- Rapid Thermodynamically Stable Complex Formation of [nat/111In]In3+, [nat/90Y]Y3+, and [nat/177Lu]Lu3+ with H6dappa
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A phosphinate-bearing picolinic acid-based chelating ligand (H6dappa) was synthesized and characterized to assess its potential as a bifunctional chelator (BFC) for inorganic radiopharmaceuticals. Nuclear magnetic resonance (NMR) spectroscopy was employed to investigate the chelator coordination chemistry with a variety of nonradioactive trivalent metal ions (In3+, Lu3+, Y3+, Sc3+, La3+, Bi3+). Density functional theory (DFT) calculations explored the coordination environments of aforementioned metal complexes. The thermodynamic stability of H6dappa with four metal ions (In3+, Lu3+, Y3+, Sc3+) was deeply investigated via potentiometric and spectrophotometric (UV-vis) titrations, employing a combination of acidic in-batch, joint potentiometric/spectrophotometric, and ligand-ligand competition titrations; high stability constants and pM values were calculated for all four metal complexes. Radiolabeling conditions for three clinically relevant radiometal ions were optimized ([111In]In3+, [177Lu]Lu3+, [90Y]Y3+), and the serum stability of [111In][In(dappa)]3- was studied. Through concentration-, time-, temperature-, and pH-dependent labeling experiments, it was determined that H6dappa radiolabels most effectively at near-physiological pH for all radiometal ions. Furthermore, very rapid radiolabeling at ambient temperature was observed, as maximal radiolabeling was achieved in less than 1 min. Molar activities of 29.8 GBq/μmol and 28.2 GBq/μmol were achieved for [111In]In3+ and [177Lu]Lu3+, respectively. For H6dappa, high thermodynamic stability did not correlate with kinetic inertness-lability was observed in serum stability studies, suggesting that its metal complexes might not be suitable as a BFC in radiopharmaceuticals.
- Jaraquemada-Pelaéz, Mariá De Guadalupe,Kostelnik, Thomas I.,Kubeil, Manja,Orvig, Chris,Southcott, Lily,Stephan, Holger,Wagner, Hannah K.,Wang, Xiaozhu
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p. 7238 - 7251
(2020/06/08)
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- Preparation method of N,N-dibenzyl ethylenediamine diacetate
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The invention discloses a preparation method of N,N-dibenzyl ethylenediamine diacetate. The method comprises the following steps: S1, adding 50 parts by weight of diacetyl dibenzyl ethylenediamine material into a three-necked bottle, and adding 80-120 parts by weight of concentrated hydrochloric acid into the three-necked bottle to obtain 36.0-37.5 parts by weight of a compound B; S2, adding 200 parts by weight of water into the compound B obtained in the step S1 for fully dissolving, and dropwise adding a sodium hydroxide solution to adjust the pH value to 8-9; then, adding toluene for extracting for a plurality of times, and carrying out layered treatment to obtain an organic phase of a mixture of a compound C and the toluene; S3, adding the organic phase of the mixture of the compound Cand toluene into the three-necked bottle and distilling under the reduced pressure until no fraction is obtained, then adding ethyl acetate for dissolving, heating up to 60 DEG C, then dropwise adding 20 parts by weight of glacial acetic acid, and drying to obtain 47.0-49.0 parts by weight of dibenzyl ethylenediamine diacetate finally. The preparation method provided by the invention improves thereaction safety and reduces the reaction cost; furthermore, the yield of the dibenzyl ethylenediamine diacetate is also increased to 93% or above.
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Page/Page column 8-10
(2018/10/19)
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- Synthesis and supramolecular features of hybrid POM/onium solid-state assemblies
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Polyoxomolybdate-based organic-inorganic hybrid architectures were synthesised and characterised by X-ray crystallography. The supramolecular assemblies present rows of metallic clusters H-bonded by ammonium cations, with a 1:2 molybdate/ammonium ratio. The organic moieties of the ammonium cations establish hydrophobic contact among them such as van der Waals, C-Hπ and ππ interactions that stabilise the supramolecular architectures. In particular, for compound 5 the n-alkyl tails pack closely together giving a lipid-like bilayer. In compound 6, the aromatic phenyl rings of the organic cation allow the stabilisation of the supramolecular architecture by C-Hπ and ππ interactions. Regarding the X-ray structure of the compound 11, the tetraanionic octa-molybdate [Mo8O26]4- cluster is surrounded by four ethyl-triphenyl-phosphonium cations. Running along the b-axis open channels are occupied by DMF solvent molecules. Interestingly, a soaking experiment in n-pentane with the corresponding crystals of compound 11 afforded to a crystal structure very different from the native one. Van der Waals, C-Hπ and ππ interactions between large organic moieties are fundamental in the stabilization of hybrid organic-inorganic POM architectures.
