HSV1-tk gene expression imaging agents

In this study, we synthesized Tc(CO)3-2 0-aminomethylpyridyl-20-deoxyuridine (Tc(CO)3-AMPDU) and Tc(CO)3-aminoethylpyridyl-20-deoxyuridine (Tc(CO)3-AEPDU) as potential agents for imaging the expression of the non-invasive herpes simplex virus type-1 thymidine kinase. AMPDU and AEPDU were synthesized from uridine in five chemical steps and then labeled with [Tc(CO)3(H2O)3] + (370MBq/0.5mL) at 100 1C for 10min. Under optimal conditions (0.5 and 1.0mg for AMPDU and AEPDU and heating for 10min), the labeling efficiency was 95.372.8% for AMPDU and 94.275.1% for AEPDU. To validate the chemical structure of Tc(CO)3-labeled compounds, we also synthesized ReBr(CO)3-AMPDU and ReBr(CO)3-AEPDU by reacting [Et4N][ReBr3(CO)3] and AMPDU or AEPDU in methanol at 25 1C for 6 h. Tc(CO)3-AMPDU and Tc(CO)3-AEPDU had the same retention time on HPLC analysis as ReBr(CO)3-AMPDU and ReBr(CO)3-AEPDU. Tc(CO)3-AMPDU and Tc(CO)3-AEPDU had high radiochemical stabilities of 98.171.5% and 98.071.7% for 6 h, respectively. r 2008 Elsevier Ltd. All rights reserved.