1. School of Sciences, China Pharmaceutical University, Nanjing 211198, P. R. China
2. School of Pharmacy, China Pharmaceutical University, Nanjing 211198, P. R. China
3. State Key Laboratory of Natural Medicines, School of Science, China Pharmaceutical University, Nanjing 211198, P. R. China
4. Laboratory of Molecular Design and Drug Discovery, School of Sciences, China Pharmaceutical University, Nanjing 211198, P. R. China