1. Department of Biochemistry, Faculty of Medicine and Biomedical Sciences, P.O. Box 1364, University of Yaoundé 1, Yaounde, Cameroon
2. Department of Organic Chemistry, Faculty of Sciences of the University of Yaoundé 1, P.O. Box 812, Yaounde, Cameroon
3. Public Health and Epidemiology Unit, Centre Pasteur Du Cameroun, P. O. Box 1274, Yaoundé, Cameroon
4. Department of Biochemistry, Faculty of Sciences, University of Dschang, Dschang, Cameroon