1. School of Pharmacy, College of Medicine, National Taiwan University, Jen-Ai Road, Sec. 1, Taipei 100, Taiwan, Republic of China, Department of Life Science, Fu-Jen University, Taipei Hsien, Taiwan, Republic of China, Division of Silviculture, Taiwan Forestry Research Institute, Taipei, Taiwan, Republic of China, and Graduate Institute of Natural Products, Chang Gung University, Taoyuan 333, Taiwan, Republic of China