1. Cancer Research Institute and Department of Chemistry and Biochemistry, Arizona State University, P.O. Box 872404, Tempe, Arizona 85287-2404, Screening Technologies Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, National Cancer Institute at Frederick, National Institutes of Health, Frederick, Maryland 21702, University of Bradford, Cancer Research Unit, West Yorkshire BD7 1DP, United Kingdom, and Science Applications International Corp., National Cancer Institute...