1. School of Pharmacy Fudan University Shanghai 201203 P. R. China
2. State Key Laboratory of Drug Research Shanghai Institute of Materia Medica Chinese Academy of Sciences Shanghai 201203 P. R. China
3. Chemistry Department Faculty of Science University of Malaya Kuala Lumpur 50603 Malaysia
4. School of Pharmacy Lanzhou University Lanzhou 730000 Gansu P. R. China
5. National Center for Natural Products Research University of Mississippi Oxford MS 38677 USA
6. Colleges of Pharmacy and Medicine Medical University of South Carolina Charleston SC 29425-5700 USA
7. School of Advanced Study Taizhou University Taizhou 318000 Zhejiang P. R. China