1. Department of Chemistry and Physics, Indiana State University, Terre Haute, Indiana 47809, United States
2. Department of Chemistry, Brandeis University MS 015, Waltham, Massachusetts 02453, United States
3. Neurobiology Laboratory, National Institute of Environmental Health Sciences, NIH/DHHS, Research Triangle Park, North Carolina 27709, United States
4. Department of Pharmacology and Physiology, Georgetown University, Washington, D.C. 20057, United States
5. Poisonous Plant Research Laboratory, United States Department of Agriculture, Agricultural Research Service, Logan, Utah 84341, United States