1. Institute
of Pharmaceutical Biology and Phytochemistry (IPBP), University of Muenster, PharmaCampus Corrensstrasse 48, Muenster D-48149, Germany
2. Department
of Chemistry, Egerton University, P.O. Box 536, Egerton 20115, Kenya
3. Swiss Tropical and Public Health Institute (Swiss TPH), Socinstrasse 57, Basel CH-4051, Switzerland
4. University of Basel, Petersplatz
1, Basel CH-4003, Switzerland