Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 1 de 1
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Biophys Chem ; 35(2-3): 303-12, 1990 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-2397276

RESUMO

Some of the photophysical properties (stationary absorbance and fluorescence, fluorescence decay times and singlet oxygen quantum yields) of pheophorbide a, metal-free, ClAl-, Cu- and Mg-t-butyl-substituted phthalocyanines, metal-free, ClAl- and Cu-t-butyl-substituted naphthalocyanines and of a number of tetraphenylporphyrins (5,10,15,20-tetraphenylporphyrin, 5,10,15,20-tetra(m-hydroxyphenyl)porphyrin, 5,10,15,20-tetra(p-hydroxyphenyl)porphyrin) have been studied in comparison with hematoporphyrin IX in order to select potent photosensitizers for the photodynamic treatment of cancer. The photodynamic activity of these compounds was investigated using Lewis lung carcinoma in mice. As a consequence of the photophysical parameters (relatively short singlet state lifetimes, and high singlet oxygen quantum yields) the photodynamic activities of pheophorbide a, t-butyl-substituted ClAl-phthalocyanine and ClAl-naphthalocyanine were selected for study in greater detail. Under the conditions employed in the present study, pheophorbide a was found to be the most effective sensitizer, as judged from its strong absorption at the excitation wavelength as compared with the hematoporphyrin derivative and greater singlet oxygen quantum yield relative to the phthalocyanines and naphthalocyanines. The photodynamic activity was observed to be strongly dependent on the photophysical parameters of the compounds. The primary mechanism underlying the photodynamic activity of these sensitizers probably consists of energy transfer from the lowest triplet state of the dyes to molecular oxygen, resulting in the formation of singlet oxygen (type II of photosensitization).


Assuntos
Fotoquimioterapia , Pirróis/análise , Animais , Fenômenos Químicos , Físico-Química , Feminino , Fluorescência , Medições Luminescentes , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA , Metástase Neoplásica , Neoplasias Experimentais/tratamento farmacológico , Fotoquímica , Pirróis/farmacologia , Espectrometria de Fluorescência , Espectrofotometria Ultravioleta
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...