Conventional topological indices only describe the connections among atoms, which makes them impossible to discriminate the chiral information. In this article chiral topological indices were obtained by extending A_m indices and molecular connectivity indices and implemented in QSAR studies on a group of N-alkylated 3-(3-hydroxyphenyl)-piperidines with different pharmacological activity between pairs of enantiomers. The mathematical model obtained by using extended topological indices was better than that of A_m indices and molecular connectivity indices. And the method of cross-correlation was performed, which showed that the selected variable possessed low correlation. The cross-validation was calculated, demonstrating that the model was steady. Furthermore, the satisfactory results were achieved by using the artificial neural network.

Key words: chiral A_m indices, chiral molecular connectivity indices, σreceptor, N-alkylated 3-(3-hydroxyphenyl)-piperidine,QSAR