1. Graduate Institute of Pharmaceutical Chemistry, College of Pharmacy, China Medical University, Taichung 404, Taiwan, Graduate Institute of Natural Products, College of Medicine, Chang Gung University, Taoyuan 333, Taiwan, Institute of Biological Chemistry, Academia Sinica, Taipei 115, Taiwan, Genomics Research Center, Academia Sinica, Taipei 115, Taiwan, and Department of Life Sciences, National Chung-Hsing University, Taichung 402, Taiwan, Republic of China