1. Department of Chemistry, National Changhua University of Education, 1 Jin-De Road, Changhua City 50007, Taiwan
2. School of Post-baccalaureate Chinese Medicine, China Medical University, 91, Hsueh-Shih Road, Taichung 40424, Taiwan
3. Department of Chemistry, University of Wisconsin-Platteville, 1 University Plaza, Platteville, Wisconsin 53818-3099, United States