1. Natural Products Laboratory, School of Pharmacy, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599-7360, Hoshi University, 2-4-41 Ebara, Shinagawa, Tokyo 158-0098, Japan, AndroScience Corporation, 11175 Flintkote Avenue, Suite F, San Diego, California 92121, and George Whipple Laboratory for Cancer Research, Departments of Pathology, Urology and Radiation Oncology, University of Rochester Medical Center, 601 Elmwood Avenue, Box 626, Rochester, New York 14642