Trends in NMR chemical shifts and ligand mobility of TcO(V) and ReO(V) complexes with aminothiols

Pelecanou, Maria; Chryssou, Katerina; Stassinopoulou, C. I.

doi:10.1016/s0162-0134(99)00227-5

Cited by 15 publications

(13 citation statements)

References 24 publications

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“…Chemical‐shift differentiation of the geminal protons on C‐6 and C‐7 is smaller for 99 Tc‐1 than for Re‐1 and it becomes nonexistent for protons on C‐9 and C‐10 of the linker chain, thereby possibly indicating higher chelate mobility for the 99 Tc‐1 complex than for Re‐1 . The Re‐1 / 99 Tc‐1 comparison data are in agreement with the trends reported for ReO(V) 3+ and TcO(V) 3+ homologous complexes with diaminedithiols 34…”

Section: Resultssupporting

confidence: 89%

A Phenylbenzothiazole Conjugate with the Tricarbonyl fac‐[M(I)(CO)₃]⁺ (M = Re, ⁹⁹Tc, ^99mTc) Core for Imaging of β‐Amyloid Plaques

et al. 2012

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The 2-(4Ј-aminophenyl)-6-methylbenzothiazole that is known to display affinity and specificity toward the amyloid plaques of Alzheimer's disease (AD) has been joined to the tricarbonyl [M(CO) 3 NNO] chelate (M = Re, 99 Tc, and 99m Tc) through a five-carbon linker chain to generate the neutral complex 1 (namely, Re-1 for M = Re; 99 Tc-1 for M = 99 Tc; and 99m Tc-1 for M = 99m Tc) with the aim of developing a singlephoton emission computed tomography (SPECT) radiodiagnostic agent for AD. Re-1 was characterized by spectroscopic methods and X-ray crystallography, whereas the detailed4279 NMR spectroscopic analysis of 99 Tc-1 demonstrated its structural similarity to Re-1. Complexes Re-1 and 99 Tc-1 display selective binding affinity for amyloid plaques as evidenced by fluorescence spectroscopy, whereas the biodistribution data of 99m Tc-1Ϫcharacterized by relatively low brain uptake, fast clearance from brain and blood, and in vivo sta-bilityϪare considered encouraging for further elaboration on the structural features of 1 in the direction of increased brain uptake.Aβ plaques in living brain tissue [7][8][9] and demonstrated the potential utility of these agents. The most widely studied PET amyloid imaging agent is the 2-phenylbenzothiazole derivative 2-(4Ј-[ 11 C]methylaminophenyl)-6-hydroxybenzothiazole (Pittsburgh compound-B, [ 11 C]PiB), a neutral derivative of the amyloid binding dye thioflavin-T (Scheme 1) that is employed in clinical practice. The histological and Scheme 1. Structures of thioflavin T, Pittsburg compound B (PiB), and complex 1.www.eurjic.org

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Section: Resultssupporting

confidence: 89%

A Phenylbenzothiazole Conjugate with the Tricarbonyl fac‐[M(I)(CO)₃]⁺ (M = Re, ⁹⁹Tc, ^99mTc) Core for Imaging of β‐Amyloid Plaques

et al. 2012

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“…Furthermore, the β ‐emitting radioisotopes of Tc, 99 Tc (t 1/2 =2.12 × 105 years, E max = 0.29 MeV) are similar to radioisotopes of rhenium 186 Re (E max = 1.07 MeV) and 188 Re (E max = 2.12 MeV) that also are β ‐emitting, which are already used in nuclear medicine for radiotherapy applications . The previous studies of NMR spectroscopy, involving the research group of Pelecanou et al ., point out that Tc and Re complexes present similar structural properties …”

Section: Introductionmentioning

confidence: 99%

⁹⁹Tc NMR as a promising technique for structural investigation of biomolecules: theoretical studies on the solvent and thermal effects of phenylbenzothiazole complex

Mancini

Souza

Caetano

et al. 2014

Magnetic Reson in Chemistry

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The phenylbenzothiazole compounds show antitumor properties and are highly selective. In this paper, the (99)Tc chemical shifts based on the ((99m)Tc)(CO)3 (NNO) complex conjugated to the antitumor agent 2-(4'-aminophenyl)benzothiazole are reported. Thermal and solvent effects were studied computationally by quantum-chemical methods, using the density functional theory (DFT) (DFT level BPW91/aug-cc-pVTZ for the Tc and BPW91/IGLO-II for the other atoms) to compute the NMR parameters for the complex. We have calculated the (99)Tc NMR chemical shifts of the complex in gas phase and solution using different solvation models (polarizable continuum model and explicit solvation). To evaluate the thermal effect, molecular dynamics simulations were carried, using the atom-centered density matrix propagation method at the DFT level (BP86/LanL2dz). The results highlight that the (99)Tc NMR spectroscopy can be a promising technique for structural investigation of biomolecules, at the molecular level, in different environments.

