Melanoma uptake of (99m)Tc complexes containing the N-(2-diethylaminoethyl)benzamide structural element.

On the basis of the avid uptake of radioiodinated benzamides by melanoma cells, (99m)Tc complexes containing the structural elements of N-(dialkylaminoalkyl)benzamide pharmacophores have been synthesized and evaluated in vitro and in vivo for melanoma uptake. One of the complexes Tc-12 containing the ligand 4-(S-benzoyl-2-thioacetyl-glycyl-glycylamido)-N-(2-diethylaminoethyl)benzamide (11) displayed the highest melanoma uptake. The 1-h melanoma uptake values and the corresponding blood counts indicate an interdependence of tumor uptake and bioavailability of the (99m)Tc complexes.