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1.
Bioorg Med Chem ; 15(22): 7058-65, 2007 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-17845855

RESUMO

This study was undertaken to investigate the free radical-scavenging and antioxidant activities of various structurally related hydroquinones including hydroxynaphthalenones and dihydroxyanthracenones. Electron spin resonance spectroscopy and spin trapping techniques were used to evaluate the ability of hydroquinones to scavenge hydroxyl, diphenylpicrylhydrazyl, and galvinoxyl radicals. In addition, the oxygen radical absorbing capacity assay using fluorescein (ORAC-FL) was used to obtain the relative antioxidant capacity of these radicals. The rate constants of the first H atom abstraction by 2,2-diphenyl-2-picrylhydrazyl (k(2)), were obtained under pseudo-first-order conditions. The free radical-scavenging activities and k(2) values discriminate well between hydroxynaphthalenones and dihydroxyanthracenones, showing that the latter have better antioxidant properties. The aforementioned experimental data agree with quantum-chemical results demonstrating the relevance of intramolecular H bonding to radical-scavenging activities.


Assuntos
Antracenos/química , Antioxidantes/química , Sequestradores de Radicais Livres/química , Naftalenos/química , Oxigênio/química , Animais , Antracenos/farmacologia , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Espectroscopia de Ressonância de Spin Eletrônica/métodos , Sequestradores de Radicais Livres/farmacologia , Ligação de Hidrogênio , Cinética , Camundongos , Estrutura Molecular , Naftalenos/farmacologia , Oxigênio/antagonistas & inibidores , Oxigênio/metabolismo , Espécies Reativas de Oxigênio/química , Espécies Reativas de Oxigênio/metabolismo , Reprodutibilidade dos Testes , Sensibilidade e Especificidade
2.
Bioorg Med Chem ; 14(13): 4664-9, 2006 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-16504517

RESUMO

A series of tricyclic hydroquinones, incorporating a carbonyl group in the ortho position relative to the phenol function, were tested as inhibitors of oxygen uptake against the TA3 mouse carcinoma cell line and its multidrug-resistant variant TA3-MTX-R. The title compound, which proved to be the most active one, also exhibited low micromolar dose-dependent growth inhibition of the human tumor U937 cell line (human monocytic leukemia). A tentative structure-activity relationship is proposed for these substances. A comparison between the cytotoxicities of the title compound and 4,4-dimethyl-5,8-dihydroxynaphthalene-1-one, with their activities as inhibitors of oxygen uptake by the TA3-MTX-R cell line, is presented. Also, the inhibition of oxygen uptake by 6-(4-methylpent-3-enyl)-1,4-naphthoquinone was determined and compared with its reported cytotoxicity toward P-388 (murine lymphocytic leukemia), A-549 (human lung carcinoma), HT-29 (human colon carcinoma), and MEL-28 (human melanoma) cells. The inhibition of oxygen uptake by TA3-MTX-R cells is useful as a quick test for preliminary screening of possible anticancer activity.


Assuntos
Antracenos/química , Antracenos/farmacologia , Antineoplásicos/química , Antineoplásicos/farmacologia , Naftalenos/química , Naftalenos/farmacologia , Consumo de Oxigênio/efeitos dos fármacos , Animais , Linhagem Celular Tumoral , Respiração Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais/métodos , Humanos , Camundongos , Neoplasias/metabolismo , Relação Estrutura-Atividade
3.
J Agric Food Chem ; 53(26): 10080-4, 2005 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-16366698

RESUMO

The effect on mycelial growth of the fungus Botrytis cinerea of a set of structurally related tricyclic hydroquinones [9,10-dihydroxy-4,4-dimethyl-2,3,5,8-tetrahydroantracen-1(4H)-one and 9,10-dihydroxy-4,4-dimethyl-5,8-dihydroanthracen-1(4H)-one derivatives] and tricyclic quinones [4,4-dimethylanthracen-1,9,10(4H)-trione derivatives] was studied. In general, the anthraquinones presented higher activity than the anthrahydroquinones. Anthraquinone and anthrahydroquinone derivatives with methyl groups on the A ring showed higher antifungal activity than the unsubstituted ones, 4,4,6,7-tetramethyl-(4H)-anthracene-1,9,10-trione being the most active compound of this set. The presence of a polar group such as hydroxymethyl reduced the activity. The effect of two anthrahydroquinones and two anthraquinones on the conidia germination of the fungus was also determined. Anthrahydroquinones did not affect the germination. The most active compound was 4,4-dimethylanthracene-1,9,10(4H)-trione, with 100% inhibition of germination at 7 h of incubation. These results again suggest that the structure of the anthraquinones is important in exerting an antifungal effect on B. cinerea. Furthermore, possible mechanisms of action of compound 4,4-dimethylanthracene-1,9,10(4H)-trione were studied. This compound did not produce lipoperoxidation of membrane and did not induce the formation of oxygen reactive species, but it was able to permeabilize the plasmatic membrane of B. cinerea, increasing the phosphorus concentration in the intracellular medium.


Assuntos
Antraquinonas/farmacologia , Botrytis/efeitos dos fármacos , Fungicidas Industriais , Botrytis/crescimento & desenvolvimento , Membrana Celular/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Esporos Fúngicos/efeitos dos fármacos , Esporos Fúngicos/crescimento & desenvolvimento , Relação Estrutura-Atividade
4.
Bioorg Med Chem ; 10(9): 3057-60, 2002 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-12110329

RESUMO

A set of structurally related compounds incorporating a carbonyl group in the ortho position with regard to a phenol function were tested against the TA3 mouse carcinoma cell line and its multidrug-resistant variant TA3-MTX-R. The series consists of 2'-hydroxyacetophenone, 4'-hydroxyacetophenone 2',5'-dihydroxyacetophenone, 4-acetyl-3,3-dimethyl-5-hydroxy-2-morpholino-2,3-dihydrobenzobfuran, five 4,4-dimethyl-5,8-dioxygenated naphtalene-1-ones and three 4,4-dimethyl-5,8-dioxygenated tetralones. A tentative structure-activity relationship was found for this family of substances, suggesting that a coplanar ortho-carbonyl-1,4-hydroquinone motif is able to cause inhibition of cellular respiration.


Assuntos
Respiração Celular/efeitos dos fármacos , Fenóis/síntese química , Animais , Resistência a Múltiplos Medicamentos , Cetonas/síntese química , Cetonas/farmacologia , Camundongos , Consumo de Oxigênio/efeitos dos fármacos , Fenóis/farmacologia , Relação Estrutura-Atividade , Células Tumorais Cultivadas
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