3D-QSAR Studies of Natural Steroidal Saponins as Anticancer Agents in Human Nasopharyngeal Carcinoma Epithelial Cells

Three-dimensional quantitative structure-activity relationship (3D-QSAR) studies were carried out on a series of structurally related steroidal saponins isolated from Paris polyphylla var. yunnanensis in order to determine the structural properties required for their cytotoxic effect on human nasopharyngeal carcinoma epithelial (CNE) cells. The comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) models using twenty-five compounds in the training set gave the cross-validated correlation coefficients r2cv values of 0.667 and 0.686, non-cross-validated correlation coefficients r2 values of 0.985 and 0.976, and predicted correction coefficients r2pred values of 0.887 and 0.740, respectively, indicating that both methods have significant predictive capability. The contour maps generated by the CoMFA and CoMSIA models were used to identify the key structural requirements responsible for the biological activity. The findings of these molecular modeling studies can serve as a useful guide for future rational design of potential agents with better anti-CNE activity.