1. Department of Chemistry, Texas A&M University, P.O. Box 30012, College Station, Texas 77842-3012, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, New York 10461, Eli Lilly & Company, Lilly Biotechnology Center, 10300 Campus Point Drive, Suite 200, San Diego, California 92121, and Department of Pharmaceutical Chemistry, University of California, San Francisco, 1700 Fourth Street, San Francisco, California 94158-2330