- Talotta, Carmen,Rubino, Luca,Gaeta, Carmine,Capitelli, Francesco,Saviano, Michele,Brancatelli, Giovanna,Geremia, Silvano,Vasca, Ermanno,Neri, Placido
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p. 403 - 417
(2016/04/19)
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- Synthesis and tripanocidal activity of ferrocenyl and benzyl diamines against Trypanosoma brucei and Trypanosoma cruzi
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Trypanosoma brucei and Trypanosoma cruzi are the etiologic agents of sleeping sickness and Chagas disease, respectively, two of the 17 preventable tropical infectious diseases (NTD) which have been neglected by governments and organizations working in the health sector, as well as pharmaceutical industries. High toxicity and resistance are problems of the conventional drugs employed against trypanosomiasis, hence the need for the development of new drugs with trypanocidal activity. In this work we have evaluated the trypanocidal activity of a series of N1,N2-dibenzylethane-1,2-diamine hydrochlorides (benzyl diamines) and N1-benzyl,N2-methyferrocenylethane-1,2- diamine hydrochlorides (ferrocenyl diamines) against T. brucei and T. cruzi parasite strains. We show that incorporation of the ferrocenyl group into the benzyl diamines increases the trypanocidal activity. The molecules exhibit potential trypanocidal activity in vitro against all parasite strains. Cytotoxicity assay was also carried out to evaluate the toxicity in HepG2 cells.
- Velásquez, Angela Maria Arenas,Francisco, Acácio Ivo,Kohatsu, Andréa Akiko Nakaima,Silva, Flavia Alves De Jesus,Rodrigues, Danilo Fernando,Teixeira, Rafaela Gomes Da Silva,Chiari, Bruna Galdorfini,De Almeida, Maria Gabriela José,Isaac, Vera Lucia Borges,Vargas, Maria D.,Cicarelli, Regina Maria Barretto
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p. 1707 - 1710
(2014/04/17)
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- Synthesis of N,N'-Dibenzylethylenediamine via Palladium-Carbon-catalysed Reductive Alkylation
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Reductive alkylation of ethylenediamine with benzaldehyde and hydrogen in the presence of Pd-C has been investigated in order to optimize the synthesis of N,N'-dibenzylethylenediamine; the efficiency of the procedure has been improved by minimizing undesired competing reactions of cyclization and hydrogenolysis.
- Pallavicini, Marco,Valoti, Ermanno,Piccolo, Oreste
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p. 472 - 473
(2007/10/03)
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- THE ELECTROCHEMICAL REDUCTION OF NN'-DISUBSTITUTED 6-PHENYL-2,3-DIHYDRO-1,4-DIAZEPINIUM SALTS: FORMATION OF BIS(TETRAHYDRODIAZEPINYLS) AND A DI-IMIDAZOLIDINYLBUTADIENE
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The NN'-disubstituted 6-phenyl-2,3-dihydro-1,4-diazepinium cations ( Ia-c ), in solution in dimethylformamide, undergo one electron single reduction waves at -0.9 to -1.3 V with respect to Ag-AgCl-KCl ( saturated ).The reductions were studied by polarography, cyclic voltammetry, and constant potential electrolysis.Rapid chemical reactions follow the initial reduction and isolated products were the bis(tetrahydrodiazepinyls) ( IV ) and ( VI ) and a di-imidazolidinylbutadiene ( V ).These producys were hydrolysed by concentrated hydrochloric acid to give the corresponding NN'-disubstituted ethylenediamine dihydrochloride and also, in the case of ( V ), 2,5-diphenylhexa-2,4-diene-1,6-dial.The meso-isomer ( IVa ) was converted into its racemic isomer ( IVb ) when heated in dimethylformamide.Compound ( IVb ) was quantitatively converted into the diene ( V ) in a cold mixture of chloroform and ethanol.Cyclic voltammetry studies of ( IV ) indicated that they were oxidised to bis(dihydrodiazepinium) cations, and that ( V ) was reduced, with similar behaviour to the reduction of 1,4-diphenylbuta-1,3-diene.
- Lloyd, Douglas,Vincent, Colin A.,Walton, David J.
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p. 801 - 805
(2007/10/02)
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