1. Department of Chemistry, National Tsing Hua University, 101 Section 2, Kuang Fu Road, Hsinchu 30013, Taiwan
2. Institute of Atomic and Molecular Science, Academia Sinica, P. O. Box 23-166, Taipei 10617, Taiwan
3. Department of Medicinal and Applied Chemistry, Kaohsiung Medical University, Kaohsiung 80708, Taiwan