QSAR analysis of substituted bis[(acridine-4-carboxamide)propyl]methylamines using optimized block-wise variable combination by particle swarm optimization for partial least squares modeling

In the current work, we employed optimized block-wise variable combination (OBVC) by particle swarm optimization (PSO) based on partial least squares (PLS) modeling for variable combination and compared it to the traditional methods. It has been demonstrated that the modified PSO is a useful tool for searching optimized variable combination. Quantitative structure-activity relationship (QSAR) model has been formulated for a set of DNA binding topoisomerase (topo) (substituted bis[(acridine-4-carboxamide)propyl]methylamines) on murine Lewis lung carcinoma (LLc) cells. The spatial descriptors especially Jurs descriptors play important roles in predicting the compound's inhibitory activity to murine LLc cells, and polar interactions are the principal binding strength between compounds and murine LLc cells. In addition, rotatable bonds in molecules and molar refractivity of the compounds will markedly affect the compounds' inhibitory activity.