1. Faculty of Pharmaceutical Sciences, Center for Research and Education on Drug Discovery, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan, School of Pharmaceutical Sciences, University of Shizuoka, 52-1, Yata, Suruga-ku, Shizuoka 422-8526, Japan, PRISM BioLab Co., Ltd., 4259-3, Nagatsuta-cho, Midori-ku, Yokohama 226-8510, Japan, and D.D.P. Corporation, 1097-3, Kashiya, Kannami-cho, Shizuoka 419-0112, Japan