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1.
J Colloid Interface Sci ; 469: 296-309, 2016 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-26897566

RESUMO

We successfully immobilized metalloporphyrins (MeP) in mesoporous silica coating magnetite spheres. In this sense, we prepared two different classes of core@shell supports, which comprise aligned (Fe3O4-AM-MeP, MeP=FeP or MnP) and non-aligned (Fe3O4-NM-MeP, MeP=FeP or MnP) mesoporous magnetic structures. X-ray diffractometry and energy dispersive X-ray spectroscopy confirmed the mesoporous nature of the silica shell of the materials. Magnetization measurements, scanning and transmission electron microscopies (SEM/TEM), electrophoretic mobility (ζ-potential), and infrared spectroscopy (FTIR) also confirm the composition and structure of the materials. The catalysts maintained their catalytic activity during nine reaction cycles toward hydrocarbon oxidation processes without detectable catalyst leaching. The catalysis results revealed a biomimetic pattern of cytochrome P450-type enzymes, thus confirming that the prepared materials are can effectively mimic the activity of such groups.


Assuntos
Materiais Biomiméticos/química , Óxido Ferroso-Férrico/química , Hidrocarbonetos/química , Metaloporfirinas/química , Microesferas , Dióxido de Silício/química , Catálise , Estrutura Molecular , Oxirredução , Tamanho da Partícula , Porosidade , Propriedades de Superfície
2.
Rev. bras. farmacogn ; 23(4): 621-629, Aug. 2013. ilus, tab
Artigo em Inglês | LILACS | ID: lil-686640

RESUMO

Monensin A is an important commercially available natural product isolated from Streptomyces cinnamonensins that shows antibiotic and anti-parasitic activities. This molecule has a significant influence in the antibiotic market, but until now there are no studies on putative metabolite formations. Bioorganic catalysts applying metalloporphyrins and mono-oxygen donors are able to mimic the cytochrome P450 reactions. This model has been employed for natural product metabolism studies affording several new putative metabolites and in vivo experiments confirming the relevance of this procedure. In this work we evaluated the potential of 10,15,20-tetrakis (pentafluorophenyl) porphyrin metal(III) chloride [Fe(TFPP)Cl] catalyst models to afford a putative monensin A metabolite. Oxidation agents such as meta-chloroperoxy benzoic acid, iodosylbenzene, hydrogen peroxide 30 wt.% and tert-butyl hydroperoxide 70 wt.%, were used to investigate different reaction conditions, in addition to the analysis of the influence of the solvent. The quantification of total monensin A conversion and the structure of the new hydroxylated putative metabolite were proposed based on electrospray ionization tandem mass spectrometry analysis. The porphyrin tested, afforded moderate conversions of monensin A in all reaction conditions and the selectivity was found to be dependent on the oxidation/medium employed.

3.
Photochem Photobiol ; 88(4): 774-81, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22283143

RESUMO

A series of meso-substituted tetra-cationic porphyrins, which have methyl and octyl substituents, was studied in order to understand the effect of zinc chelation and photosensitizer subcellular localization in the mechanism of cell death. Zinc chelation does not change the photophysical properties of the photosensitizers (all molecules studied are type II photosensitizers) but affects considerably the interaction of the porphyrins with membranes, reducing mitochondrial accumulation. The total amount of intracellular reactive species induced by treating cells with photosensitizer and light is similar for zinc-chelated and free-base porphyrins that have the same alkyl substituent. Zinc-chelated porphyrins, which are poorly accumulated in mitochondria, show higher efficiency of cell death with features of apoptosis (higher MTT response compared with trypan blue staining, specific acridine orange/ethidium bromide staining, loss of mitochondrial transmembrane potential, stronger cytochrome c release and larger sub-G1 cell population), whereas nonchelated porphyrins, which are considerably more concentrated in mitochondria, triggered mainly necrotic cell death. We hypothesized that zinc-chelation protects the photoinduced properties of the porphyrins in the mitochondrial environment.


Assuntos
Quelantes/farmacologia , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Fármacos Fotossensibilizantes/farmacologia , Porfirinas/farmacologia , Zinco/química , Laranja de Acridina , Transporte Biológico/efeitos dos fármacos , Transporte Biológico/efeitos da radiação , Morte Celular/efeitos dos fármacos , Morte Celular/efeitos da radiação , Membrana Celular/efeitos dos fármacos , Membrana Celular/efeitos da radiação , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/efeitos da radiação , Quelantes/química , Citocromos c/análise , Etídio , Formazans , Fase G1/efeitos dos fármacos , Fase G1/efeitos da radiação , Células HeLa , Humanos , Luz , Potencial da Membrana Mitocondrial/efeitos da radiação , Mitocôndrias/metabolismo , Mitocôndrias/efeitos da radiação , Processos Fotoquímicos , Fármacos Fotossensibilizantes/química , Porfirinas/química , Espécies Reativas de Oxigênio/metabolismo , Sais de Tetrazólio
4.
J Org Chem ; 76(21): 8824-32, 2011 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-21932835

