Prediction of the Fate of Organic Compounds in the Environment From Their Molecular Properties: A Review

Abstract

A comprehensive review of quantitative structure-activity relationships (QSAR) allowing the prediction of the fate of organic compounds in the environment from their molecular properties was done. The considered processes were water dissolution, dissociation, volatilization, retention on soils and sediments (mainly adsorption and desorption), degradation (biotic and abiotic), and absorption by plants. A total of 790 equations involving 686 structural molecular descriptors are reported to estimate 90 environmental parameters related to these processes. A significant number of equations was found for dissociation process (pKa), water dissolution or hydrophobic behavior (especially through the KOW parameter), adsorption to soils and biodegradation. A lack of QSAR was observed to estimate desorption or potential of transfer to water. Among the 686 molecular descriptors, five were found to be dominant in the 790 collected equations and the most generic ones: four quantum-chemical descriptors, the energy of the highest occupied molecular orbital (EHOMO) and the energy of the lowest unoccupied molecular orbital (ELUMO), polarizability (α) and dipole moment (μ), and one constitutional descriptor, the molecular weight. Keeping in mind that the combination of descriptors belonging to different categories (constitutional, topological, quantum-chemical) led to improve QSAR performances, these descriptors should be considered for the development of new QSAR, for further predictions of environmental parameters. This review also allows finding of the relevant QSAR equations to predict the fate of a wide diversity of compounds in the environment.

Dissipation of chlortetracycline in the aquatic environment: Characterization in terms of a generalized multiphase pseudo–zero‐order rate law

“…When these conditions are not met, the rate equations for the different speciation forms of the pollutant in Equations and become overall pseudo–second order, or overall pseudo–first order if the microorganism population is assumed constant. Such pseudo–first‐order kinetics would be consistent with the currently accepted models for the dissipation of organic pollutants in the environment that assume first‐order kinetics …”

“…Such pseudo-first-order kinetics would be consistent with the currently accepted models for the dissipation of organic pollutants in the environment that assume first-order kinetics. 28,29…”

Computing pKa Values in Different Solvents by Electrostatic Transformation

“…It is a physico-chemical key quantity to characterize and predict the behavior of such molecules [1][2][3] . The pK A governs solubility, volume of distribution and clearance of drug molecules [4][5][6][7][8] and the thermodynamics of metabolic reactions 9 .…”

In silico environmental chemical science: properties and processes from statistical and computational modelling

“…6 Prominent early examples are the Handbook of Chemical Property Estimation Methods compiled by Lyman et al, 11 and a similarly structured volume edited by Mackay and Boethling. 12 Since then, there has been a growing number of reviews and databases of QSARs, [13][14][15][16][17] comparative analyses of QSAR accuracy, [18][19][20] and efforts to codify methods of calibration and validation. [21][22][23][24][25] Many QSARs have been incorporated into soware that facilitates their use for property prediction.…”