1. College of Pharmacy and Nutrition and Departments of Chemistry and Biochemistry, University of Saskatchewan, Saskatoon, Saskatchewan S7N 5C9, Canada, Department of Medical Chemistry, University Medical School of Pécs, H-7624 Pécs, Hungary, Department of Pharmacology, University of Alberta, Edmonton, Alberta T6G 2H7, Canada, and Rega Institute for Medical Research, Katholieke Universiteit Leuven, B-3000 Leuven, Belgium