Synthesis and characterization of monooxorhenium(V) complexes of mercaptoacetylglycylglycylglycine. Crystal structure of tetrabutylammonium oxo(mercaptoacetylglycylglycylglycine)rhenate(V)

Rao, T. Nageswara; Adhikesavalu, D.; Camerman, Arthur; Fritzberg, Alan R.

doi:10.1016/s0020-1693(00)83066-2

Cited by 30 publications

(17 citation statements)

References 13 publications

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“…Comparison of the above complexes with those derived from N,NЈ-bis[o-(diphenylphosphino)phenyl]propane-1,3-diamine 22 shows that the phosphine group provides the oxorhenium() core with an amount of electron density similar to that from a thioether sulfur, an inference that can be justified by looking at the electron density demand at the position trans to Re᎐ ᎐ O, as shown by the different substituents bound to this position. For example, the density offered to the central Re V ᎐ ᎐ O core by the third amido nitrogen in [ReO(L)] Ϫ (L = sulfanylacetyltriglycinate) 23 is insufficient. So, the thioether sulfur must co-ordinate as thiolate with reductive deprotection of the sulfur atom.…”

Section: Discussionmentioning

confidence: 99%

Rhenium complexes with phosphine-containing peptides. Synthesis and characterization of oxorhenium(V) complexes with N-{N -[3-(diphenylphosphino)propionyl]glycyl}-L-S -benzylcysteine and its methyl ester

Santimaria¹,

Mazzi²,

Gatto³

et al. 1997

J. Chem. Soc., Dalton Trans.

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The co-ordination of dipeptides modified with a phosphine group to the Re=O3+ core has been studied, and the new donor sets PN2X (X = O or S) achieved. N-{N-[3-(Diphenylphosphino)propionyl]glycy}-L-S-benzylcysteine (H3L2) and its methyl ester derivative (H2L1) have been used for preparing six-co-ordinated oxorhenium(V) complexes, providing a new chelating system for targeting Re-186/188 to protein bioactive molecules. The complexes have been characterized by means of UV/VIS, IR, FAB and H-1 NMR spectroscopy. The crystal structures of [ReO(L-2)(OH2)]. H2O . MeOH and [ReO(L-1)Cl] have been established. In both the complexes the co-ordination geometry is distorted octahedral. The ligands are tetradentate, co-ordinating the Re=O3+ moiety through the phosphine phosphorus, the two deprotonated amide nitrogens and the O or S atom from the carboxylate or thioether groups. When the cysteine carboxylic moiety is free, it can replace, in organic solvents, the thioether sulfur to give a stable complex, the fourth donor atom in the equatorial plane being a carboxylate oxygen. In basic medium [ReO(L-1)Cl] underwent substitution of Cl- by OH-, evidence for the high stability of the PN2S donor set

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Section: Discussionmentioning

confidence: 99%

Rhenium complexes with phosphine-containing peptides. Synthesis and characterization of oxorhenium(V) complexes with N-{N -[3-(diphenylphosphino)propionyl]glycyl}-L-S -benzylcysteine and its methyl ester

Santimaria¹,

Mazzi²,

Gatto³

et al. 1997

J. Chem. Soc., Dalton Trans.

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“…[11] The rhenium precursor oxorhenium citrate was generated in situ by a known method. [12] High-performance liquid chromatography (HPLC) was conducted on a Waters 600 Millennium Chromatography System coupled to both a Waters 991 photodiode array detector (UV trace for 99g Tc, Re, and ligands) and a GABI gamma detector from Raytest (g trace for 99m Tc). Separations were achieved on a C 18 RP column eluted with a binary gradient system at a 1.0 mL min À1 flow rate.…”

Section: Methodsmentioning

confidence: 99%

“…For the technetium tracer ( 99m Tc) both types of complexes are also formed, as indicated by HPLC studies, with the ratio between [ 99m TcO(L n )(L) 3 ] and [ 99m TcO(L n )(L) 2 ] greatly dependent on the concentration of ligands in the reaction mixture. synthesis of the complexes was based on ligand exchange reactions with [ReOCl 3 (PPh 3 ) 2 ], [10] rhenium(v) gluconate, [11] or rhenium(v) citrate [12] as precursors (Experimental Section, Methods A ± C) in the presence of an equimolar quantity of the bidentate ligand L n H and an excess of monodentate thiol LH (molar ratio of Re-precursor/L n H/LH 1:1:3). Rhenium(v) citrate and rhenium(v) gluconate were used in situ as formed by reduction of ReO 4 À by Sn II .…”

