[1] Univ Zululand, Dept Biochem & Microbiol, Private Bag X1001, ZA-3886 Kwa Dlangezwa, South Africa
[2] Univ Johannesburg, Dept Appl Chem, Doornfontein Campus,POB 17011, ZA-2028 Johannesburg, South Africa
[3] Afe Babalola Univ, Coll Sci, Dept Biochem, PMB 5454, Ado Ekiti 360001, Nigeria