Norah Al-Hokbany
Assistant Professor in the Department of Chemistry at Science College of King Saud University
Title: Synthesis and characterization of a {ReO}3+ complex with S- and N-donor ligands and of its 99mTc analog
Biography
Biography: Norah Al-Hokbany
Abstract
A novel mixed-ligand 99mTc complex with mercaptobenzothiazole (mer) as ligand and aminothia- zole (amino) as coligand was prepared and evaluated as potential brain radiopharmaceutical. Preparation at tracer level was accomplished by substitution, using 99mTc- gluconate as precursor and a coligand/ ligand ratio of 5. Under these conditions, the labeling yield was over 97% and the major product with radiochemical purity >97% was isolated by HPLC and used for biological evaluation. The reaction of [ReO(Citrate)2]- with mer and amino in hot MeOH yields [ReO(mer)(amino)OH(H2O)2]. The DFT study demonstrated that the complex con- tains distorted octahedral ReO(V). The Re coordination sphere consists of the terminal oxo group, the S donor atom of the deprotonated mer, the N atom of the deprotonated amino, OH group, and two water molecules. Biodistribution in mice demonstrated early brain uptake, fast blood clearance, and excretion through hepatobiliary system. Although the brain/blood ratio increased significantly with time, the novel 99mTc complex did not exhibit ideal properties as brain perfusion radiopharmaceutical since brain uptake was too low.