1. Department of Organic Chemistry, Faculty of Science, University of Yaounde I, Yaounde, Cameroon
2. Department of Chemistry, Organic and Bioorganic Chemistry, Bielefeld University, Bielefeld, Germany
3. Department of Biochemistry, Faculty of Science, University of Dschang, Dschang, Cameroon
4. Institute of Pharmaceutical Sciences of Western Switzerland, University of Geneva, Geneva, Switzerland
5. Department of Chemistry, Higher Teachers’ Training College, University of Maroua, Maroua, Cameroon
6. Inorganic and Structural Chemistry, Department of Chemistry, Bielefeld University, Bielefeld, Germany
7. Centre d’Instrumentation en Résonance Magnétique (CIREM) Laboratoire de Résonance Magnétique Nucléaire Haute Résolution Université libre de Bruxelles (ULB), Brussels, Belgium
8. Faculty of Pharmacy, Microbiology, Bioorganic and Macromolecular Chemistry Unit, Université Libre de Bruxelles, Brussels, Belgium