Acute to chronic estimation of Daphnia magna toxicity within the QSAAR framework^*

* Presented at the 17th International Conference on QSAR in Environmental and Health Sciences (QSAR 2016), 13–17 June 2016, Miami Beach, FL, USA.

Abstract

We constructed models for acute to chronic estimation of the Daphnia magna reproductive toxicities of chemical substances from their Daphnia magna acute immobilization toxicities. The models combined the acute toxicities with structural and physicochemical descriptors. We used multiregression analysis and selected the descriptors for the models by means of a genetic algorithm. Of the best 100 models (as indicated by the lack of fit score), 90% included the following descriptors: acute toxicity (i.e. an activity parameter), distribution coefficient (log D) and structural indicator variables that indicate the presence of –NH₂ attached to aromatic carbon and the presence of a chlorine atom. We compared the predictive abilities of five of these quantitative structure–activity–activity relationship (QSAAR) acute to chronic estimation models with the predictive ability of a simple linear regression model. The comparison revealed that inclusion of structural and physicochemical descriptors such as those in QSAAR models can improve models for extrapolation from acute to chronic toxicity. Our results also provide a QSAAR framework that is expected to be useful for the further development of chronic toxicity estimation models.

Keywords:

• Daphnia magna reproduction toxicity
• Daphnia magna acute immobilization toxicity
• QSAAR
• structural indicator variable
• log D
• acute to chronic estimation (ACE)

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Corrigendum

Acknowledgement

We thank Mr. K. Hasunuma at Mizuho Information & Research Institute, Inc. for advice on constructing the toxicity prediction models.

Notes

* Presented at the 17th International Conference on QSAR in Environmental and Health Sciences (QSAR 2016), 13–17 June 2016, Miami Beach, FL, USA.