1. Key Laboratory of Tropical Biological Resources of the Ministry of Education of China, Hainan University, Haikou 570228, PR China
2. Haikou Key Laboratory for Research and Utilization of Tropical Natural Products, Institute of Tropical Bioscience and Biotechnology, CATAS, Haikou 571101, PR China
3. College of Pharmacy, Guilin Medical University, Guilin, 541199, PR China