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Phenols and their derivatives commonly exist in the environment. These compounds are used as the components of dyes, polymers, drugs and other organic substances. The presence of phenols in the ecosystems is also related with production and degradation of numerous pesticides and the generation of industrial and municipal sewages. Some phenols are also formed during natural processes. These compounds may be substituted with chlorine atoms, may be nitrated, methylated or alkylated. Both phenols and catechols are harmful ecotoxins. Toxic action of these compounds stems from unspecified toxicity related to hydrophobocity and also to the generation of organic radicals and reactive oxygen species. Phenols and catechols reveal peroxidative capacity, they are hematotoxic and hepatotoxic, provoke mutagenesis and carcinogenesis toward humans and other living organisms.
An inhibition of growth of Chlorella vulgaris, Beijerinck 1980 laboratory cultures carried out under different conditions caused by benzene, phenol and catechol was investigated. Each of the investigated substances was added to the culture medium at 4 or 5 different concentrations, directly before inoculation. The cultures were carried up to the stationary phase of growth. The density of alga cell suspension in the culture medium was determined with the use of a Bürker hemocytometer as well as EC50/96 and EC 50/Tmax values. It was stated that under some conditions it was possible to estimate the toxicity of the investigated substances, either in open cultures (flasks with microbiological corks, type I cultures) or closed (flasks with ground corks, type II cultures), but in this second case with the presence of NaHCO3 as an additional source of C02. The results presented in this paper indicate a relatively high toxicity of benzene and its investigated metabolites, phenol and catechol, as well as its dependence on conditions in the investigated cultures.
We estimated the toxic effect of benzene, phenol, and catechol on the logarithmic phase of growth of Chlorella vulgaris, Beijerinck 1890 cultures; the compounds show various degrees of toxicity to the algae. A concept was developed concerning each compound's toxicity index EC50/(T2-T1) The concept assumes the calculation of the index as well as benzene, phenol, and catechof-ináuced inhibition of test cultures growth f(T2-T1,) in T2-T1, interval which corresponds in our experiment to the logarithmic phase of control culture growth. f(T2-T1,) was proved to remain in linear relation to the initial concentration of the investigated substances in culture medium. Also, it was found that the values of EC50/(T2-T1), calculated by probit methods, are characterized by confidence intervals comparable to those determined for EC50/96 and EC50/Tmax (the indexes were determined at hour 96 and Tmax, respectively)
This study continues our investigations concerning the interaction of phenol, catechol, 2,4-dichlorophenol (2,4-DCP), 2,4,5-trichlorophenol (2,4,5-TCP) and 2,4-dimethylphenol (2,4-DMP) with human erythrocytes. We focus on the effects of these compounds on erythrocyte membrane fluidity, as well as on their impact on membrane proteins. The fluorimetric method and fluorescent probes (ANS, DPH and TMA-DPH) were used to estimate the fluidity of erythrocyte membranes. SDS-gel electrophoresis was carried out to separate the proteins of the cell membrane. Additionally, an analysis of disturbances in size and shape of the erythrocytes by the application of the methods of flow cytometry and microscopic examination was performed. It was observed that phenol derivatives like 2,4-DCP, 2,4,5-TCP, 2,4-DMP and catechol induced changes in membrane fluidity and perturbations in the content of a cell’s membrane proteins. Changes in the level of spectrin, band 3 protein and low molecular weight proteins were also noted. Using three fluorescent probes we observed different changes in membrane fluidity on its different layers, depending on the structure and the concentration of the compound used. The application of flow cytometry and microscopic technique also demonstrated disturbances in the size and shape of erythrocytes. We concluded that chlorophenols induced more severe changes in erythrocyte membrane properties and phenol expressed the lowest toxicity.
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