1. Department of Medicinal Chemistry, School of Pharmacy, China Pharmaceutical University, 24 Tongjiaxiang, Nanjing 210009, P. R. China
2. School of Pharmacy, Wannan Medical College, Wuhu 241002, P. R. China
3. State Key Laboratory of Natural Products, Jiangsu Key Laboratory of TCM Evaluation and Translational Research, Department of Pharmacology of Chinese Material Medical, School of Traditional Chinese Pharmacy, China Pharmaceutical University, Nanjing 211198, P. R. China