1. State Key Laboratory of Natural Medicines, Jiangsu Key Laboratory of Bioactive Natural Product Research, School of Traditional Chinese Pharmacy, China Pharmaceutical University, 24 Tong Jia Xiang, Nanjing210009, P. R. China
2. Department of Medicinal Chemistry, School of Pharmacy, Nanjing Medical University, 101 Longmian Avenue, Nanjing211166, P. R. China