1. Graduate School of Pharmaceutical Sciences, Osaka University, Yamada-oka 1-6, Suita, Osaka 565-0871, Japan
2. Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge CB2 1EW, U.K.
3. Japan Synchrotron Radiation Research Institute, 1-1-1 Kouto, Sayo-cho, Sayo-gun, Hyogo 679-5198, Japan
4. The Institute of Scientific and Industrial Research, Osaka University, Mihoga-oka, Ibaraki, Osaka 567-0047, Japan
5. Faculty of Pharmaceutical Sciences, Hokkaido University, Kuta-12, Nishi-6, Kita-ku, Sapporo 060-0812, Japan