1. National Research Institute of Chinese Medicine, Taipei 112, Taiwan, Republic of China, School of Chinese Medicine Resources, China Medical University, Taichung, 404, Taiwan, Republic of China, Natural Products Research Laboratories, Division of Medicinal Chemistry and Natural Products, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina 27599-7360, and Graduate Institute of Integrated Medicine, China Medical University, Taichuang 404, Taiwan, Republic of China