1. CoMFA Study of Piperidine Analogues of Cocaine at the Dopamine Transporter: Exploring the Binding Mode of the 3  -Substituent of the Piperidine Ring Using Pharmacophore-Based Flexible Alignment Hongbin Yuan, Alan P. Kozikowski, and Pavel A. Petukhov* Department of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, University of Illinois at Chicago J. Med. Chem. 2004, 47, 6137-6143

2. outline Goal: to develop a model of the dopamine transporter (DAT) using QSAR analysis of cocaine analogues –No crystal structure of the DAT is available, but many piperidine analogues of cocaine have been synthesized and evaluated for binding affinity –A highly predictive model for the DAT would facilitate development of therapeutics for cocaine abuse Methods –Training set of 36 compounds, test set of 6 compounds –Genetic Algorithm Similarity Program (GASP) used to generate pharmacophore by comparing known ligands for DAT –Comparative molecular field analysis (CoMFA) calculates steric and electrostatic field energies –Refined with Flexible Superposition (FlexS)

3. Cocaine and analogues

4. Flow chart training set

5. Top two pharmacophores DS = H-bond donor AS = H-bond acceptor site AA = H-bond acceptor atom

6. Quantitative predictions are accurate

7. Conclusions Two pharmacophore models suggest multiple binding modes for ligands Good fit when QSAR applied to test set of 6 compounds Predictive power for new potential therapeutics