1. College of Chemistry & Pharmacy, State Key Laboratory of Crop Stress Biology for Arid Areas, Northwest A&F University, Yangling 712100, China
2. Key Laboratory of Botanical Pesticide R&D in Shaanxi Province, Yangling 712100, China
3. Department of Pharmacy, Changzhi Medical College, Changzhi 046000, China
4. State Key Laboratory of Bioorganic and Natural Products Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 200032, China