1. Shaanxi Key Laboratory of Natural Products & Chemical Biology, College of Chemistry & Pharmacy, Northwest A&F University, Yangling 712100, P. R. China
2. Hebei Key Laboratory of Analysis and Control of Zoonotic Pathogenic Microorganism and College of Science & Technology, Hebei Agricultural University, Huanghua, Hebei 061100, China
3. Attana, Stockholm SE-11419, Sweden