Improved synthesis of nicotinamide derivatives as useful precursors for PET tracers for imaging malignant melanoma
U. Seddik1, H. Aglan1, G. Trencsényi2, J. P. Szabó2, I. Kertész2, S. A. Kandil1, *
The rapid synthesis of two [18F]fluoronicotinamide derivatives, namely, [18F]MEL050 and [18F]MEL-2F has been simply performed starting from commercial materials. [18F]MEL-2F is a new potential analogue PET-probe for melanoma imaging. [18F]MEL050 is already a convenient PET imaging probe for early specific diagnosis. The synthesis involves coupling step to obtain the precursor followed by 18F-fluorination process. During the synthesis of the precursors different coupling reagents, such as HBTU, TFFH, HOBT, COMU and PyCIU have been tested. PyClU was found the best to reduce the coupling period to < 1h. The labelled compounds were purified by a semi-preparative column (Discovery® Bio Wide Pore C18, 15 x 10 mm, 10 µm). In the in-vitro study three kinds of cells, namely, Melur (melanin free), KB-3 carcinoma cell line (non-melanoma) and B16-F10 melanoma cell line were used to evaluate the uptake of the radiotracers.
* Address correspondence to this author at Cyclotron Project, Nuclear Research Centre, Atomic Energy Authority, B.O. 13759, Cairo, Egypt; Fax: +2 0246220086; Tel: +2 02 446 91 743; E-mail: email@example.com