Bicyclic polyaminoacid metal complexes, their process of preparation and their application in medical imaging

A metal chelate of a compound of formula

• wherein
• R has the formula
• and
• Z is a bond or a group selected from the group consisting of CH2, CH2—CO—NH and (CH2)2—NH—CO,
• Z′ is a bond or a radical selected from the group consisting of O, S, NQ, CH2, CO, CO—NQ, NQ—CO, NQ—CO—NQ and CO—NQ—CH2—CO—NQ,
• Z″ is a bond or a radical selected from the group consisting of CO—NQ, NQ—CO and CO—NQ—CH2—CO—NQ groups,
• p and q are integers, the sum of which has a value from 0 to 3,
• R1, R2, R3, R4, R5, independently of one another, are selected from the group consisting of H, Br, Cl, I, CO—NQ1Q2 and NQ1—CO—Q2, Q1 and Q2, which are identical or different, being H or (C1-C6) alkyl optionally interrupted by one or more oxygen atoms and at least one of the R1 to R5 groups being an amido group,
• or R1, R3, and R5 are, independently of one another, H, Br, Cl or I, and R2 and R4, which are identical, have the formula
• such that Z′″ is a radical selected from the group consisting of CO—NQ, CO—NQ—CH2—CO—NQ, CO—NQ—CH2, CO—NQ(CH2)2—NQ—CO and NQ—CO—NQ, and R′1, R′3 and R′5, which are identical or different, are H, Br, Cl or I, and Q′1 and Q′2, which are identical or different, are H or (C1-C6) alkyl optionally interrupted/by one or more oxygen atoms,
• Q is H or (C1-C4) alkyl,
• the alkyl groups being optionally mono- or polyhydroxylated, and
• wherein the metal of the metal chelate is a paramagnetic ion, a radioactive ion, or a transmetallation-effecting ion.