Synthesis of neurotensin(9–13) analogues exhibiting enhanced human neurotensin receptor binding affinities

Recent evidence is consistent with neurotensin (NT)(8–13) adopting a Type I β-turn conformation while binding the NT receptor, which would place the cationic side-chains of Arg(8) and Arg(9) in close proximity. This was the basis for the design, synthesis and analysis of truncated NT(9–13) analogues Figure 1 and Scheme 1 with dicationic position 9 side-chains to emulate the functions of the 8 and 9 side-chains of NT(8–13).