1. Guangzhou Institute for Drug Control, 23 Xizeng Road, Xicun Guangzhou, 510160, People's Republic of China, Tsukuba Medicinal Plant Research Station, National Institute of Health Sciences, Hachimandai 1, Tsukuba, Ibaraki 305-0843, Japan, and National Institute of Health Sciences, Kamiyoga 1-18-1, Setagaya-ku, Tokyo 158-8501, Japan