1. Chongqing Key Laboratory of Natural Product Synthesis and Drug Research, and Chemical Biology Research Center, School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, P. R. China
2. Key Laboratory of Tropical Plant Resource and Sustainable Use, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun 666303, P. R. China
3. School of Pharmaceutical Engineering, Shenyang Pharmaceutical University, Shenyang 110016, P. R. China
4. State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing 210009, P. R. China