Thesis & Dissertations

Synthesis, Characterization, and Antioxidant Activity of a Series of Quinoxaline-1, 4-di-N-Oxide Analogues


Antioxidants are an important class of compounds used to protect the human body against radicals that accumulate as a consequence of excessive oxidations. If not quenched, these radicals will cause havoc leading to serious pathological conditions. In this project, we evaluated the antioxidant efficacy of several quinoxaline-1,4-dioxide analogues. This class of compounds has been investigated extensively for its antibacterial and anticancer activities. On the other hand, literature reports demonstrating its antioxidant properties are scarce, and much research is needed in this area. An interesting molecule that belongs to this family is 2-benzoyl-3-phenyl-6,7-dichloroquinoxaline-1,4-dioxide (DCQ) which demonstrated excellent anticancer properties. DCQ and its analogues were synthesized under Beirut Reaction conditions and its structure was confirmed using nuclear magnetic resonance (NMR) spectroscopy, mass spectroscopy, and infrared spectroscopy. In addition, the antioxidant activity of DCQ and its analogues was investigated using the DPPH radical scavenging assay. DCQ exhibits poor water solubility thus rendering the oral administration route inconvenient and unpleasant for potential patients. To overcome this limitation, DCQ was formulated inside an acid sensitive acetelated dextran nanoparticle. The nanoparticle formulation hydrolyzes in an acidic environment such encountered as the one encountered in the stomach, thus releasing the drug just before the small intestine where absorption into the blood stream will take place. The size of the nanoparticles was evalauted by scanning electron microscopy (SEM), and the release profile of the DCQ was assessed by thin layer chromatography (TLC) and High Performance Liquid Chromatography (HPLC).


Marwa Hasan Al Makdah


Mohammad El-Dakdouki, Karim Raafat