Glucosamine conjugates bearing N,N,O-donors: potential imaging agents utilizing the [M(CO)3]+ core (M = Re, Tc)

The design rationale, synthesis and radiolabeling evaluation of four glucosamine conjugated ligands for the [(99m)Tc(CO)(3)](+) core is described. The capability to bind the tricarbonyl core is initially demonstrated using the cold surrogate [Re(CO)(3)](+). The four compounds are competent chelates in binding [(99m)Tc(CO)(3)](+) as labeling studies show, with yields ranging from 79 to 96% and the resulting complexes showing stability in the presence of competing chelates for 24 h at 37 degrees C. The rhenium complexes were tested for hexokinase-catalysed phosphorylation, and the technetium complexes were tested for GLUT-1 mediated cell uptake--they showed a small amount of uptake but it was not glucose dependent, suggesting that it was not via the GLUT-1 transporters.