1. Laboratory for Molecular Modeling, Division of Medicinal Chemistry and Natural Products, School of Pharmacy, CB# 7360, University of North Carolina, Chapel Hill, North Carolina 27599-7360, and Drug Metabolism and Pharmacokinetics, Mechanism and Extrapolation Technologies (MAI.A-3101), GlaxoSmithKline, 3030 Cornwallis Road, Research Triangle Park, North Carolina 27709