1. School of Chemistry and Physics Westville Campus University of Kwazulu-Natal Private Bag X54001 Durban 4000 South Africa
2. Department of Chemical Sciences Olabisi Onabanjo University P.M.B 2002 Ago-Iwoye Nigeria
3. Department of Biochemistry, Genetics and Microbiology Faculty of Natural Science University of Pretoria Private Bag X20 Hatfield 0028 South Africa