1. Kenya Medical Research Institute, P.O. Box 54840-00200, Nairobi, Kenya
2. Department of Biological Sciences, University of Eldoret, P.O. Box 1125-30100, Eldoret, Kenya
3. Masinde Muliro University of Science and Technology, P.O. Box 190-50100, Kakamega, Kenya
4. Department of Pharmaceutical Chemistry, School of Pharmacy, University of Nairobi, P.O. Box 19676-00202, Nairobi, Kenya