Study of the Signal Structure to Assess the Human Coordination Ability

Author(s):  
Polina G. Zhurbilo ◽  
Pavel G. Korolev ◽  
Alexey Yu. Kurochkin ◽  
Dmitrii S. Zayko ◽  
Alexandr A. Nikitin
2019 ◽  
Vol 16 (3) ◽  
pp. 444-448 ◽  
Author(s):  
Biyun Su ◽  
Yaning Li ◽  
Dandan Pan ◽  
Paison Faida ◽  
Tingyu Yan ◽  
...  

Aim and Objective: The late transition metal complexes with five-membered heterocyclic mono-imine ligands have attracted much attention because of their potential application in olefin polymerization catalysis. In order to increase the coordination ability of heteroatom N and S to center metals, CH3 group was introduced into the side arm of pyrrole imine and thiophene imine respectively, to get two series of novel five-membered heterocyclic imine compounds, mono(imino)pyrroles and mono(imino)thiophenes Materials and Methods: Two series of novel five-membered heterocyclic compounds with the mono-imine group were synthesized from the p-toluene sulfonic acid catalyzed Schiff base condensation of aromatic amines and 2-acetylpyrrole/ 2-acetylthiophene respectively, using CH3 group to substitute the common H atom on the side arm of pyrrole imine/ thiophene imine. Results: All the heterocyclic mono-imine compounds were characterized adequately by means of 1H NMR, 13C NMR, FT-IR, elementary analysis, as well as X-ray crystallographic diffraction. The reactivity differences between two precursor 2-acetylpyrrole and 2-acetylthiophene with aromatic amines were compared and discussed in detail. Conclusion: Compared to traditional heating methods, the solvent-free microwave irradiation seemed more efficient to prepare these series of five-membered heterocyclic mono-imine compounds, which resulted in a higher yield and cleaner product.


Author(s):  
Hua Yang ◽  
Feng Gao ◽  
Brooke McNeil ◽  
Chengcheng Zhang ◽  
Zheliang Yuan ◽  
...  

Abstract Background 64Cu is one of the few radioisotopes that can be used for both imaging and therapy, enabling theranostics with identical chemical composition. Development of stable chelators is essential to harness the potential of this isotope, challenged by the presence of endogenous copper chelators. Pyridyl type chelators show good coordination ability with copper, prompting the present study of a series of chelates DOTA-xPy (x = 1–4) that sequentially substitute carboxyl moieties with pyridyl moieties on a DOTA backbone. Results We found that the presence of pyridyl groups significantly increases 64Cu labeling conversion yield, with DOTA-2Py, −3Py and -4Py quantitatively complexing 64Cu at room temperature within 5 min (1 × 10− 4 M). [64Cu]Cu-DOTA-xPy (x = 2–4) exhibited good stability in human serum up to 24 h. When challenged with 1000 eq. of NOTA, no transmetallation was observed for all three 64Cu complexes. DOTA-xPy (x = 1–3) were conjugated to a cyclized α-melanocyte-stimulating hormone (αMSH) peptide by using one of the pendant carboxyl groups as a bifunctional handle. [64Cu]Cu-DOTA-xPy-αMSH retained good serum stability (> 96% in 24 h) and showed high binding affinity (Ki = 2.1–3.7 nM) towards the melanocortin 1 receptor. Conclusion DOTA-xPy (x = 1–3) are promising chelators for 64Cu. Further in vivo evaluation is necessary to assess the full potential of these chelators as a tool to enable further theranostic radiopharmaceutical development.


Molecules ◽  
2021 ◽  
Vol 26 (2) ◽  
pp. 439
Author(s):  
Monika Rzonsowska ◽  
Katarzyna Kozakiewicz ◽  
Katarzyna Mituła ◽  
Julia Duszczak ◽  
Maciej Kubicki ◽  
...  

A synthesis of a series of mono-T8 and difunctionalized double-decker silsesquioxanes bearing substituted triazole ring(s) has been reported within this work. The catalytic protocol for their formation is based on the copper(I)-catalyzed azide-alkyne cycloaddition (CuAAC) process. Diverse alkynes were in the scope of our interest—i.e., aryl, hetaryl, alkyl, silyl, or germyl—and the latter was shown to be the first example of terminal germane alkyne which is reactive in the applied process’ conditions. From the pallet of 15 compounds, three of them with pyridine-triazole and thiophenyl-triazole moiety attached to T8 or DDSQ core were verified in terms of their coordinating properties towards selected transition metals, i.e., Pd(II), Pt(II), and Rh(I). The studies resulted in the formation of four SQs based coordination compounds that were obtained in high yields up to 93% and their thorough spectroscopic characterization is presented. To our knowledge, this is the first example of the DDSQ-based molecular complex possessing bidentate pyridine-triazole ligand binding two Pd(II) ions.


2004 ◽  
Vol 2004 (9) ◽  
pp. 1817-1826 ◽  
Author(s):  
Olivier Sénèque ◽  
Morgane Campion ◽  
Michel Giorgi ◽  
Yves Le Mest ◽  
Olivia Reinaud

1980 ◽  
Vol 46 ◽  
pp. 29-34 ◽  
Author(s):  
G. Formicka-Kozłowska ◽  
H. Kozłowska ◽  
G. Kupryszewski

2017 ◽  
Vol 21 (02) ◽  
pp. 135-143
Author(s):  
Tatyana N. Lomova ◽  
Maxim S. Filatov ◽  
Mikhail K. Islyaikin

Polydentate ligand-bornane[2,3-b]pyrazino-fused [30]trithiadodecaazahexaphyrin has been synthesized by crossover condensation of the racemic mixture of (R/S)-bornane[2[Formula: see text],3[Formula: see text]-b]-2,3-dicyanopyrazine and 2,5-diamino-1,3,4-thiadiazole. Its coordination ability, acid-base behavior and stability were studied by chemical kinetics/thermodynamics, UV-vis spectrophotometry and quantum chemical DFT/B3LYP/6-31G(d,p) methods. The fourth-order kinetic equation with the kinetic constant of 3.38 × 108 s[Formula: see text].mol3.L[Formula: see text] and the association mechanism according to the Langford−Gray classification were established for the fused [30]trithiadodecaazahexaphyrin–nickel diacetate–DMF system. The stepwise protonation of macrocyclic ligand with p[Formula: see text] of -1.41 in CH2Cl2-CF3COOH mixtures at the Hammett acidity functions ([Formula: see text] changed from -2.0 to 2.0 and quantitative parameters of ligand stability in AcOH–H2SO4 mixtures was obtained. The chemical structure of protonated forms and ligand destruction mechanism have been proposed. The obtained results are of interest for development of technological regulations of complex formation and for the transition to the hetero nuclear complexes.


Catalysts ◽  
2018 ◽  
Vol 8 (8) ◽  
pp. 337 ◽  
Author(s):  
Yanhe You ◽  
Juan Luo ◽  
Jianwei Xie ◽  
Jinli Zhang ◽  
Bin Dai

This article investigated the effect of three nitrogen-containing carboxylic acid ligands for the Nieuwland catalyst system. The catalyst system containing 4.5% N-(2-acetamido) iminodiacetic acid exhibited improved catalytic activity with excellent performance. The yield of monovinylacetylene (MVA) was maintained at 36.7% after 24 h, which was increased by 17.1% relative to the Nieuwland catalyst system. Based on a variety of analyses on the crystals precipitated from the catalyst solutions, it can be inferred that the outstanding performance and lifetime of the catalysts were related to the abilities of these ligands to form strong coordination with Cu+ ions and stabilize them.


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