in the world. Roasting of coffee beans leads to the generation of minute quantities of undesirable compounds, such as furan. It is now thought that the toxicity of furan derives from its processing by CYP450 family of detoxifying enzymes, leading to the formation of cis-2-butene-1,4-dial (BDA). BDA has known cytotoxicity capacities, binding to proteins, nucleic acids, and glutathione (GSH). BDA also appears to mediate furan's toxic effects, since the inhibition of CYP450 family impedes the aforementioned toxicological effects of furan. There are some studies performed on furan's toxicity, but very few on BDA. Furthermore, the doses used in these studies appear to be fairly high when compared with the expected dosage one could be exposed to in a standard day. As such, to understand if furan and BDA could have toxic effects using more realistic doses and longer time frames, human and rat hepatocytes were exposed to furan or BDA for up to 96 h, and several biochemical parameters were assessed. We report here that human hepatocytes were more sensitive than rat's, in particular to furan, for we show a decrease in MTT reduction, ATP levels and increase in carbonyl formation and 8-OHdG accumulation in the longer time points. BDA was mostly ineffective, which we attribute to a low import rate into the cells. In conclusion, we show that there is potential for harm from furan in high doses, which should be carefully addressed.


Assuntos
Aldeídos/toxicidade , Café/toxicidade , Furanos/toxicidade , Hepatócitos/efeitos dos fármacos , Sementes/toxicidade , 8-Hidroxi-2'-Desoxiguanosina/metabolismo , Trifosfato de Adenosina/metabolismo , Animais , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Culinária , Dano ao DNA , Relação Dose-Resposta a Droga , Hepatócitos/metabolismo , Hepatócitos/patologia , Temperatura Alta , Humanos , Estresse Oxidativo/efeitos dos fármacos , Carbamilação de Proteínas/efeitos dos fármacos , Ratos , Especificidade da Espécie , Fatores de Tempo
2.
Chemphyschem ; 19(1): 82-92, 2018 Jan 05.
Artigo em Inglês | MEDLINE | ID: mdl-29136312

RESUMO

Purely organic chiral molecular assemblies in the solid state hold great potential for non-linear optical applications. Herein, a newly synthesised molecular system is reported, namely, dicinnamalacetone, an otherwise planar molecule that crystallises in a disordered non-centrosymmetric form with four different conformations having an overall predominance of a particular helicity. A combined experimental and theoretical approach, including single-crystal X-ray diffraction, Kurtz-Perry and ab initio methods, is employed to characterise the system and benchmark the performance of hybrid functionals for the prediction of non-linear optical properties and electronic excitations. Comparison of experiment and theory points to a particular set of hybrid functionals that provides an optimal description of this molecular system.

3.
J Environ Sci (China) ; 69: 77-84, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29941271

RESUMO

One of today's major challenges is to provide green materials for a cleaner environment. We have conducted studies on carbon dioxide (CO2) adsorption and conversion to valuable products by an ecofriendly approach based in chitosan/graphene oxide (CSGO) nanocomposite film. Rheological behavior indicates that the CSGO has a better solvation property than the pure chitosan. An adsorption capacity of 1.0152mmolCO2/g of CSGO nanocomposite at 4.6bar was observed. The catalytic behavior of the CSGO nanocomposite in the presence of tetra-n-butylammonium iodide (n-Bu4NI) as co-catalyst was evaluated for the cycloaddition of CO2 to epoxides, to give cyclic carbonates, in the absence of any solvent. These results strongly suggest that the CSGO nanocomposite may open new vistas towards the development of ecofriendly material for catalytic conversion and adsorption of CO2 on industrial scale.


