1. Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, P. R. China
2. Guangxi Key Laboratory of Agricultural Resources Chemistry and Biotechnology, College of Chemistry and Food Science, Yulin Normal University, Yulin, P. R. China
3. Key Laboratory of Medicinal and Edible Plants Resources of Hainan Province, School of Chemical and Material Engineering, Hainan Vocational University of Science and Technology, Haikou, P. R. China