1. Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, and Division of Hematology and Oncology, Department of Internal Medicine, College of Medicine and Public Health, The Ohio State University, Columbus, Ohio 43210, Isolation and Structure Elucidation Group, Analytical Research and Development, Pharmaceutical Research Institute, Bristol-Myers Squibb, One Squibb Drive, New Brunswick, New Jersey 08903, and Nature's Sunshine Products, Inc., 1655 North Main Street, Spanish Fork, Utah 84660