1. Institute of Organic Chemistry; Technische Universität Braunschweig; Hagenring 30 38106 Braunschweig Germany
2. Center for Marine Biotechnology and Biomedicine; Scripps Institution of Oceanography; University of California San Diego; 9500 Gilman Drive La Jolla CA 92093 USA
3. Skaggs School of Pharmacy and Pharmaceutical Sciences; University of California San Diego; 9500 Gilman Drive La Jolla CA 92093 USA