1. Department of Chemistry, Faculty of Science, Laboratory of Applied Synthetic Organic Chemistry, University of Dschang , P.O. Box 67 Dschang , Republic of Cameroon
2. Department of Biochemistry, Faculty of Science, Research Unit of Microbiology and Antimicrobial Substances, University of Dschang , PO Box 067 Dschang , Republic of Cameroon
3. Polymer Chemistry Laboratory, Faculty of Life Sciences, Rhein-Waal University of Applied Sciences, Marie-Curie Strasse 1 , D-47533 Kleve , Germany
4. Department of Chemistry, Carleton University , 1125 Colonel By Drive, K1S 5B6 , Ottawa , Canada