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“…This upfield shift is unique among all the protons of the complexes and can be ascribed to the magnetic anisotropy of the oxometal center and the coordination sphere that mainly affects protons in the vicinity of the complexing site. [55][56][57] The complexes remained stable in solution for a period of several months, and no decomposition or conversion into isomeric forms was observed.…”

Section: Synthesismentioning

confidence: 97%

Structural Assessment and Biological Evaluation of Two N₃S Bombesin Derivatives

et al. 2009

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The aim of the present study is the evaluation of the (99m)Tc complexes of two bombesin-like peptides: Gly1'-Gly2'-Cys3'-Aca-BN[2-14] (BN-1.1) and Gly1'-Gly2'-Cys3'-Aca-BN[7-14] (BN-1.1p). The BN derivatives were synthesized according to the solid phase peptide synthesis method, and characterized by ESI-MS and NMR. (185/187)Re-BN-1.1 and (185/187)Re-BN-1.1p were also identified by ESI-MS and NMR. The (99m)Tc complexes were stable over time in human plasma, while they degraded rapidly in kidney-liver homogenates. The peptides and their (99m)Tc complexes showed high affinity for the human GRP receptors expressed in PC-3 cells. The rate of internalization of these radiolabeled biomolecules was found to be time-dependent. Also, it was found that there was no long-term retention of the radioactive metabolites into the cells. Tissue distribution of the radiopeptides was evaluated in normal mice and in prostate cancer experimental models. Significant uptake of radioactivity was observed in the pancreas of PC-3 tumor-bearing SCID mice. Dynamic studies of both radiopeptides showed satisfactory tumor images.

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Trends in NMR chemical shifts and ligand mobility of TcO(V) and ReO(V) complexes with aminothiols

Cited by 15 publications

References 24 publications

A Phenylbenzothiazole Conjugate with the Tricarbonyl fac‐[M(I)(CO)₃]⁺ (M = Re, ⁹⁹Tc, ^99mTc) Core for Imaging of β‐Amyloid Plaques

A Phenylbenzothiazole Conjugate with the Tricarbonyl fac‐[M(I)(CO)₃]⁺ (M = Re, ⁹⁹Tc, ^99mTc) Core for Imaging of β‐Amyloid Plaques

⁹⁹Tc NMR as a promising technique for structural investigation of biomolecules: theoretical studies on the solvent and thermal effects of phenylbenzothiazole complex

Structural Assessment and Biological Evaluation of Two N₃S Bombesin Derivatives

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Trends in NMR chemical shifts and ligand mobility of TcO(V) and ReO(V) complexes with aminothiols

Cited by 15 publications

References 24 publications

A Phenylbenzothiazole Conjugate with the Tricarbonyl fac‐[M(I)(CO)3]+ (M = Re, 99Tc, 99mTc) Core for Imaging of β‐Amyloid Plaques

A Phenylbenzothiazole Conjugate with the Tricarbonyl fac‐[M(I)(CO)3]+ (M = Re, 99Tc, 99mTc) Core for Imaging of β‐Amyloid Plaques

99Tc NMR as a promising technique for structural investigation of biomolecules: theoretical studies on the solvent and thermal effects of phenylbenzothiazole complex

Structural Assessment and Biological Evaluation of Two N3S Bombesin Derivatives

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A Phenylbenzothiazole Conjugate with the Tricarbonyl fac‐[M(I)(CO)₃]⁺ (M = Re, ⁹⁹Tc, ^99mTc) Core for Imaging of β‐Amyloid Plaques

A Phenylbenzothiazole Conjugate with the Tricarbonyl fac‐[M(I)(CO)₃]⁺ (M = Re, ⁹⁹Tc, ^99mTc) Core for Imaging of β‐Amyloid Plaques

⁹⁹Tc NMR as a promising technique for structural investigation of biomolecules: theoretical studies on the solvent and thermal effects of phenylbenzothiazole complex

Structural Assessment and Biological Evaluation of Two N₃S Bombesin Derivatives