1. Medical Chemistry, Graduate School of Medical Science Kyoto Prefectural University of Medicine 1-5 Shimogamo Hangicho Sakyo-ku, Kyoto 606-0823 Japan
2. Division of Organic Chemistry National Institute of Health Sciences 3-25-26 Tonomachi Kawasaki, Kanagawa 210-9501 Japan
3. Graduate School of Medical Life Science Yokohama City University 1-7-29 Suehiro-cho Tsurumi-ku, Yokohama 230-0045 Japan
4. Graduate School of Medicine, Dentistry and Pharmaceutical Sciences Okayama University 1-1-1 Tsushimanaka Kita-ku, Okayama 700-8530 Japan