Patent ID: 7608243

Claim:
A compound comprising a peptidic vector and at least one fluorescein dye, wherein the peptidic vector and the fluorescein dye are coupled, and wherein said peptidic vector is defined by formula I: R a —C(═O)—X 1 —X 2 —X 3 -G-D-X 4 —X 5 —X 6 —X 7 (I) wherein Formula I comprises two cyclising bridges, and wherein R a represents —(CH 2 ) n — or —(CH 2 ) n —C 6 H 4 — forming a bridge to one of X 2 , X 4 or X 6 , wherein n represents a positive integer from 1 to 10, and X 1 represents a bond or 1, 2, 3, 4 or 5 amino acid residues, wherein one amino acid residue is optionally functionalised with a spacer moiety, or said amino acid residue possesses a functional side-chain chosen from an acid or amine group, X 2 is an amino acid residue forming a cyclising bridge to one of R a , X 4 or X 6 ; X 3 represents arginine or N-methylarginine, G represents glycine, D represents aspartic acid, X 4 is an amino acid residue forming a cyclising bridge to one of R a , X 2 or X 6 ; X 5 represents a hydrophobic amino acid, and X 6 represents an amino acid residue forming a cyclising bridge to either R a , X 2 or X 4 , and X 7 represents a spacer or biomodifier moiety or is absent, wherein said biomodifier comprises a monodisperse polyethylene glycol (PEG) building block comprising 1 to 10 units of said building block; and, wherein at least one of the fluorescein dye is linked to one or more of the groups X 1 , X 6 , or X 7 optionally via a spacer group.