1. Graduate
School of Pharmaceutical Sciences, the University of Tokyo, 7-3-1 Hongo Bunkyo-ku, Tokyo 113-0033, Japan
2. Institute of Microbial Chemistry, Tokyo, Kamiosaki 3-14-23, Shinagawa-ku, Tokyo 141-0021, Japan
3. ACT-C, Japan Science
and Technology Agency, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan