1. Department of Chemistry, Faculty of Science, University of Douala, P.O. Box: 24157 Douala, Cameroon
2. H.E.J. Research Institute of Chemistry, University of Karachi, 75270, Karachi, Pakistan
3. Natural Products Research Group, Department of Chemistry, Faculty of Engineering and Physical Sciences, University of Surrey, Guildford, GU2 7XH, United Kingdom
4. Department of Chemistry, Higher Teachers’ Training College, University of Yaoundé I, P.O. Box 47 Yaoundé, Cameroon
5. Pharmaceutical Research Center, Pakistan Council of Scientific & Industrial Research Complex, Karachi, Pakistan