1. Natural Products Support Group, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Molecular Target Screening Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, DTP Tumor Hypoxia Laboratory, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Screening Technologies Branch, Developmental Therapeutics Program, Division of Cancer Treatment and Diagnosis, NCI-Frederick, Frederick, Maryland 21702, and Department of Medicinal Chemistry and Molecular Pharmacology,...