Abstract: The aim of this study was to determine which descriptor best parametrized the electrophilicity of aromatic compounds with regard to their acute toxicity. To achieve this, toxicity data for 203 substituted aromatic compounds containing a nitro- or cyano group were evaluated in the 40-h Tetrahymena pyriformis population growth impairment assay. Quantitative ...

Abstract: The modeling of aquatic toxic potency of 35 diesters tested using the static Tetrahymena pyriformis population growth inhibition assay has been investigated. Toxicity was correlated with a number of structural patterns. including the bond type at the carbon atom adjacent to the carbonyl group. The less toxic saturated and non-α,β-unsaturated diesters are ...

Abstract: We report methods to predict the intrinsic aqueous solubility of crystalline organic molecules from two different thermodynamic cycles. We find that direct computation of solubility, via ab initio calculation of thermodynamic quantities at an affordable level of theory, cannot deliver the required accuracy. Therefore, we have turned to,a mixture of direct ...

Abstract: A response-plane has been developed with Tetrahymena pyriformis population growth impairment toxicity data [log 1/50% growth inhibitory concentration (IGC50)], the 1-octanol/water partition coefficient (log Kow), and the energy of the lowest unoccupied molecular orbital (Elumo). A statistically robust plane [log 1/IGC50 = 0.530 (log Kow) -0.890 (Elumo) -0.271, ...

Abstract: Hydrophobic- and electrophilic-dependent structure-toxicity relationships were developed and compared for several mechanisms of toxic action. Potency data included values from the 96-h Pimephales promelas mortality assay, the 40-h Tetrahymena pyriformis population growth inhibition assay, and the 15-min Vibrio fischeri luminescence inhibition assay. In addition ...

Abstract: A series of 37 aliphatic and aromatic sulfur-containing compounds were evaluated in 2-day Tetrahymena pyriformis population growth impairment assay. The results indicate that, except for select compounds, the in-ring sulfur-containing compounds, sulfates, sulfites, thiols, sulfones, and sulfoxides model as neutral and noncovalent-reacting narcotics. Abiotic ...

Abstract: A diverse series of amides were evaluated for aquatic toxicity (IGC(50)) assessed in the Tetrahymena pyriformis population growth impairment assay and for reactivity (EC(50)) with the model soft nucleophile thiol in the form of the cysteine residue of the tripeptide glutathione. All alkylamides along with some halo-substituted amides are well predicted by the ...