Structure Requirements for 4-Aryl-4H-Chromenes as Apoptosis Inducers Using 3D QSAR Methods and Docking Studies

Abstract

Presently, a computational study based on the combinational use of 3D-quantitative structureactivity relationship analyses (QSAR) methods including both the comparative molecular field analysis (CoMFA) and comparative molecular similarity analysis (CoMSIA) approaches and molecule docking was conducted on a series of 124 types of 4-aryl-4H-chromenes of 24 diverse structural scaffolds as promising novel apoptosis inducers, with purpose to explore the requisite structural features influencing their activity of caspase-3 activation in human breast tumor cells. The obtained 3D-QSAR models exhibited proper reliability and predictivity, where the optimal comparative molecular field analysis and comparative molecular similarity analysis ones gave leave-one-out cross-validation coefficient Q² of 0.508 and 0.477, conventional cross-validation coefficient R²_ncv of 0.888 and 0.816 for the training set and predictive correlation coefficients R²_pre of 0.604 and 0.150 for the independent test set, respectively. Analyses of the derived contour maps reveal that steric substituents at positions 4, 9-13, 15 and 16 favour the apoptosis inducing activity and electron-withdrawing groups at 6 and 10 positions or electron-donating groups at position-7 enhance the activity. Further docking study validates that 4-aryl-4H-chromenes bind at the colchicine site of tubulin and several hydrogen bonds serve to stabilize the ligand-tubulin complex. These models and the derived information, would be of value for further exploration of the apoptosis inducing mechanism and the screening of novel potent chromene-based apoptosis inducers.