1. Kobe Pharmaceutical University Motoyamakita, Higashinada Kobe 658-8558 Japan
2. Faculty of Molecular Chemistry and Engineering Kyoto Institute of Technology Goshokaido-cho, Matsugasaki, Sakyo-ku Kyoto 606-8585 Japan
3. Department of Pharmaceutical Chemistry Kyoto Pharmaceutical University Misasagi-Nakauchi-cho, Yamashina-ku Kyoto 607-8414 Japan