1. Key Laboratory of Tropical Medicinal Plant Chemistry of Ministry of Education, Hainan Normal University, Haikou, P. R. China
2. Key Laboratory of Southern Medicinal Plants Resources of Haikou City, Hainan Normal University, Haikou, P. R. China
3. Guangxi Key Laboratory of Functional Phytochemicals Research and Utilization, Guangxi Institute of Botany, Guangxi Zhuang Autonomous Region and Chinese Academy of Sciences, Guilin, P. R. China