1. Laboratory of Medicinal Chemistry, Center for Cancer Research, National Cancer Institute, National Insitutes of Health, Frederick, Maryland 21702, Protein Chemistry Laboratory, Advanced Technology Program, SAIC—Frederick, Frederick, Maryland 21702, Urologic Oncology Branch, Center for Cancer Research, National Cancer Institute, National Institutes of Health, Bethesda, Maryland 20892, and Data Management Services, Inc., NCI—Frederick, Frederick, Maryland 21702