1. Chemistry of Natural and Microbial Products Department, Pharmaceutical and Drug Industries Research Division, National Research Center, 33 El Bohouth St.( former El Tahrir St.) Dokki, Giza, P.O. Box 12622, Egypt
2. Department of Chemistry, Faculty of Science, Cairo University, Giza, 12613, Egypt
3. Biochemistry Department, Genetic Engineering and Biotechnology Research Division, National Research Center, 33 El Bohouth St. (former El Tahrir St.) Dokki, Giza, P.O. Box 12622, Egypt