1. Amino Up Chemical Company, Ltd., High Tech Hill Shin-ei, 363-32 Kiyota, Sapporo 004-0839, Japan; Institute of Natural Medicine, University of Toyama, 2630 Sugitani, Toyama 930-0194, Japan; and Usaien Pharmaceutical Company, Ltd., 1-4-6 Zaimoku, Saga 840-0055, Japan