Synthesis and Biodistribution of ~(125)I-Labelled Benzothiazole Derivatives as β-Amyloid Imaging Agents

In order to develop ~(123)I labelled probe for SPET imaging of A β plaques in Alzheimer's (disease), Four ~(125)I labelled benzothiazole derivatives are synthesized and their radiochemical purity are more than 95%. The biodistribution results in normal mice indicate that the radiolabelled probes have higher initial brain uptake:10.28, 3.62, 3.33 and 3.71%/g at 2 min post i.v. injection for 3′-~(125)I-BTA,3′-~(125)I-CBTA,3′-~(125)I-BTA-Ac and 3′-~(125)I-CBTA-Ac, respectively. Brain uptake ratios at 2 min to 60 min of 3′-~(125)I-BTA,3′-~(125)I-BTA-Ac and 3′-~(125)I-CBTA-Ac are 7.3, 6.2 and 5.7 respectively. The results reveal that 3′-~(123)I-BTA is a very potential agent for SPECT imaging of A β plaques in Alzheimer's disease.