PARENT SESSION
83 - QSAR Approaches
8:00 AM to 6:30 PM, Wednesday, 15 May 2002
Exhibition Area

(83-05) Mechanism of action based QSARs for the toxicity of phenols to Tetrahymena pyriformis.

Aptula, Aynur^*,1, Cronin, Mark², Duffy, Judith², Fara, Daniel³, Netzeva, Tatiana², Karelson, Mati³, Maran, Uko³, Schultz, Terry⁴, Schüürmann, Gerrit¹, ¹ UFZ Centre for Environmental Research, Leipzig, Germany² Liverpool John Moores University, Liverpool, England³ University of Tartu, Tartu, Estonia⁴ The University of Tennessee, Knoxville, TN

ABSTRACT- The aim of this study was to develop mechanism-based quantitative structure-activity relationships (QSARs) for the toxicity to Tetrahymena pyriformis of 221 phenols. The phenols had previously been classified into four mechanisms of action: polar narcotics, weak acid respiratory uncouplers, pro-electrophiles and soft electrophiles. Physico-chemical descriptors were calculated from a number of approaches including the TSAR molecular spreadsheet and the CODESSA software. These included descriptors for the hydrophobic, steric and electronic properties of the compounds, and as well as topological indices. Multilinear regression leads to class-specific QSARs that differ in both the relevant descriptors and the statistical performance. [This work was supported in part by the European Union IMAGETOX Research Training Network (HPRN-CT- 1999-00015).]

Key words: QSAR, Tetrahymena pyriformis, phenol, mechanism of toxic action