1. Key Laboratory of Natural Medicine and Immuno‐Engineering of Henan Province, Henan University, Jinming Campus, Kaifeng, Henan, 475004 (P.R. China)
2. Division of Chemistry and Biological Chemistry, Nanyang Technological University, 21 Nanyang Link, 637371 (Singapore)
3. Institute of Organic Chemistry and Technology, University of Pardubice, Faculty of Chemical Technology, Studentská 573, Pardubice, 53210 (Czech Republic)