1. Department of Organic Chemistry, Faculty of Science, University of Yaoundé I, Yaoundé, Cameroon
2. Department of Engineering Process, National Higher Polytechnic School of Douala, University of Douala, Douala, Cameroon
3. University Institute of Wood Technology of Mbalmayo, University of Yaoundé I, Yaoundé, Cameroun
4. Department of Biochemistry, Faculty of Science, The University of Yaoundé I, Yaoundé, Cameroon
5. Inorganic and Structural Chemistry, Faculty of Chemistry, Bielefeld University, Bielefeld, Germany
6. Department Organic and Bioorganic Chemistry, Faculty of Chemistry, Bielefeld University, Bielefeld, Germany
7. Department of Chemistry, Higher Teacher Training College, University of Yaoundé I, Yaoundé, Cameroon