1. Natural Products Support Group, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Laboratory of Proteomics and Analytical Technologies, Advanced Technology Program, SAIC-Frederick, Inc., NCI-Frederick, Frederick, Maryland 21702, Molecular Targets Laboratory, Center for Cancer Research, NCI-Frederick, Frederick, Maryland 21702, and Bioresources Development and Conservation Programme-Cameroon, Yaounde, Cameroon