1. Graduate School of Pharmaceutical Sciences, Nagoya City University, 3-1 Tanabe-dori Mizuho-ku, Nagoya, Aichi 467-8603, Japan, Department of Biomolecular Science, Toho University, 2-2-1 Miyama, Funabashi, Chiba 247-8510, Japan, and the Division of Organic Chemistry, National Institute of Health Sciences, Setagaya, Tokyo 158-8501, Japan