Classification and Quantification of the Toxicity of Chemicals to Guppy, Fathead Minnow, and Rainbow Trout. Part 2. Polar Narcosis Mode of Action

Abstract

This paper is devoted to the classification of chemicals with polar narcosis Mode of Action (MOA) to guppy, fathead minnow and rainbow trout, and to creation of QSARs for toxicity prediction of such chemicals on the basis of physicochemical descriptors calculated by the HYBOT program. More than 85% of all chemicals were correctly classified (polar narcosis/other MOA, polar narcosis/baseline toxicity (nonpolar narcosis), polar narcosis þ baseline toxicity/other MOA) on the basis of structural similarity. Regression equations with good statistical criteria using HYBOT physicochemical descriptors were obtained for the toxicity of chemicals with polar narcosis MOA.Comparison of those equations with the equations for baseline toxicity permitted estimation of the essential contribution of baseline toxicity to the toxicity of all chemicals with polar narcosis MOA. The ratio of polar and nonpolar contributions depends on hydrophobity. Such behavior can be related to the increased opportunity of a hydrophobic chemical to move in all directions in the hydrocarbon-like interior of the membrane.

QSAR models of the inhalation toxicity of organic compounds

“…We recently carried out a detailed QSAR study of the toxicity of organic compounds with respect to guppies, minnows, rainbow trout [10,11], and Daphnia magna [12]. QSAR models for CC with nonspecific toxicity that were based on experimental distribution parameters were replaced successfully by reliable predictive models based on physicochemical descriptors calculated by the program HYBOT.…”

Investigation on modes of toxic action to rats based on aliphatic and aromatic compounds and comparison with fish toxicity based on exposure routes

“…The concentration required to kill 50% of fish within 96 h, were taken from Raevsky et al (2008Raevsky et al ( , 2009. They confirmed the wellknown good correlations of toxicity between the three fish species and mentioned that the quality of the experimental data was not perfect for fathead minnow and rainbow trout.…”

Discrimination of excess toxicity from narcotic effect: Influence of species sensitivity and bioconcentration on the classification of modes of action

“…Table 2 also lists linear regression equations between log K OW and the toxicity to four species for phenols and anilines with alkyl, fluorine and chlorine substituents. The mode of action for these phenols and anilines is widely recognized as that of less inert compounds (Verhaar et al, 1992;Raevsky et al, 2009). Fig.…”

“…The LC 50 values to guppy (Poecilia reticulata) and rainbow trout (Oncorhynchus mykiss) were taken from Raevsky et al (2008) and Raevsky et al (2009). The LC 50 values to fathead minnow (Pimephales promelas) were taken from Russom et al (1997), Yuan et al (2007), Papa et al (2005), Eroglu et al (2007), and Raevsky et al (2008) and Raevsky et al (2009) respectively. These LC 50 values to fathead minnow were averaged and are presented in Table S1 of Supplementary material.…”