Quantum chemical descriptors for estimating the acute toxicity of substituted benzenes to the guppy (Poecilia reticulata) and fathead minnow (Pimephales promelas)
In an attempt to develop quantitative structure activity relationships (QSAR) for acute toxicity across a relatively large and well defined chemical domain, a series of benzenes extracted from existing collections of toxicity data for guppies and fathead minnows were studied. The selection of compounds was based on prohibited substructural screens that represent inherently reactive electrophilic groups or other chemical functions known to induced particular toxic effects. The resultant correlation samples were comprised of 64 and 122 substituted benzenes tested on the guppy and fathead minnow, respectively. The QSAR analysis showed that the toxicodynamic component of the toxic potency is mainly related to the electrophilicity of the aromatic ring in terms of the maximal acceptor super delocalizability, A(max). By inclusion of A(max) as an additional variable into the generic log linear regression, the explained variance increased from 51% to 73% and from 67% to 83% for the guppy and fathead minnow data sets, respectively. The significance of A(max) is interpreted by the fact that it provides a crude differentiation between benzenes acting through different modes of toxic action. For the guppy sample, a significant 3 variable QSAR was derived, which employed both maximal acceptor and donor super delocalizabilities as electronic descriptors and provided a more definite quantitative separation for the benzene derivatives.
Bibliographic Reference: Article: Quantitative Structures - Activity Relationships
Record Number: 199610040 / Last updated on: 1996-02-16
Original language: en
Available languages: en