1. State Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources, Key Laboratory for Chemistry and Molecular Engineering of Medicinal Resources (Ministry of Education of China), Collaborative Innovation Center for Guangxi Ethnic Medicine, School of Chemistry and Pharmaceutical Sciences, Guangxi Normal University, Guilin, Guangxi 541004, P. R. China
2. State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, Jiangsu 211198, P. R. China