1. Key Laboratory of Tropical Medicinal Resource Chemistry of Ministry of Education, Hainan Normal University, Haikou, Hainan 571158, People’s Republic of China
2. Key Laboratory of Tropical Medicinal Plant Chemistry of Hainan Province, College of Chemistry and Chemical Engineering, Hainan Normal University, Haikou, Hainan 571158, People’s Republic of China
3. Institute of Marine Drugs, Guangxi University of Chinese Medicine, Nanning, Guangxi 530200, People’s Republic of China