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Polar narcosis: Designing a suitable training set for QSAR studies Полный текст
1997
Ramos, Eñaut Urrestarazu | Vaes, Wouter H. J. | Verhaar, H. J. M. | Hermens, Joop L. M.
Substituted phenols, anilines, pyridines and mononitrobenzenes can be classified as polar narcotics. These chemicals differ from non-polar narcotic compounds not only in their toxic potency (normalized by log Kₒw), but also in their Fish Acute Toxicity Syndrome profiles, together suggesting a different mode of action.For 97 polar narcotics, which are not ionized under physiological conditions, 11 physico-chemical and quantum-chemical descriptors were calculated. Using principal component analysis, 91 % of the total variance in this descriptor space could be explained by three principal components which were subsequently used as factors in a statistical design. Eleven compounds were selected based on a two-level full factorial design including three compounds near the center of the chemical domain (a 2³+3 design).QSARs were developed for both the design set and the whole set of 63 polar narcotics for which guppy and/or fathead minnow data were available in the literature. Both QSARs, based on partial least squares regression (3 latent variables), resulted in good models (R²=0.96 and Q²=0.82; R²=0.86 and Q²=0.83 respectively) and provided similar pseudo-regression coefficients. In addition, the model based on the design chemicals was able to predict the toxicity of the 63 compounds (R² =0.85).Models show that acute fish toxicity is determined by hydrophobicity, HOMO-LUMO energy gap and hydrogen-bond acceptor capacity.
Показать больше [+] Меньше [-]The difference in brown trout (Salmo trutta L.) blood composition from acidic and limed sites of two rivers in western Norway
1997
Galina, M.S. (Moscow State Univ. (Russian Federation). Faculty of Biology, Dept. of Hydrobiology)
Fish diet and mercury exposure in a riparian amazonian population
1997
Lebel, J. (Quebec Univ., Montreal (Canada). Centre pour l'Etude des Interactions Biologiques entre la Sante et l'Environnement) | Roulet, M. | Mergler, D. | Lucotte, M. | Larribe, F.
Ash from cereal and rape straw used for heat production: liming effect and contents of plant nutrients and heavy metals
1997
Sander, M.L. (Swedish Univ. of Agricultural Sciences, Uppsala (Sweden). Dept. of Ecology and Environmental Research) | Andren, O.
Effect of As on chlorophyll and protein contents and enzymic activities in greening maize tissues
1997
Jain, M. (Agricultural Univ., Indore (India). School of Biochemistry) | Gadre, R.
Effects of watershed liming on Picea rubens seedling biomass and nutrient element concentration
1997
Smallidge, P.J. (Frostburg State Univ., Frostburg, MD (USA). Dept. of Biology) | Leopold, D.J.
Effect of metal ions on the entomopathogenic nematode Heterorhabditis bacteriophora poinar (Nematoda: Heterorhabditidae) under laboratory conditions
1997
Jaworska, M. (Hugon Kollataj Academy of Agriculture, Cracow (Poland). Dept. of Entomology) | Gorczyca, A. | Sepiol, J. | Tomasik, P.
Soil lead levels in orchards and roadsides of mission Peninsula, Michigan
1997
Francek, M.A. (Central Michigan Univ., Mt. Pleasant, MI (USA). Dept. of Geography and Earth Science)
Principal forest dieback episodes in Northern Hardwoods: development of numeric indices of areal extent and severity
1997
Auclair, A.N.D. (Science and Policy Associates Inc., Washington, DC (USA).) | Eglinton, P.D. | Minnemeyer, S.L.
Tree bark as a bioindicator of air pollution in Navarra, Spain
1997
Santamaria, J.M. (Navarra Univ., Pamplona (Spain). Dept. of Chemistry and Soil Science) | Martin, A.