1. Department of Medicinal Chemistry and Pharmacognosy, School of Pharmacy and Pharmacal Sciences, Purdue University, West Lafayette, IN 47907
2. Current address: Faculty of Pharmacy, Jordan University of Science and Technology, Irbid, Jordan
3. Northern Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, Peoria, IL 61604
4. Lilly Research Laboratories, Greenfield Laboratories, P.O. Box 708, Greenfield, IN 46140