1. aOrganic and Bioorganic Chemistry, Faculty of Chemistry, Bielefeld University, Bielefeld, Germany;
2. bChemistry Department, Faculty of Science, Al-Azhar University, Cairo, Egypt;
3. cMicrobial Chemistry Department, Genetic Engineering and Biotechnology Research Division, National Research Centre, Giza, Egypt;
4. dPharmacognosy Department, Faculty of Pharmacy, Helwan University, Helwan, Egypt;
5. eBotany and Microbiology Department, Faculty of Science, Damanhour University, Damanhour, Egypt;
6. fChemistry of Natural Compounds Department, Pharmaceutical and Drug Industries Research Division, National Research Centre, Cairo, Egypt