1. Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima, 770-8514, Japan
2. School of Pharmaceutical Sciences, Nagasaki University, Bunkyo-machi, Nagasaki, 852-8521 Japan
3. Shikoku Research Center, Forestry and Forest Products Research Institute, Asakuranishi-machi, Kochi, 780-8077, Japan
4. Kunming Institute of Botany, Chinese Academy of Science, Kunming 650204, China
5. Department of Chemistry, Rikkyo University, Nishi-Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan