RESUMO
Four descriptors (Molecular weight, log(Pow), hardness and free energy of solvation) were selected to predict, on a training set of heterogeneous chemical compounds, the fish acute toxicity. The data were extracted from 523 notification files of new chemicals stored at the French Department of the Environment. The selection of the descriptors was carried out by using a statistical technique coupling OLS regression and genetic algorithm. The limits of validity for the final equation are discussed by comparing the actual and predicted activities on several compounds.
Assuntos
Algoritmos , Peixes , Xenobióticos/toxicidade , Animais , Previsões , Valor Preditivo dos Testes , Xenobióticos/químicaRESUMO
Two descriptors (log(P(ow)), 'hardness') were selected to predict the Daphnia acute toxicity of a training set of heterogeneous chemical compounds. The data were extracted from 523 notification files about new chemicals stored at the French Department of Environment. The selection of the descriptors was carried out using a statistical method coupling ordinary least square (OLS) regression and genetic algorithm (GA). The validity limits for the final equation are discussed by comparing the actual and predicted activities of several compounds. The study points out the interest of the 'hardness' parameter for quantitative structure-activity relationships (QSAR) with a heterogeneous data set.
Assuntos
Daphnia , Modelos Genéticos , Modelos Teóricos , Testes de Toxicidade/estatística & dados numéricos , Poluentes Químicos da Água/toxicidade , Animais , Dano ao DNA , Relação Dose-Resposta a Droga , Previsões , Valores de Referência , Análise de Regressão , Medição de Risco , Relação Estrutura-Atividade , Água/químicaRESUMO
Free energies of solvation of chlorophenols were calculated in two solvents: water and n-hexadecane from the AMSOL program. These free energies of solvation are the sum of two terms: polarization free energies (delta GENP) and cavity, dispersion, solvent structure free energies (G degree CDS). This study shows, in the case of chlorophenols, that a direct relation exists between one of the two components for the calculation of free energy (G degree CDS) in water and n-hexadecane, and the ecotoxicity values for five biological systems. We point out the interest of using these new descriptors in QSAR study.