1. Laboratorium für Organische Chemie; Departement Chemie und Angewandte Biowissenschaften; ETH-Zürich; Hönggerberg HCI, Vladimir-Prelog-Weg 3 CH-8093 Zürich Switzerland
2. Department of Biosystems Science and Engineering; ETH Zürich; BSD H 368, Mattenstrasse 26 CH-4058 Basel Switzerland
3. Department of Chemistry; University of Basel; St. Johanns-Ring 19 CH-4056 Basel Switzerland
4. Swiss Tropical and Public Health Institute; Socinstrasse 57 CH-4051 Basel Switzerland