1. Graduate
School of Pharmaceutical Sciences, The University of Tokyo, Bunkyo-ku, Tokyo 113-0033, Japan
2. Faculty
of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima 770-8514, Japan
3. National Institute of Infectious Diseases, Shinjuku-ku, Tokyo 162-8640, Japan
4. Department
of Chemistry, University of British Columbia, Vancouver, British Columbia V6T 1Z1, Canada