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Main Title QSAR Approach for Estimating the Aquatic Toxicity of Soft Electrophiles (QSAR for Soft Electrophiles).
Author Veith, G. D. ; Mekenyan., O. G. ;
CORP Author Environmental Research Lab.-Duluth, MN. ;Wisconsin Univ.-Superior. Lake Superior Research Inst.
Publisher c1993
Year Published 1993
Report Number EPA/600/J-94/178;
Stock Number PB94-163573
Additional Subjects Water pollution effects(Animals) ; Toxicity ; Fishes ; Benzenes ; Phenols ; Anilines ; Narcotics ; Molecular energy levels ; Tables(Data) ; Reprint ; QSAR(Quantitative Structure-Activity Relationship) ; Soft nucleophiles ; Soft electrophiles
Library Call Number Additional Info Location Last
NTIS  PB94-163573 Some EPA libraries have a fiche copy filed under the call number shown. 07/26/2022
Collation 10p
This work demonstrated that descriptors of soft electrophilicity for aromatic chemicals such as average superdelocalizability and LUMO energy could be used together with the hydrophobicity descriptor, log P, to explain the variation of acute toxicity of substituted benzenes, phenols, and anilines to fish. For proelectrophiles, the structure-toxicity relationships accurately predict toxicity when the stereoelectronic parameters were computed for the metabolic activation products. The QSAR for acute toxicity using these molecular descriptors defines a toxicity plane which includes several modes of toxic action. Type (I) narcotics are chemicals located in the region of low reactivity where toxicity varies with hydrophobicity alone. Type (II) narcotics are more toxic than type (I) narcotics at similar values of log P, and the increase can be explained by stronger electronic interactions with cellular soft nucleophiles. Highly reactive soft electrophiles which have dissociating protons such as 2,4-dinitrophenol produce symptoms of respiratory uncouplers. Those without dissociating protons produce symptoms of reactive toxicity consistent with covalent binding. (Copyright (c) 1993 VCH Verlagsgesellschaft mbH.)