Assessment of baseline toxicity of mono-cyclic aromatic compounds by pseudomonas initial oxygen uptake assay

Abstract

The objective of this study was to develop quantitative structure-activity relationships (QSARs) for the toxicity of mono-cyclic aromatic compounds in the Pseudomonas putida initial oxygen uptake assay. The QSARs were developed using response-surface based on descriptors for chemical hydrophobicity (log \hspace{0.167em} P) and electrophilicity (LUMO). The model

( \pm 0.011)log \hspace{0.167em} P - 0.389 {\rm ( \pm 0.013)LUMO - 2.131( \pm 0.031)} ; n = 155, r^{2} = 0.941,

s = 0.119, F = 1206 led us to conclude that the polar and non-polar narcotics were statistically indistinguishable. Pentafluorophenol, pentachlorophenol and most dinitrophenols classified as weak acid respiratory uncouplers in literature fit well into this model when they were treated as their corresponding phenoxides. This latter result suggests that the action mechanism of these phenols should be reevaluated.

Keywords:

• Narcosis
• Uncoupling
• Baseline toxicity
• QSAR
• Toxicokinetic

Acknowledgements

The authors would like to thank the National Science Council of the Republic of China for financially supporting this research under Contract No. NSC 92-2113-M-006-009 and 93-2113-M-006-009.