1. School of Pharmacy China Pharmaceutical University Nanjing 210009 China
2. Institute of Pharmacy and Molecular Biotechnology Ruprecht-Karls-Universität Heidelberg Im Neuenheimer Feld 364 69120 Heidelberg Germany
3. Institute of Medicinal and Pharmaceutical Chemistry Technische Universität Braunschweig Beethovenstr. 55 38106 Braunschweig Germany
4. Department of Organic Chemistry University Bayreuth Universitätsstr. 30 95440 Bayreuth Germany