1. Department
of Chemistry, University of Cape Town, Rondebosch 7701, South Africa
2. Department
of Biology and Biochemistry, University of Bath, Claverton Down, Bath BA2 7AY, U.K.
3. Institute
of Infectious Disease and Molecular Medicine, University of Cape Town, Observatory 7925, South Africa
4. South
African Medical Research Council Drug Discovery and Development Research
Unit, University of Cape Town, Rondebosch 7701, South Africa
5. Department
of Integrative Biomedical Sciences, University of Cape Town, Observatory 7925, South Africa