1. Division of Biotechnology and Pharmaceutical Research, National Health Research Institutes, 35 Keyan Road, Zhunan, Miaoli County 350, Taiwan, ROC
2. Department of Chemistry, National Tsing Hua University, 101 Guangfu Road Sec. 2, Hsinchu 300, Taiwan, ROC
3. Department of Biological Science and Technology, National Chiao Tung University, 1001 University Road, Hsinchu 300, Taiwan, ROC
4. Department of Chemistry, Chung Yuan Christian University, 200 Zhongbei Road, Zhongli 320, Taiwan, ROC