1. Division of Chemistry, Department of Medical Sciences, Faculty of Medicine, University of Miyazaki, 5200 Kihara, Kiyotake, Miyazaki 889-1692, Japan
2. Shonan Laboratory, Corporate R&D Headquarters, Otsuka Chemical Co., Ltd., 2Chome26-1, Muraokahigashi, Fujisawa, Kanagawa 251-8555, Japan
3. Laboratory of Chemical Biology and State Key Laboratory of Rare Earth Resource Utilization, Changchun Institute of Applied Chemistry, Chinese Academy of Science, Changchun, Jilin 130022, P. R. China
4. School of Applied Chemistry and Engineering, University of Science and Technology of China, Hefei, Anhui 230026, P. R. China