1. Organic and Bioorganic Chemistry, Department of Chemistry , Bielefeld University , Universitätsstraße 25 , D-33501 Bielefeld , Germany
2. Chemistry Department, Faculty of Science , Al-Azhar University , Nasr City-Cairo 11884 , Egypt
3. Microbiology Department, Faculty of Science , Helwan University , Helwan-Cairo , Egypt
4. Botany and Microbiology Department, Faculty of Science , Damanhour University , Damanhour , Egypt
5. Chemistry of Natural Compounds Department, Pharmaceutical and Drug Industries Research Division , National Research Centre , El-Behoos St. 33 , Dokki-Cairo 12622 , Egypt