Interspecies quantitative structure–activity relationships (QSARs) for eco-toxicity screening of chemicals: the role of physicochemical properties

^$Presented at the 8^th International Symposium on Computational Methods in Toxicology and Pharmacology Integrating Internet Resources, CMTPI-2015, June 21-25, 2015, Chios, Greece.

Abstract

In addition to molecular structure profiles, descriptors based on physicochemical properties are useful for explaining the eco-toxicities of chemicals. In a previous study we reported that a criterion based on the difference between the partition coefficient (log P_OW) and distribution coefficient (log D) values of chemicals enabled us to identify aromatic amines and phenols for which interspecies relationships with strong correlations could be developed for fish–daphnid and algal–daphnid toxicities. The chemicals that met the log D-based criterion were expected to have similar toxicity mechanisms (related to membrane penetration). Here, we investigated the applicability of log D-based criteria to the eco-toxicity of other kinds of chemicals, including aliphatic compounds. At pH 10, use of a log P_OW – log D > 0 criterion and omission of outliers resulted in the selection of more than 100 chemicals whose acute fish toxicities or algal growth inhibition toxicities were almost equal to their acute daphnid toxicities. The advantage of log D-based criteria is that they allow for simple, rapid screening and prioritizing of chemicals. However, inorganic molecules and chemicals containing certain structural elements cannot be evaluated, because calculated log D values are unavailable.

Keywords:

• interspecies QSAR
• aquatic toxicity
• log D-based criterion
• pH
• structural alerts (SAs)

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Corrigendum

Acknowledgements

The authors thank Drs N. Tatarazako and T. I. Hayashi at the Center for Environmental Risk Research, NIES, Japan, for helpful discussions about the eco-toxicity data for each endpoint.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

^$ Presented at the 8^th International Symposium on Computational Methods in Toxicology and Pharmacology Integrating Internet Resources, CMTPI-2015, June 21-25, 2015, Chios, Greece.