1. (a) On leave from Shionogi & Co. Ltd., Discovery Research Laboratories I, 12-4, Sagisu, 5-Chome, Fukushima-Ku, Osaka, 553-0002, Japan.
2. (b) Current address: Department of Chemistry, Colorado State University, Fort Collins, CO 80523-1872.
3. Ueber die Bohne von Calabar