1. Drug Discovery Research Center, Taiho Pharmaceutical Co. Ltd., Okubo 3, Tsukuba, Ibaraki 300-2611, Japan
2. Laboratory
of Pharmaceutical and Medicinal Chemistry, Gifu Pharmaceutical University, 1-25-4 Daigaku-nishi, Gifu 501-1196, Japan
3. Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo
060-0812, Japan