Affiliation: | 1. Laboratory of Chemistry, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland 20205 USA;2. Laboratory of Bioorganic Chemistry, National Institute of Arthritis, Diabetes, and Digestive and Kidney Diseases, NIH, Bethesda, Maryland 20205 USA;3. Field Museum of Natural History, Chicago, Illinois 60605 USA;4. Botanical Museum, Harvard University, Cambridge, Massachusetts 12138 USA |