Assuntos
Dióxido de Carbono/química , Quitosana/química , Compostos de Epóxi/química , Grafite/química , Modelos Químicos , Nanocompostos/química , Adsorção , Reação de Cicloadição
4.
Microb Pathog ; 105: 57-62, 2017 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-28189732

RESUMO

Invasive fungal infection is a problem that continues to challenge the healthcare sector. New antifungals and new therapeutic strategies are needed to address this challenge. We previously reported that the combination of a synthetic compound with a drug with known mechanism of action is a good strategy to treat aggressive and resistant fungi. Here we revisited our approach and synthesized structural analogues of flucytosine, which is a synthetic antifungal and is being studied for its use in combination therapy with other antifungal drugs. Pyrimidin-one and -thione (often known as DHPM's) as flucytosine analogues were obtained through a Biginelli reaction of corresponding aldehydes, ethylacetoacetate and urea/thiourea. Structure was confirmed by FTIR, 1HNMR, 13CNMR, COSY and MS (ESI+) analysis. All the newly synthesized derivatives were evaluated for the antifungal activity alone and in combination of two most commonly used antifungal drugs, amphotericin B and fluconazole against different clinically isolated Candida albicans strains. Minimum inhibitory concentration results confirmed that BG4 possess high antifungal activity against all the tested strains (MIC = 1-32 µg/ml). For all the combinations with amphotericin B and fluconazole, 37% were synergistic followed by 30% additive and 24% indifferent interactions. Interestingly, 9% antagonistic interaction was observed when BG1 and BG3 were combined with fluconazole, however, no antagonistic interaction was observed with amphotericin B. In-depth studies of all the synergies were done by constructing isobolograms with nine different ratio combinations. These results warrant the use of DHPM derivatives as chemosensitising agents which could lower down the dosages of the antifungal drugs to treat invasive fungal diseases.


Assuntos
Antifúngicos/farmacologia , Candida albicans/efeitos dos fármacos , Sinergismo Farmacológico , Flucitosina/análogos & derivados , Flucitosina/farmacologia , Antifúngicos/síntese química , Antifúngicos/química , Candida albicans/isolamento & purificação , Candidíase/microbiologia , Flucitosina/síntese química , Flucitosina/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Análise Espectral
5.
Molecules ; 21(4): 439, 2016 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-27043519

RESUMO

Photodynamic therapy (PDT) is a selective and minimally invasive therapeutic approach, involving the combination of a light-sensitive compound, called a photosensitizer (PS), visible light and molecular oxygen. The interaction of these per se harmless agents results in the production of reactive species. This triggers a series of cellular events that culminate in the selective destruction of cancer cells, inside which the photosensitizer preferentially accumulates. The search for ideal PDT photosensitizers has been a very active field of research, with a special focus on porphyrins and porphyrin-related macrocycle molecules. The present study describes the photophysical characterization and in vitro phototoxicity evaluation of 5,10,15,20-tetra(quinolin-2-yl)porphyrin (2-TQP) as a potential PDT photosensitizer. Molar absorption coefficients were determined from the corresponding absorption spectrum, the fluorescence quantum yield was calculated using 5,10,15,20-tetraphenylporphyrin (TPP) as a standard and the quantum yield of singlet oxygen generation was determined by direct phosphorescence measurements. Toxicity evaluations (in the presence and absence of irradiation) were performed against HT29 colorectal adenocarcinoma cancer cells. The results from this preliminary study show that the hydrophobic 2-TQP fulfills several critical requirements for a good PDT photosensitizer, namely a high quantum yield of singlet oxygen generation (Φ∆ 0.62), absence of dark toxicity and significant in vitro phototoxicity for concentrations in the micromolar range.