RESUMO

The synthesis and photophysical evaluation of new chlorin derivatives are described. The Diels-Alder reaction between protoporphyrin IX dimethyl ester and substituted maleimides furnishes endo-adducts that completely prevent the self-aggregation of the chlorins. Fluorescence, resonant light scattering (RLS) and (1)H NMR experiments, as well as X-ray crystallographic have demonstrated that the configurational arrangement of the synthesized chlorins prevent π-stacking interactions between macrocycles, thus indicating that it is a nonaggregating photosensitizer with high singlet oxygen (Φ(Δ)) and fluorescence (Φ(f)) quantum yields. Our results show that this type of synthetic strategy may provide the lead to a new generation of PDT photosensitizers.


Assuntos
Fármacos Fotossensibilizantes/química , Fármacos Fotossensibilizantes/síntese química , Porfirinas/química , Oxigênio Singlete/química , Cristalografia por Raios X , Fluorescência , Estrutura Molecular , Espectrofotometria
5.
J Colloid Interface Sci ; 350(1): 148-54, 2010 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-20598704

RESUMO

The interaction between a hydrophobically modified 5,10,15,20-tetrakis(4-N-tetradecyl-pyridyl) porphyrin and three phospholipids: two negatively charged, DMPA (the sodium salt of dimyristoyl-sn-glycero-phosphatidyl acid) and DMPG (the sodium salt of 1,2-dimyristoyl-sn-glycero-3-[phospho-rac-(1-glycerol)]) and a zwitterionic DMPC (dimyristoyl-sn-glycero-phosphatidylcholine), were studied by means of surface pressure isotherms and spectroscopic methods. The interaction results in partial or total metallation of the porphyrin with zinc ions in the presence of negatively charged phospholipids, as attested by UV-vis and luminescence spectroscopy of the transferred films. In the presence of the zwitterionic phospholipid no insertion of zinc ion in the porphyrin ring is detected. These results are relevant for the understanding of photosensitizer-lipid-carrier binding for use in photodynamic therapy.


Assuntos
Fosfolipídeos/química , Porfirinas/química , Zinco/química , Íons , Microscopia de Fluorescência , Modelos Químicos , Estrutura Molecular , Propriedades de Superfície
6.
Biol Pharm Bull ; 33(5): 912-6, 2010.
Artigo em Inglês | MEDLINE | ID: mdl-20460777

RESUMO

Synthetic metalloporphyrins, in the presence of monooxygen donors, are known to mimetize various reactions of cytochrome P450 enzymes systems in the oxidation of drugs and natural products. The oxidation of piperine and piplartine by iodosylbenzene using iron(III) and manganese(III) porphyrins yielded mono- and dihydroxylated products, respectively. Piplartine showed to be a more reactive substrate towards the catalysts tested. The structures of the oxidation products were proposed based on electrospray ionization tandem mass spectrometry.


Assuntos
Alcaloides/metabolismo , Benzodioxóis/metabolismo , Biomimética , Compostos Férricos/química , Ferro/química , Manganês/química , Piperidinas/metabolismo , Piperidonas/metabolismo , Alcamidas Poli-Insaturadas/metabolismo , Porfirinas/química , Produtos Biológicos , Catálise , Sistema Enzimático do Citocromo P-450/química , Inativação Metabólica , Iodobenzenos/metabolismo , Oxirredução , Porfirinas/síntese química , Oxigênio Singlete , Espectrometria de Massas por Ionização por Electrospray
7.
J Org Chem ; 74(20): 7962-5, 2009 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-19743877

RESUMO

Syntheses of two water-soluble phthalocyanines (Pc) containing 5-aminolevulinic acid (ALA) linked to the core structure are described. These compounds were prepared by using original functionalizations, and they present remarkable structural and photophysical features, indicating that they could be applied to photodynamic therapy (PDT).


