1. Graduate School of Pharmaceutical Sciences Osaka University 1-6, Yamada-oka, Suita Osaka 565-0871 Japan
2. A Laboratory of Organic Chemistry Gifu Pharmaceutical University 1-25-4-Daigaku-nishi Gifu 501-1196 Japan
3. Graduate School of Pharmaceutical Sciences The University of Tokyo Tokyo 113-0033 Japan
4. Graduate School of Medicine The University of Tokyo Tokyo 113-0033 Japan
5. Department of Life Science and Technology Tokyo Institute of Technology Kanagawa 226–8501 Japan
6. Graduate School of Advanced Science and Engineering Hiroshima University 1-4-1 Kagamiyama, Higashi-Hiroshima Hiroshima 739-8527 Japan