1. School of Chemistry and Pharmaceutical
Engineering, Shandong Polytechnic University, Jinan 250353, P.R. China
2. State Key Laboratory of Drug
Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203,
P.R. China
3. Department of
Chemistry and Biochemistry, University of Bern, Freiestrasse 3, CH-3012, Bern,
Switzerland