1. Department
of Natural Products Chemistry, School of Pharmacy, Fudan University, No.
826 Zhangheng Road, Shanghai 201203, P. R. China
2. State
Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, No. 555 Zuchongzhi Road, Shanghai 201203, P. R. China
3. Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos 138669, Singapore