1. Organic and Bioorganic Chemistry, Faculty of Chemistry, Bielefeld University, Bielefeld, Germany;
2. Chemistry Department, Faculty of Science, Al-Azhar University, Nasr City, Cairo, Egypt;
3. Pharmacognosy Department, Faculty of Pharmacy, Kasr el Aini st, Cairo University, Cairo, Egypt;
4. Red sea Marine Parks, Hurghada, Egypt;
5. Department of Chemistry, Inorganic and Structural Chemistry, Bielefeld University, Bielefeld, Germany;
6. Department of Chemistry of Natural Compounds, Pharmaceutical and Drug Industries Research Division, National Research Centre, Dokki-Cairo, Egypt