1. Natural Products Laboratory, Research Triangle Institute, P.O. Box 12194, Research Triangle Park, North Carolina 27709, Department of Chemistry, North Carolina Central University, Durham, North Carolina 27707, Jardin Botanico Nacional “Dr. Rafael Moscoso”, Santo Domingo, Dominican Republic, Bristol-Myers Squibb Pharmaceutical Research Institute, P.O. Box 4000, Princeton, New Jersey 08543, and Program for Collaborative Research in the Pharmaceutical Sciences and Department of Medicinal Chemistry and...