1. Division of Mass Spectrometry, Korea Basic Science Institute, Ochang-Myun, Cheongwon-Gun 363-883, Republic of Korea, Daejeon-KRIBB-FHCRC Research Cooperation Center, KRIBB, Yuseong-gu, Daejeon 305-806, Republic of Korea, Department of Chemistry, Hannam University, Daejeon 306-791, Republic of Korea, Department of Chemistry, Yonsei University, Seoul 120-749, Republic of Korea, and GRAST, Chungnam National University, Daejeon 305-764, Republic of Korea