Assuntos
Neoplasias Colorretais/terapia , Fotoquimioterapia , Fármacos Fotossensibilizantes/química , Porfirinas/química , Animais , Células HT29 , Humanos , Luz , Estrutura Molecular , Fármacos Fotossensibilizantes/administração & dosagem , Porfirinas/administração & dosagem , Oxigênio Singlete/química , Espectrometria de Fluorescência
6.
Bioorg Med Chem ; 23(15): 4172-4180, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26164624

RESUMO

A series of compounds in which 2-(4-ethyl-2-pyridyl)-1H-imidazole was clubbed with substituted 1,3,4-oxadiazole was synthesized and subjected to antifungal activity evaluation. In vitro assays indicated that several clubbed derivatives had excellent antifungal activity against different strains of laboratory and clinically isolated Candida species. Structural Activity Relationship (SAR) studies revealed that the presence and position of substituents on the phenyl ring of the 1,3,4-oxadiazole unit, guides the antifungal potential of the compounds, where compound 4b, 4c and 4g were found to be active against all the tested fungal strains. Impairment of ergosterol biosynthesis upon the concomitant treatment of 4b, 4c and 4g, revealed the possible mechanisms of antifungal action of these compounds. Inhibitors snugly fitting the active site of the target enzyme, as revealed by molecular docking studies, may well explain their excellent inhibitory activity.


Assuntos
Antifúngicos/química , Antifúngicos/farmacologia , Imidazóis/química , Oxidiazóis/química , Relação Estrutura-Atividade , Candida/efeitos dos fármacos , Candida/metabolismo , Avaliação Pré-Clínica de Medicamentos/métodos , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Estrutura Molecular , Esteróis/metabolismo
7.
Acta Crystallogr Sect E Struct Rep Online ; 69(Pt 5): o705, 2013 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-23723859

RESUMO

In the title Schiff base, C21H14N4O4, the dihedral angle between the two nitro groups and the central benzene ring are 83.6 (5) and 2.6 (6)°. The anthracene ring system and the benzene ring make a dihedral angle of 0.7 (2)°. Intra-molecular N-H⋯O and C-H⋯N hydrogen bonds occur. In the crystal, C-H⋯O hydrogen bonds link the mol-ecules, forming chains along the b-axis direction.

8.
Artigo em Inglês | MEDLINE | ID: mdl-24046587

RESUMO

In the title compound, [K(C10H5ClO2F3)(H2O)] n , the two independent K(+) ions are located on a twofold rotation axis. For each of the cations, the distorted cubic coordination environment is defined by two F and four O atoms of symmetry-related 1,4-chloro-phenyl-4,4,4-tri-fluoro-butane-1,3-dionate anions and by two O atoms of water mol-ecules. The µ4-bridging character of the anion and the µ2-bridging of the water mol-ecule lead to the formation of layers parallel to (100). The coordinating water mol-ecules are also involved in O-H⋯O hydrogen bonds that reinforce the mol-ecular cohesion within the layers, which are stacked along [100]. The ß-diketonate anion is not planar, with an angle of 31.78 (10)° between the mean planes of the diketonate group and the chloro-phenyl ring.

9.
Artigo em Inglês | MEDLINE | ID: mdl-24046600

RESUMO

The asymmetric unit of the title compound, C24H16N2·0.5CH3OH, is comprised of two independent bathophenanthroline mol-ecules (systematic name: 4,7-diphenyl-1,10-phenanthroline) and one methanol mol-ecule. The bathophenanthroline mol-ecules are not planar as there is a considerable rotation of all terminal phenyl rings with respect to the central phenanthroline units [dihedral angles in the range 52.21 (12)-62.14 (10)°]. In addition, a non-negligible torsion is apparent in one of the phenanthroline units: the angle between the mean planes of the two pyridine rings is 14.84 (13)°. The methanol solvent mol-ecule is linked to both N atoms of a bathophenanthroline mol-ecule through a bifurcated O-H⋯(N,N) hydrogen bond.

