1. The Ui Laboratory, the Institute of Physical and Chemical Research, Hirosawa 2-1, Wako-shi 351-0198, Japan
2. Tokushima Research Institute, Otsuka Pharmaceutical Co., Ltd., Kagasuno 463-10, Kawauchi-cho, Tokushima 771-0130, Japan
3. Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, University of Tokyo, Hongo 7-3-1, Bunkyo-ku, Tokyo 113-0033, Japan
4. The Tokyo Metropolitan Institute of Medical Science, Honkomagome 3-18-22, Bunkyo-ku, Tokyo 113-8613, Japan