DTPA-bisamide-based MR sensor agents for peroxidase imaging

The synthesis and some properties of two novel DTPA-bisamides are reported. These derivatives were designed as enzyme-activated contrast agents (CA) for magnetic resonance imaging. Both derivatives bear tyramido or 5-hydroxytryptamido groups that could be oligomerized in situ in the presence of peroxidase/H2O2 pair resulting in a net increase in longitudinal (R1) relaxivity.