1. Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, D-37077 Göttingen, Germany
2. Chemistry of Natural Compounds Department, Pharmaceutical Industries Division, National Research Centre, El-Behoos st., Dokki-Cairo 12622, Egypt
3. Botany and Microbiology Department, Faculty of Science, Damanhour University, Damanhour, Egypt