1. Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Yamashiro-cho, Tokushima, 770-8514, Japan
2. Kunming Institute of Botany, Chinese Academy of Science, Kunming 654204, China
3. Department of Life Science, Rikkyo University, Nishi- Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan
4. Department of Chemistry, Rikkyo University, Nishi- Ikebukuro, Toshima-ku, Tokyo 171-8501, Japan