Radiolabeling of thioguanine with 125I for diagnosis and therapy: in vitro and in vivo evaluation
- 84 Downloads
Labeling was carried out by direct iodination of thioguanine (100 μg) with radioiodine in a fast single step at 60 °C, to produce iodo-6-thioguanine (125I-S6G). Chloramine-T (200 μg) was used as oxidizing agent to oxidize the iodide ion to the iodonium ion, at pH 7 and the reaction time was 30 min. A high radiochemical yield of 96.4% was obtained. The labeled compound was quantitatively separated and purified by means of high pressure liquid chromatography (HPLC) with a radiochemical purity greater than 98%, which facilitates its clinical use for human application. The biodistribution of 125I-6-thioguanine was studied by injection of the tracer in both normal and tumor bearing mice. The uptake in ascetic fluid was 35.4 and 23.9% at 1 and 24 h post intravenous injection (h.p.i.), respectively, indicating the suitability of this labeled compound for use as a radiopharmaceutical agent.
Keywords125I Thioguanine Radioiodination Biodistribution
The authors wish to thank the editor and the referees of the JRNC for their cooperation and valuable comments and also Prof. Dr. K. Farah for her efforts in reviewing the manuscript.
- 6.Yan T, Berry SE, Desai AB, Kinsella T (2003) J Clin Cancer Res 9:2327Google Scholar
- 8.Maybaum J, Mandel HG (1983) Cancer Res 43:3852Google Scholar
- 11.Singh K, Groth-Vasselli B, Farnsworth P, Rai D (1996) Res Commun Mol Pathol Pharmacol 94:129Google Scholar
- 12.Sponer J, Leszczynski J, Hobza P (1997) J Phys Chem 101:9489Google Scholar
- 17.K. Attallah (2002) M.Sc. Pharmaceutics, EAEA, p 91Google Scholar
- 20.Cynthia BF, Roger KD, Kaumann AJ, Theodore LS, Lutz B (1979) J Mol Pharmacol 12:328Google Scholar
- 21.Rayudu GVS (1983) Radiotracers for medical application, CRS series in Radiotracers in Biology and Medicine vol 11Google Scholar
- 22.Saccavini JC, Bruneau C (1984) IAEA CN 4519:153Google Scholar