1. State Key Laboratory of Medicinal Chemical Biology College of Pharmacy Nankai University Tianjin 300071 China
2. College of Chemistry Nankai University Tianjin 300071 China
3. Department of Chemistry University of South Florida 4202 E. Fowler Avenue Tampa FL 33620 USA
4. School of Food Science and Pharmaceutical Engineering Nanjing Normal University No. 1 Wenyuan Road Nanjing 210046 China
5. National Institute for Advanced Materials Nankai University Tianjin 300071 China