TY - JOUR
T1 - (S)-5-(p-nitrobenzyl)-PCTA, a promising bifunctional ligand with advantageous metal ion complexation kinetics
AU - Tircsó, Gyula
AU - Benyó, Eniko Tircsóné
AU - Suh, Eul Hyun
AU - Jurek, Paul
AU - Kiefer, Garry E.
AU - Sherry, A. Dean
AU - Kovács, Zoltán
PY - 2009/3
Y1 - 2009/3
N2 - A bifunctional version of PCTA (3,6,9,15-tetraazabicyclo[9.3.1]pentadeca- l(15),11,13-triene-3,6,9,-triacetic acid) that exhibits fast complexation kinetics with the trivalent lanthanide(III) ions was synthesized in reasonable yields starting from N,N′,N″-tristosyl-(S)-2-(p-nitrobenzyl)- diethylenetriamine. pH-potentiometric studies showed that the basicities of p-nitrobenzyl-PCTA and the parent ligand PCTA were similar. The stability of M(N02-Bn-PCTA) (M = Mg2+, Ca2+, Cu 2+, Zn2+) complexes was similar to that of the corresponding PCTA complexes, while the stability of Ln3+ complexes of the bifunctional ligand is somewhat lower than that of PCTA chelates. The rate of complex formation of Ln(N02-Bn-PCTA) complexes was found to be quite similar to that of PCTA, a ligand known to exhibit the fastest formation rates among all lanthanide macrocyclic ligand complexes studied to date. The acid-catalyzed decomplexation kinetic studies of the selected Ln(NG=2-Bn-PCTA) complexes showed that the kinetic inertness of the complexes was comparable to that of Ln(DOTA) chelates making the bifunctional ligand NO2-Bn-PCTA suitable for labeling biological vectors with radioisotopes for nuclear medicine applications.
AB - A bifunctional version of PCTA (3,6,9,15-tetraazabicyclo[9.3.1]pentadeca- l(15),11,13-triene-3,6,9,-triacetic acid) that exhibits fast complexation kinetics with the trivalent lanthanide(III) ions was synthesized in reasonable yields starting from N,N′,N″-tristosyl-(S)-2-(p-nitrobenzyl)- diethylenetriamine. pH-potentiometric studies showed that the basicities of p-nitrobenzyl-PCTA and the parent ligand PCTA were similar. The stability of M(N02-Bn-PCTA) (M = Mg2+, Ca2+, Cu 2+, Zn2+) complexes was similar to that of the corresponding PCTA complexes, while the stability of Ln3+ complexes of the bifunctional ligand is somewhat lower than that of PCTA chelates. The rate of complex formation of Ln(N02-Bn-PCTA) complexes was found to be quite similar to that of PCTA, a ligand known to exhibit the fastest formation rates among all lanthanide macrocyclic ligand complexes studied to date. The acid-catalyzed decomplexation kinetic studies of the selected Ln(NG=2-Bn-PCTA) complexes showed that the kinetic inertness of the complexes was comparable to that of Ln(DOTA) chelates making the bifunctional ligand NO2-Bn-PCTA suitable for labeling biological vectors with radioisotopes for nuclear medicine applications.
UR - http://www.scopus.com/inward/record.url?scp=63749104476&partnerID=8YFLogxK
U2 - 10.1021/bc8004914
DO - 10.1021/bc8004914
M3 - Article
C2 - 19220012
AN - SCOPUS:63749104476
SN - 1043-1802
VL - 20
SP - 565
EP - 575
JO - Bioconjugate Chemistry
JF - Bioconjugate Chemistry
IS - 3
ER -