1. Department of Natural Medicines, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan
2. Graduate School of Science and Technology, Kumamoto University, Kumamoto 860-8555, Japan
3. Department of Pharmaceutical Biochemistry, Graduate School of Pharmaceutical Sciences, Kumamoto University, Kumamoto 862-0973, Japan
4. Sesoko Station, University of the Ryukyus, 3422 Sesoko, Motobu, Okinawa 905-0227, Japan
5. Graduate School of Pharmaceutical Sciences, Chiba University, Chiba 260-8675, Japan