1. State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany; Chinese Academy of Sciences; Kunming 650204 People's Republic of China
2. Department of Chemistry; Yunnan Normal University; Kunming 650092 People's Republic of China
3. Key Laboratory of Medicinal Chemistry for Natural Resource, Ministry of Education, School of Chemical Science and Technology; Yunnan University; Kunming 650091 People's Republic of China