Drug Discovery Department, Research & Development Division, PharmaDesign, Inc,, Hatchobori 2-19-8, Chuo-ku, Tokyo, Japan. sugaya@pharmadesign.co.jp|Drug Discovery Department, Research & Development Division, PharmaDesign, Inc,, Hatchobori 2-19-8, Chuo-ku, Tokyo, Japan. sugaya@pharmadesign.co.jp