1. Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, Yunnan Research & Development Center for Natural Products, and School of Chemical Science and Technology, Yunnan University, No. 2 Cuihu North Road, Kunming 650091, China
2. State Key Laboratory of Applied Organic Chemistry, College of Chemistry and Chemical Engineering, Lanzhou University, 222 Tianshui Nanlu, Lanzhou 730000, China
3. College of Chemistry and Chemical Engineering, China West Normal University, No. 1 Shida Road, Nanchong 637002, China