Institution: | a Department of Chemistry, Hankuk University of Foreign Studies, Yongin 449-791, Korea b Imagene Co. Ltd, Biotechnology Incubating Center, Seoul National University, Seoul 151-742, South Korea c Department of Molecular Science and Technology, Ajou University, Suwon 442-749, South Korea d Department of Chemistry, Sogang University, Seoul 121-742, South Korea |