10.
Environ Pollut ; 324: 121386, 2023 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-36868547

RESUMO

Catalytic carbon materials from used face masks (UFM) activated by peroxymonosulfate (PMS) were developed for the degradation of rhodamine B (RhB) dye in aqueous solution. The UFM-derived carbon (UFMC) catalyst had a relatively large surface area as well as active functional groups and promoted the generation of singlet 1O2 and radicals from PMS, giving a high RhB degradation performance (98.1% after 3 h) in the presence of 3 mM PMS. The UFMC could degrade only 13.7% at a minimal RhB dose of 10-5 M. The principal reactive oxygen species of sulphate (SO4•), hydroxyl radicals (•OH), and singlet 1O2 were discovered using electron paramagnetic resonance and radical scavenger studies. Finally, a toxicological plant and bacterial study was performed to demonstrate the potential non-toxicity of the degraded RhB water sample.


Assuntos
Carbono , Máscaras , Peróxidos
11.
Materials (Basel) ; 16(22)2023 Nov 08.
Artigo em Inglês | MEDLINE | ID: mdl-38005015

RESUMO

BODIPYs are bicyclic aromatic compounds with unique spectroscopic, photophysical, and chemical properties. This study aimed to find BODIPYs with characteristics biocompatible with human cell lines for possible use as imaging agents. Six BODIPY derivatives were synthesised with groups linked to boron, fluorine, phenol, or catechol, resulting in compounds with different physicochemical characteristics. NMR, absorption, and emission spectroscopy and mass spectrometry were subsequently used to characterise them. Afterwards, the biocompatibility of these compounds was evaluated using MTT, SRB, and cellular uptake assays in A549 and H1299 cell lines. Furthermore, a haemolysis assay was performed on human blood cells. To summarise the main results, BODIPYs 1 to 4 showed considerable fluorescence. In contrast, BODIPYs 5 and 6 showed very weak fluorescence, which could be related to the presence of the catechol group and its quenching properties. Regarding biocompatibility, all compounds had metabolic activity and viability above 80% and 70%, respectively. BODIPYs 3 and 6 presented the most consistent data, demonstrating good uptake and, in general, haemolytic activity below 25%. In conclusion, the cytotoxic effects of the compounds were not considerable, and the presence of cyclic alkoxides in BODIPYs 3 and 6 may introduce exciting features that should be highlighted for dual imaging for BODIPY 3 due to its fluorescence or for radioactive labelling in the case of both BODIPYs.

12.
Materials (Basel) ; 17(1)2023 Dec 22.
Artigo em Inglês | MEDLINE | ID: mdl-38203929

RESUMO

Water pollution poses a global threat to ecosystems and human health and is driven by the presence of various contaminants in wastewater, including nano- and microplastics. Despite the magnitude of this problem, the majority of global wastewater is released untreated into water bodies. To combat this issue, a multi-strategy approach is needed. This study explores a circular economy-based solution for treating emerging pollutants, particularly wastewater from ophthalmic spectacle lens production. Our approach integrates solid waste materials into polymeric and cement matrices while also utilising wastewater for microalgae cultivation. This innovative strategy focuses on biomass generation and economic valorisation. By adopting a circular economy model, we aim to transform environmental pollutants from wastewater into valuable organic products. A key component of our approach is the utilisation of microalgae, specifically Nannochloropsis sp., known for its high lipid content and resilience. This microalgae species serves as a promising biobased feedstock, supporting the production of innovative biobased products, such as biopolymers, for ophthalmic lens manufacturing. Our interdisciplinary approach combines microalgae technology, analytical chemistry, cement production, and polymer processing to develop a sustainable circular economy model that not only addresses environmental concerns, but also offers economic benefits. This study underscores the potential of harnessing high-value products from waste streams and underscores the importance of circular economy principles in tackling pollution and resource challenges.

13.
Acta Chim Slov ; 59(2): 353-8, 2012 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24061252

RESUMO

Diffusion coefficients, thermodynamic and mobility factors of iron salts in aqueous solutions are estimated from Onsager-Fuoss model. The influence of the ion size parameter a, "mean distance of closest approach of ions", determined from different approaches, on the variation of diffusion coefficients with concentration, is also discussed. The aim of this work is to have a better understanding of the structure of these systems and of the thermodynamic behaviour of iron salts in aqueous media.

