1. Department of Medicinal Chemistry, Shanghai Institute of Materia Medica (SIMM), Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, P. R. China
2. University of Chinese Academy of Sciences, No. 19A Yuquan Road, Beijing 100049, P. R. China
3. Division of Antitumor Pharmacology, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica (SIMM), Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, P. R. China