Synthesis and screening of bifunctional radiolabelled carborane-carbohydrate derivatives

A new bifunctional carborane ligand was prepared as a platform for the development of targeted molecular radioimaging and therapy agents. The carborane derivative was synthesized bearing a glucose substituent to increase the water solubility of the ligand and a benzoic acid group as a site for linking to amine containing targeting vectors. A convenient method to conjugate the ligand and the non-glycosylated analogue to amino groups was developed using simple active esters which were combined with a model amine generating two new N,N-diethyl(aminoethyl) benzamide derivatives. These were labelled with I-125 in good yield and the logP values measured for [I-125]-15 (logP = 0.82 +/- 0.04) and [I-125]-16 (logP = 1.53 +/- 0.01). The benzamides were also evaluated for their capacity to bind to B16F10 melanoma cells where the hydrophilic compound showed low binding while [I-125]-16 showed modest uptake (30.7 +/- 2.2%) after 24 h. (C) 2009 Elsevier B.V. All rights reserved.