1. Department of organic chemistry Faculty of Science Yaoundé University of Yaoundé I P.O. Box 812 Cameroon
2. Faculty of Pharmacy ‘‘Iuliu Hatieganu'' University of Medicine and Pharmacy Victor Babes 41 400012 Cluj-Napoca Romania
3. Faculty of Science University of Dschang P.O. Box 67 Dschang Cameroon
4. Department of Pharmaceutical Biology Institute of Pharmacy and Biochemistry Johannes Gutenberg University Mainz 55128 Germany
5. Department of Pharmacognosy and Pharmaceutical Chemistry Faculty of Medicine and Biomedical Sciences University of Yaoundé 1 P.O. Box. 8664 Yaoundé Cameroon
6. Department of Chemistry CFM Federal University of Santa Catarina 88040-900 Florianópolis SC Brazil