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(T/MF173) Model performance of QSARs based on empirical topological and quantum chemical descriptors. Class specific descriptors and data quality. Thomsen, Marianne1, Carlsen, Lars1, Fauser, Patrik1, 1 ABSTRACT- Based on the notorious PCBs, the performance of selected empirical (EM) versus non-empirical and quantum chemical (NEM-QC) descriptors in multivariate QSARs have been evaluated. The informational content of the EM descriptors has been evaluated with respect to the physical understandable NEM-QM descriptors. Models for estimating key parameters for risk assessment have been developed, based on two-dimensional EM and three-dimensional NEM-QC descriptors, respectively. Besides statistical design and elimination of class specific variables, the quality of experimental data used for calibrating the model is important for the development of QSARs. In this study we used data from various sources found in the literature, and the results of this investigation shows the importance in handling uncertainty aspects of the results obtained by different laboratories and methods. The latter is crucial for the calibration and development of models with high robustness and predictive power. In spite of the simplicity of the two-dimensional descriptors, no evidence of lower predictive ability of the EM descriptors compared to the NEM-QC descriptors was observed. Key words: PCB, QSAR, empirical/non-empirical descriptors, class specific variables |
