1. School of Chemistry and Physics, University of Kwazulu-Natal, Pietermaritzburg Campus, Private Bag X01, Scottsville 3209, South Africa
2. Department of Chemical Sciences, Olabisi Onabanjo University, Ago-Iwoye, P. M. B. 2002, Nigeria
3. Discipline of Biochemistry, School of Life Sciences, University of Kwazulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa
4. Discipline of Pharmaceutical Sciences, School of Health Sciences, University of Kwazulu-Natal, Westville Campus, Private Bag X54001, Durban 4000, South Africa