30-Modelling and Prediction by WHIM Descriptors. Part 8. Toxicity and Physico-chemical Properties of Environmental Priority Chemicals by 2D-TI and 3D-WHIM Descriptors

Abstract

In environmental and ecotoxicological problems, the need for more general predictive models is one of the aims of the science. To reach this objective, the models, even if capable of producing more approximate values, must be applicable to the huge number of chemicals put on the market that are discharged in the environment, at least for setting priority lists among potentially hazardous substances.

Theoretically, the problem is not insurmountable if one assumes that all properties of a chemical (physico-chemical, biological, toxicological) are related to its structural features.

The challenge is to describe and represent, on a quantitative basis, all molecular structural features in order to use them as independent variables in a quantitative structure-activity model.

In this paper, structural, topological, and 3D-WHIM descriptors are used for modelling toxicological and physico-chemical properties of compounds that are included in the European Union's so-called “List I” of priority chemicals dangerous for the aquatic environment.

Key Words:

• Topological descriptors
• WHIM descriptors
• 3D-QSAR
• variable selection
• hydrophilicity index
• water quality objectives (WQO)