Optimisation of correlation weights of SMILES invariants for modelling oral quail toxicity.

The SMILES (simplified molecular input line entry system) nomenclature was used to elucidate the molecular structure in constructing the quantitative structure-property/activity relationships (QSPR/QSAR) for predicting quail toxicity after oral exposure. The presence of chemical elements in different electronic states (e.g., C, c, O, o, Cl, Br, etc.) and of different covalent bonds (i.e., -,=, and #) was used as local invariants. Combinations of different presence/absence codes for local features of the SMILES were used as global invariants. The statistical characteristics of this model are n=97, r(2)=0.755, s=0.445, F=293 (training set); n=18, r(2)=0.731, s=0.587, F=43 (test set).