1. Department of Chemistry, University of Nairobi, 30197-00100, Nairobi, Kenya
2. Department of Chemistry—BMC, Uppsala University, P.O. Box 756, SE-751 23 Uppsala, Sweden
3. Department of Chemistry, University of Antwerp, Groenenborgerlaan 171, B-2020 Antwerp, Belgium
4. Discovery Biology, Griffith Institute for Drug Discovery, Griffith University, Nathan, Qld 4111, Australia
5. University of Jyvaskyla, Department of Chemistry, P.O. Box 35, FI-40014 Jyväskylä, Finland
6. Institut für Chemie, Universität Potsdam, Karl-Liebknecht-Str. 24-25, D-14476 Potsdam, Germany
7. Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden