1. College of Pharmacy, Ningxia Medical University, Yinchuan 750004, China
2. State Key Laboratory of Phytochemistry and Plant Resources in West China, Kunming Institute of Botany, Chinese Academy of Sciences, Kunming 650201, China
3. Graduate School of Chinese Academy of Sciences, Beijing 100039, China
4. Center for Drug Evaluation, State Food and Drug Administration, Beijing 100038, China