1. Chemistry Department, College of Natural and Applied Sciences, University of Dar es Salaam, P.O. Box 35061, Dar es Salaam, Tanzania
2. Department of Chemistry - BMC, Uppsala University, SE-751 23 Uppsala, Sweden
3. Department of Chemistry and Molecular Biology, University of Gothenburg, SE-412 96 Gothenburg, Sweden
4. Center for Antibiotic Resistance Research (CARe) at the University of Gothenburg, Box 440, 405 30 Gotheburg, Sweden
5. Department of Chemistry - Ångström, Uppsala University, SE-751 20 Uppsala, Sweden