14.
Acta Crystallogr Sect E Struct Rep Online ; 68(Pt 12): o3462-3, 2012 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-23476273

RESUMO

Mol-ecules of the title compound, C52H38N4O8, are located on an inversion center so that the asymmetric cell contains one half of the mol-ecule. The macrocycle exhibits a ruffled conformation with a maximum deviation of 0.16 Šfor the 24 macrocycle atoms: the dihedral angle between adjacent five-membered rings is 5.13 (19)°. The benzene rings are rotated by 70.25 (19)° with respect to their adjacent protonated five-membered rings, and by 65.56 (19)° with respect to the unprotonated rings. The porphyrin conformation is supported by bifurcated N-H⋯(N,N) hydrogen bonds. The structure contained poorly resolved solvent mol-ecules in voids of volume 217 Å(3) per unit cell. The latter were treated using the SQUEEZE routine in PLATON [Spek (2009 ▶). Acta Cryst. D65, 148-155]. As the solvent could not be identified exactly, it was not included in the calculation of the overall formula weight, density and absorption coefficient.

15.
Acta Chim Slov ; 58(4): 797-801, 2011 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-24061131

RESUMO

The estimation of numerical values of the mean distance of closest approach of ions, a, of lanthanides and actinides ion salts in aqueous solutions, determined from activity coefficients, as well as from different theoretical approaches, is presented and discussed.

16.
Acta Crystallogr Sect E Struct Rep Online ; 67(Pt 2): m160, 2011 Jan 12.
Artigo em Inglês | MEDLINE | ID: mdl-21522841

RESUMO

In the monomeric title complex, [Cu(C(6)H(3)BrNO(2))(NO(3))(H(2)O)(2)], the Cu(II) ion is coordinated by a bidentate 6-bromo-picolinate ion, one nitrate ion and two water mol-ecules in a geometry inter-mediate between five- and six-coordinate. Conventional O-H⋯O hydrogen bonds link the complex mol-ecules, forming layers parallel to the ab plane.

17.
Acta Chim Slov ; 57(2): 410-4, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-24061738

RESUMO

Mutual diffusion coefficients (interdiffusion coefficients) have been measured for sodium fluoride in water at 298.15 K and 310.15 K at concentrations between 0.003 mol dm-3 and 0.05 mol dm-3. The diffusion coefficients were measured using a conductimetric cell. The experimental mutual diffusion coefficients are discussed on the basis of the Onsager-Fuoss model. The limiting molar conductivity of the fluoride ion in these solutions at 310.15 K has been estimated using these results.

18.
MethodsX ; 7: 101083, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33102154

RESUMO

A rapid reverse phase high-performance liquid chromatography (RP-HPLC) method was developed and validated for the simultaneous quantification of paracetamol, ibuprofen, olanzapine, simvastatin and simvastatin acid in the context of microalgae bioremediation. The method was validated according to the guidelines of the US Food and Drug Administration (FDA), the International Conference on Harmonization (ICH), and Eurachem with respect to system suitability, linearity, accuracy, precision, recovery, limits of detection and quantification, ruggedness, selectivity and specificity. The estimated limits of detection and quantification were, respectively, 0.03 and 0.10 µg mL-1 for paracetamol, 0.03 and 0.09 µg mL-1 for ibuprofen, 0.04 and 0.13 µg mL-1 for olanzapine, 0.27 and 0.83 µg mL-1 for simvastantin, and 0.05 and 0.14 µg mL-1 for simvastantin acid. The inter-day and intra-day precision results were within the acceptance limit of relative standard deviation (%RSD) of less than 2, and the percentage recovery was found to be within the required limits of 80-110%. The developed method is rapid, linear, precise, robust and accurate, and has been successfully applied to the determination of the above common pharmaceutical products during microalgae bioremediation.

19.
J Phys Chem B ; 113(35): 11808-21, 2009 Sep 03.
Artigo em Inglês | MEDLINE | ID: mdl-19663434

RESUMO

Relationships have been obtained between intermonomer torsional angle and NMR chemical shifts ((1)H and (13)C) for isolated chains of two of the most important poly(9,9-dialkylfluorenes), poly[9,9-bis(2-ethylhexyl)fluorene-2,7-diyl] (PF2/6) and the copolymer poly(9,9-dioctylfluorene-co-[2,1,3]benzothiadiazole-4,7-diyl) (F8BT), using DFT calculations. The correlations provide a model for NMR spectral data interpretation and the basis for analysis of conformational changes in poly(9,9-dialkylfluorene-2,7-diyl)s. The correlations obtained for PF2/6 indicate that the (13)C chemical shifts of the aromatic carbons close to the intermonomer connection (C1, C2, and C3) have minimum values at planar conformations (0 degrees and 180 degrees ) and maximum values at 90 degrees conformations. In contrast, the (1)H chemical shifts of the corresponding aromatic ortho protons (Ha and Hb) are greatest for planar conformations, and the minimum values are seen for 90 degrees conformations. For the F8BT copolymer, similar relationships are observed for the (1)H (Ha, Hb, and Hc) aromatic shifts. Considering the aromatic carbons of F8BT, the behavior of C2, C4, C5, and C6 is similar to that found for the PF2/6 carbons. However, C1 and C3 of the fluorene moiety behave differently with varying torsion angle. These are in close proximity to the fluorene-benzothiadiazole linkage and are markedly affected by interactions with the thiadiazole unit such that delta(C1) is a maximum for 180 degrees and a minimum for 0 degrees , whereas delta(C3) is a maximum for 0 degrees and minimum for 180 degrees. We have studied the (1)H and (13)C spectra of the two polymers at temperatures between -50 degrees C and +65 degrees C. The observed changes to higher or lower frequency in the aromatic resonances were analyzed using these theoretical relationships. Fluorescence studies on PF2/6 in chloroform solution suggest there are no significant interchain interactions under these conditions. This is supported by variable-temperature NMR results. Polymer-solvent and polymer intramolecular interactions were found to be present and influence all of the alkylic and one of the aromatic (1)H resonances (Hb). The detailed attribution of the (1)H and (13)C NMR spectra of the two polymers was made prior to the establishment of the relationships between torsion angle and NMR chemical shifts. This was carried out through DFT calculation of the (1)H and (13)C shielding constants of the monomers, coupled with distortionless enhancement by polarization transfer and heteronuclear correlation NMR spectra. Several DFT levels of calculation were tested for both optimization of structures and shielding constants calculation. The B3LYP/6-31G(d,p) method was found to perform well in both cases.


Assuntos
Fluorenos/química , Espectroscopia de Ressonância Magnética/métodos , Algoritmos , Clorofórmio , Modelos Químicos , Modelos Moleculares , Modelos Teóricos , Conformação Molecular , Polímeros/química , Solventes/química , Espectrometria de Fluorescência/métodos , Temperatura
20.
Acta Crystallogr Sect E Struct Rep Online ; 65(Pt 6): o1255, 2009 May 14.
Artigo em Inglês | MEDLINE | ID: mdl-21583120

RESUMO

The title compound, C(20)H(26)N(4), is composed of two (6-methyl-2-pyridyl)methyl-ene units linked by a 1,6-diamine hexane chain. The mol-ecule has C(i) symmetry with the inversion center situated at the mid-point of the central C-C bond. The alkyl chain has an all-trans conformation, with all the non-H atoms sharing the same plane [maximum deviation 0.004 (3) Å]. The pyridylmethyl-ene groups are also planar [maximum deviation 0.009 (3) Å], making an angle of 53.78 (19)° with the hexane chain plane. In the crystal, the mol-ecules assemble in layers, stacking along the a axis. The stacks are hold together by attractive interactions between π electron systems.

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