1. Department of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
2. Swiss Tropical and Public Health Institute, Socinstrasse 57, 4051 Basel, Switzerland
3. University of Basel, 4002 Basel, Switzerland
4. South African Medical Research Council Drug Discovery and Development Research Unit, Department of Chemistry and Institute of Infectious Disease and Molecular Medicine, University of Cape Town, Rondebosch 7701, South Africa