1. Department of Chemistry, University of New Mexico, Albuquerque, New Mexico 87131, Center for Advanced Research in Biotechnology, University of Maryland Biotechnology Institute, Rockville, Maryland 20850, Department of Horticulture, Purdue University, West Lafayette, Indiana 47907, and Molecular Structure Unit Laboratory of Neurotoxicology, National Institute of Mental Health, National Institutes of Health, Bethesda, Maryland 20892