1. Laboratory of Medicinal and Pharmaceutical Chemistry; Gifu Pharmaceutical University; Gifu 501-1196 Japan
2. Laboratory of Pharmaceutical Chemistry, Faculty of Pharmaceutical Sciences; Okayama University; Kita-ku Okayama 700-8530 Japan
3. Research Core for Interdisciplinary Sciences; Okayama University; Kita-ku Okayama 700-8530 Japan
4. Department of Chemistry, Faculty of Science; Okayama University; Kita-ku Okayama 700-8530 Japan