Synthesis of tripeptide derivatized cyclopentadienyl complexes of technetium and rhenium as radiopharmaceutical probes.
Org Biomol Chem
; 12(12): 1966-74, 2014 Mar 28.
Article
in En
| MEDLINE
| ID: mdl-24535293
ABSTRACT
We describe the syntheses of half-sandwich complexes of the type [(η(5)-Cp(CONH-R))M(CO)3] with M = Re or (99m)Tc. The R group represents different tri-peptides (tpe) which display high binding affinities for oligopeptide transporters PEPT2. The (99m)Tc complexes were prepared directly from [(99m)Tc(OH2)3(CO)3](+) and Diels-Alder dimerized, cyclopentadienyl derivatized peptides in water. This approach corroborates the feasibility of metal-mediated retro Diels-Alder reactions for the preparation of not only small molecules but also peptides carrying a [(η(5)-Cp)(99m)Tc(CO)3] tag. We synthesized the Diels-Alder product [(HCpCONH-tpe)2] from Thiele's acid [(η(5)-HCpCOOH)2] via double peptide coupling. The Re-complexes [(η(5)-CpCONH-tpe)Re(CO)3] were obtained by attaching [(Cp-COOH)Re(CO)3] directly to the N-terminus of peptides as received from SPPS. The authenticity of the (99m)Tc-complexes is confirmed by chromatographic comparison with the corresponding rhenium complexes, fully characterized by spectroscopic techniques.
Full text:
1
Database:
MEDLINE
Main subject:
Oligopeptides
/
Organometallic Compounds
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Radiopharmaceuticals
/
Cyclopentanes
Language:
En
Year:
2014
Type:
Article