1. Department of Chemistry, Faculty of Science, University of Ngaoundere, Ngaoundere, Cameroon
2. Department of Chemical Engineering, School of Chemical Engineering and Mineral Industries, University of Ngaoundere, Ngaoundere, Cameroon
3. Department of Refining and Petrochemistry, National Advanced School of Mines and Petroleum Industries, The University of Maroua, Kaele, Cameroon
4. Laboratory of NMR and Molecular Imaging, Department of General, Organic and Biomedical Chemistry, University of Mons, Mons, Belgium
5. Dipartimento di Chimica, “Sapienza” Università di Roma, Rome, Italy