title: Comparative quantitative structure-activity-activity relationships for toxicity to Tetrahymena pyriformis and Pimephales promelas.
abstract: An approach for predicting acute aquatic toxicity, in the form of a quantitative structure-activity-activity relationship (QSAAR), is described. This study assessed relative toxic effects to a fish, Pimephales promelas, and a ciliate, Tetrahymena pyriformis, and attempted to form relationships between them. A good agreement between toxic potencies (R2 = 0.754) was found for a chemically diverse dataset of 364 compounds, when using toxicity to the ciliate as a surrogate to that for fish. This relationship was extended by adding three theoretical structural descriptors of the molecules. The inclusion of these descriptors improved the relationship further (R2 = 0.824). The structural features that were found to improve the extrapolation between the toxicity to the two different species were related to the electron distribution of the carbon skeleton of the toxicant, its hydrogen-bonding ability, and its relative nitrogen content. Such a QSAAR approach provides a potential tool for predicting the toxicities of chemicals for environmental risk assessment and thus for reducing animal tests.
authors.affiliation: Department of Chemistry, University of Tartu, Tartu, Estonia.
authors.forename: Iiris
authors.initials: I
authors.lastname: Kahn
authors.forename: Uko
authors.initials: U
authors.lastname: Maran
authors.forename: Emilio
authors.initials: E
authors.lastname: Benfenati
authors.forename: Tatiana I
authors.initials: TI
authors.lastname: Netzeva
authors.forename: T Wayne
authors.initials: TW
authors.lastname: Schultz
authors.forename: Mark T D
authors.initials: MT
authors.lastname: Cronin
mesh_terms: D000818:Animals; D003530:Cyprinidae / Q000254:growth & development*; D004784:Environmental Monitoring / Q000379:methods; D007928:Lethal Dose 50; D008136:Longevity / Q000187:drug effects; D015394:Molecular Structure; D021281:Quantitative Structure-Activity Relationship; D013045:Species Specificity; D013769:Tetrahymena pyriformis / Q000187:drug effects* / Q000254:growth & development; D023382:Toxicity Tests, Acute / Q000379:methods*; D014873:Water Pollutants / Q000737:chemistry / Q000145:classification / Q000633:toxicity*
chemical_list: D014873:Water Pollutants