1. Department of Chemistry, School of Natural Sciences, University of Zambia, P.O. Box 32379, Lusaka 10101, Zambia
2. Department of Pharmacognosy and Pharmaceutical Chemistry, Kenyatta University, P.O. Box 14548-00400, Nairobi 00100, Kenya
3. Department of Pharmacology and Pharmacognosy, School of Pharmacy, Jomo Kenyatta University of Agriculture and Technology, P.O. Box 62000-00200, Nairobi 00100, Kenya