1. Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy; Northwest A&F University; 22 Xinong Road Yangling 712100 Shaanxi China
2. State Key Laboratory of Bioorganic & Natural Products Chemistry; Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Key Laboratory of Botanical Pesticide R&D in Shaanxi Province; Yangling Shaanxi 712100 China