1. Department of Chemistry Willard H. Dow Laboratories University of Michigan Ann Arbor Michigan 48109 USA
2. Helen Scientific Research and Technological Development Co. Ltd Ho Chi Minh City Vietnam
3. Centre de Biophysique Moléculaire CNRS UPR 4301 Rue Charles Sadron 45071 Orléans Cedex 2 France
4. College of Pharmacy and Michigan Medicine University of Michigan Ann Arbor Michigan 48109 USA