Structure-activity relationship of the radical scavenging activities of some natural antioxidants based on the graph of atomic orbitals

The quantitative activity relationships (QSARs) of the radical scavenging activities of 96 natural anti-oxidants based on the graph of atomic orbitals by CORAL software. The QSAR models are developed with the representation of the molecular structure by the Simplified Molecular Input-Line Entry System (SMILES) and the Monte Carlo optimization was used for calculation of the correlation weights of optimal SMILES based descriptors. The data set was randomly distributed three times into the training, invisible training, calibration and validation set was examined. The R-2 values of the validation set for splits 1 to 3 were 0.966, 0.921, and 0.886 respectively. These models are established using only SMILES information, without any information on physicochemical parameters, the quantum mechanics descriptors, or 3D descriptors of the antioxidant structures. The obtained results indicated that the proposed QSAR models can be successfully used for predictions of the radical scavenging activities of new natural and synthetic antioxidants. (C) 2019 Elsevier B.V. All rights reserved.