1. Fuji Nihon Seito Corporation, 1-4-10 Shimizuseikai, Shizuoka City, Shizuoka 424-8737, Japan, Department of Pharmaco-Biochemistry and 21COE, School of Pharmaceutical Sciences, University of Shizuoka, 52-1 Yada, Shizuoka City, Shizuoka 422-8526, Japan