1. School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing 210046, Jiangsu Province, P. R. China
2. Jiangsu Institute for Food and Drug Control, Nanjing 210019, Jiangsu Province, P. R. China
3. Nanjing Institute for Food and Drug Control, Nanjing, Jiangsu Province 211198, P. R. China
4. School of Environmental and Chemical Engineering, Jiangsu University of Science and Technology, Zhenjiang 212003, Jiangsu Province, P. R. China
5. Department of Chemistry, National University of Singapore, Singapore 117543, Singapore