Contribution from the Department of Chemistry, Inha University, 253 Yonghyundong Namgu, Inchon 402-751, Korea, College of Environmental Science and Applied Chemistry (BK21), Kyunghee University, Kyungki 449-701, Korea, Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 388-1 Pungnap-2-dong, Songpa-gu, Seoul 138-736, Korea, and Research Institute of Labeling, FutureChem Co. Ltd., 388-1 Pungnap-2-dong, Songpa-gu, Seoul 138-736, Korea (At 2006-11-23)