1. Department of Toxicology , National Public Health Laboratory , Khartoum , Sudan
2. Department of Pharmaceutical Chemistry, Faculty of Clinical Pharmacy , Ibn Sina University , Khartoum , Sudan
3. Chemistry Department, College of Science , Imam Mohammad Ibn Saud Islamic University (IMSIU) , Riyadh 11623 , Saudi Arabia
4. Department of Chemistry, Faculty of Science , University of Khartoum , P.O. Box 321, 11115 Khartoum , Sudan
5. Department of Basic Sciences, Faculty of Engineering Sciences , Omdurman Islamic University , Omdurman , Sudan
6. Department of Biochemistry, Medicinal and Aromatic Plants Traditional Medicine and Research Institute , National Center for Research , Khartoum , Sudan