Assuntos
Ácido Aminolevulínico/síntese química , Indóis/síntese química , Água/química , Ácido Aminolevulínico/química , Indóis/química , Isoindóis , Estrutura Molecular , Solubilidade
8.
Photochem Photobiol Sci ; 8(2): 233-40, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19247516

RESUMO

A series of photosensitizers (PS), which are meso-substituted tetra-cationic porphyrins, was synthesized in order to study the role of amphiphilicity and zinc insertion in photodynamic therapy (PDT) efficacy. Several properties of the PS were evaluated and compared within the series including photophysical properties (absorption spectra, fluorescence quantum yield Phif, and singlet oxygen quantum yield PhiDelta), uptake by vesicles, mitochondria and HeLa cells, dark and phototoxicity in HeLa cells. The photophysical properties of all compounds are quite similar (Phif

Assuntos
Fármacos Fotossensibilizantes/química , Porfirinas/química , Fluorescência , Células HeLa , Humanos , Luz , Mitocôndrias/fisiologia , Mitocôndrias/efeitos da radiação , Consumo de Oxigênio/efeitos da radiação , Fotoquimioterapia/métodos , Teoria Quântica , Zinco/fisiologia
9.
J Colloid Interface Sci ; 323(1): 98-104, 2008 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-18455176

RESUMO

A new mesoporous catalyst was prepared by the reaction between 3-aminopropyltrimethoxisylane and Cu(II)-hexadecafluorophthalocyanine, followed by co-condensation of tetraethylorthosilicate around a micelle formed by n-dodecylamine. The surfactant was removed from the pores by continuous extraction with ethanol, giving the Si-CuF16Pc catalyst. This catalyst was characterized by SEM, FTIR, TGA, 29Si NMR, N2 adsorption and X-ray diffraction. SEM images confirmed that the catalyst material is formed by nanoaggregates with a diameter of 100 nm. N2 adsorption isotherms showed that Si-CuF16Pc has a surface area of approximately 200 m2 g(-1) and a porous diameter of 7.7 nm, characterizing the mesoporosity of this product. This novel material shows an excellent photocatalytic activity, degrading almost 90% of 2,4-dichlorophenoxyacetic acid (2,4-D) up to 30 min, while only approximately 40% of photodegradation was obtained in its absence.


Assuntos
Ácido 2,4-Diclorofenoxiacético/química , Indóis/química , Compostos Organometálicos/química , Praguicidas/química , Fotoquímica/métodos , Dióxido de Silício/química , Adsorção , Aminas/química , Bioquímica/métodos , Catálise , Luz , Teste de Materiais , Microscopia Eletrônica de Varredura , Modelos Químicos , Tensoativos , Difração de Raios X
10.
Rapid Commun Mass Spectrom ; 20(23): 3605-11, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-17091537

RESUMO

Novel cationic porphyrin derivatives having a galactose or a bis(isopropylidene)galactose unit linked directly to a pyridine or to an aminophenyl group were characterized by electrospray tandem mass spectrometry (ESI-MS/MS). The electrospray mass spectra (ESI-MS) show the M(+) ions, since these porphyrins are already monocharged in solution. The fragmentation of these ions under ESI-MS/MS conditions was studied and it was found that elimination of the sugar residue as a radical (-163 or -243 Da) is a common fragmentation pathway. Loss of the sugar unit as a neutral fragment (-162 or -242 Da) and cross-ring fragmentations typical of glyco-derivatives are also observed for the pyridinium glycoporphyrins, but they are absent in the case of ammonium glycoporphyrins. The cationic beta-pyridiniumvinyl porphyrins show an atypical fragmentation due to the cleavage of the C(5)-C(6) bond of the sugar unit. Overall, the different patterns of fragmentation observed in the ESI-MS/MS spectra of the sugar pyridinium porphyrins and of the sugar ammonium phenyl porphyrins can give important information about the type of spacer between the porphyrin and the sugar unit.


Assuntos
Galactose/análise , Galactose/química , Porfirinas/análise , Porfirinas/química , Espectrometria de Massas por Ionização por Electrospray/métodos , Cátions
11.
An. acad. bras. ciênc ; 72(1): 59-66, mar. 2000.
Artigo em Inglês | LILACS | ID: lil-259479

RESUMO

New materials porphyrinosilica and metalloporphyrinosilica template have been obtained by a sol-gel processing where functionalyzed porphyrins and metalloporphyrins "building blocks" were assembled into a three-dimensional silicate network. The optimized conditions for preparation of these materials are reviseed. The monomer precursors porphyrinopropylsilyl and metalloporphyrinopropylsilyl preparation reactions and subsequent one pot sol-gel processing with tetraethoxysilane are discussed. In the case of metalloporphyrins the nitrogen base coordinates to the central metal and acts as a template in the molecular imprinting technique. UV-visible absorption spectroscopy, thermogravimetric analysis, electron paramagnetic resonance, nuclear magnetic spectra, infrared spectra, luminescence spectra, surface area and electron spectroscopy imaging of the materials are used to characterize the prepared materials. The catalytic activities of these metalloporphyrinosilica-template are compared.


Assuntos
Metaloporfirinas/metabolismo , Porfirinas/metabolismo , Silicatos , Catálise , Géis , Metaloproteínas/química , Metaloproteínas/metabolismo , Porfirinas/química
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