1. Department of Chemistry, University of Fort Hare, Alice, Eastern Cape, South Africa
2. Durban University of Technology, Durban, South Africa
3. Wits Advanced Drug Delivery Platform Research Unit, Department of Pharmacy and Pharmacology, School of Therapeutic Science, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa
4. Drug Discovery and Smart Molecules Research Labs, Centre for Natural Product Research, Department of Chemical Sciences, University of Johannesburg, Johannesburg, South Africa