1. School of Pharmacy, East China University of Science and Technology, 130 Mei‐long Road, Shanghai 200237 (P.R. China)
2. Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zuchongzhi Road, Shanghai 201203 (P.R. China)
3. Department of Chemistry & Chemical Biology, University of New Mexico, MSC03 2060, Albuquerque, NM 87131‐0001 (USA), Fax: (+1) 505‐277‐2609