1. DSM Pharma Chemicals, PMB 150, 9650 Strickland Road Suite 103, Raleigh, North Carolina 27615, U.S.A., DSM Pharma Chemicals, 1421 Kalamazoo Street, South Haven, Michigan 49090, U.S.A., and Department of Chemistry, Colorado State University, Fort Collins, Colorado 80523, U.S.A.