QUANTITATIVE STRUCTURE-ACTIVITY RELATIONSHIPS FOR THE TOXICITY OF NITROBENZENES TO TETRAHYMENA THERMOPHILA

ABSTRACT

In this study IGC₅₀ (50% inhibitory growth concentration) values of 26 nitrobenzenes were determined for population growth endpoint of Tetrahymena thermophila. The toxicity order of the observed compounds has been found as follows: dinitro compounds>mononitro compounds; dichloronitrobenzenes>monochloronitrobenzenes; and meta-substituted nitrobenzenes > ortho-/para-substituted nitrobenzenes (NT, NPh, NAnis) except for the dinitrobenzenes and nitroanilines (DNB, NAn). Quantitative structure activity relationships (QSARs) were developed using log of the inverse of the IGC₅₀ in mole liter as the dependent variable and six molecular descriptors—log P, ¹ X ^v, I, ¹ Ka, Σσ⁻ and E _LUMO as the independent variables. Through multiplicate regression analysis, one best equation was obtained:

The equation was used to estimate IGC₅₀ for seven analogues.

Keywords:

• Tetrahymena thermophila
• Nitrobenzenes
• QSARs

Acknowledgments