Building up a QSAR model for toxicity toward Tetrahymena pyriformis by the Monte Carlo method: A case of benzene derivatives

- The Monte Carlo method is used to estimate toxic potential of molecular fragments.
- The toxic potential of molecular fragments is used to calculate molecular descriptors.
- The descriptors well correlated with fish toxicity.
- The calculations were carried out with CORAL software.
- The statistical quality of these models is good.

Data on toxicity toward Tetrahymena pyriformis is indicator of applicability of a substance in ecologic and pharmaceutical aspects. Quantitative structure-activity relationships (QSARs) between the molecular structure of benzene derivatives and toxicity toward T. pyriformis (expressed as the negative logarithms of the population growth inhibition dose, mmol/L) are established. The available data were randomly distributed three times into the visible training and calibration sets, and invisible validation sets. The statistical characteristics for the validation set are the following: r2 = 0.8179 and s = 0.338 (first distribution); r2 = 0.8682 and s = 0.341 (second distribution); r2 = 0.8435 and s = 0.323 (third distribution). These models are built up using only information on the molecular structure: no data on physicochemical parameters, 3D features of the molecular structure and quantum mechanics descriptors are involved in the modeling process.