Blood-Brain Barrier Penetrating Luminescent Conjugates Based on Cyclometalated Platinum(II) Complexes.

Herein we report on the synthesis, structural characterization and photophysical properties of cyclometalated Pt(II) complexes [Pt(N^C)(PPh(CHCOOH))Cl] (where N^C ligands are 2-phenylpyridine, (2-benzofuran-3-yl)pyridine, and (2-benzo[]tiophen-3-yl)pyridine) and their conjugates with the histidine-containing RRRRRRRRRRHVLPKVQA peptide. This peptide contains the RHVLPKVQA sequence, which is responsible for antiamyloid activity, and the Arg9 RRRRRRRRR domain, which shows improved translocation through cell membranes. The chemistry underpinning the conjugation is regioselective complexation between Pt(II) complexes and histidine residue in the peptide.