1. Department of Chemistry, Faculty of Sciences, University of Buea, Buea, Cameroon
2. Department of Chemistry, Faculty of Science, University of Bamenda, Bamenda, Cameroon
3. Department of organic chemistry, Faculty of Science, University of Yaounde I, Yaounde, Cameroon
4. Department of Biochemistry, Faculty of Science, University of Douala, Douala, Cameroon
5. Chemistry Laboratory, Department of Chemistry, Faculty of Science, University of Douala, Douala, Cameroon