mentioning

confidence: 99%

Novel Oxorhenium and Oxotechnetium Complexes from an Aminothiol[NS]/Thiol[S] Mixed-Ligand System

et al. 2001

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The simultaneous action of a bidentate aminothiol ligand, LnH, (n = 1: (CH3CH2)2NCH2CH2SH and n = 2: C5H10NCH2CH2SH) and a monodentate thiol ligand, LH (LH: p-methoxythiophenol) on a suitable MO (M = Re, 99gTc) precursor results in the formation of complexes of the general formula [MO(Ln)(L)3] (1, 2 for Re and 5. 6 for 99gTc). In solution these complexes gradually transform to [MO(Ln)(L)2] complexes (3, 4 for Re and 7, 8 for 99gTc). The transformation is much faster for oxotechnetium than for oxorhenium complexes. Complexes 1-4, 7, and 8 have been isolated and fully characterized by elemental analysis and spectroscopic methods. Detailed NMR assignments were made for complexes 3, 4, 7, and 8. X-ray studies have demonstrated that the coordination geometry around rhenium in complex 1 is square pyramidal (tau = 0.06), with four sulfur atoms (one from the L1H ligand and three from three molecules of p-methoxythiophenol) in the basal plane and the oxo group in the apical position. The L1H ligand acts as a monodentate ligand with the nitrogen atom being protonated and hydrogen bonded to the oxo group. The four thiols are deprotonated during complexation resulting in a complex with an overall charge of zero. The coordination geometry around rhenium in complex 4 is trigonally distorted square pyramidal (tau = 0.41), while in the oxotechnetium complex 7 it is square pyramidal (tau = 0.16). In both complexes LnH acts as a bidentate ligand. The NS donor atom set of the bidentate ligand and the two sulfur atoms of the two monodentate thiols define the basal plane, while the oxygen atom occupies the apical position. At the technetium tracer level (99mTc), both types of complexes, [99mTcO(Ln)(L)3] and [99mTcO(Ln)(L)2], are formed as indicated by HPLC. At high ligand concentrations the major complex is [99mTcO(Ln)(L)3], while at low concentrations the predominant complex is [99mTcO(Ln)(L)2]. The complexes [99mTcO(Ln)(L)3] transform to the stable complexes [99mTcO(Ln)(L)2]. This transformation is much faster in the absence of ligands. The complexes [99mTcO(Ln)(L)2] are stable, neutral, and also the predominant product of the reaction when low concentrations of ligands are used, a fact that is very important from the radiopharmaceutical point of view.

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“…The synthesis of AEBS-MAG 2 (5) thiol and 3 amide functional groups with 99m Tc, to form a stable technetium(V)oxo core [28]. The crude reaction mixture was purified using RP-HPLC and 99m Tc-8 was obtained with an overall radiochemical yield of 65% and a radiochemical purity of !98% (n ¼ 3).…”

Section: Chemistry and Radiolabelling Of Aebs-magmentioning

confidence: 99%

“…The formation of the complex of rhenium with the BAT analogue 2 proceeded in two steps. In a first step the precursor TBA[ReOCl 4 ] was synthesized as reported earlier [28]. Briefly, under stirring, HCl gas was bubbled slowly through a solution of TBA[ReO 4 ] (tetrabutylammonium perrhenate, 2.2 mmol, 1.1 g) in ethanol (20 mL).…”

Section: Synthesis Of Complex Of 2 With Rhenium (Re-3)mentioning

confidence: 99%

Development and biological evaluation of 99mTc-sulfonamide derivatives for in vivo visualization of CA IX as surrogate tumor hypoxia markers

Akurathi

Dubois

Celen

et al. 2014

European Journal of Medicinal Chemistry

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In vivo visualization of tumor hypoxia related markers, such as the endogenous transmembrane protein CA IX may lead to novel therapeutic and diagnostic applications in the management of solid tumors. In this study 4-(2-aminoethyl)benzene sulfonamide (AEBS, K(i) = 33 nM for CA IX) has been conjugated with bis(aminoethanethiol) (BAT) and mercaptoacetyldiglycine (MAG2) tetradendate ligands and the conjugates radiolabelled with (99m)Tc, to obtain anionic and neutral (99m)Tc-labeled sulfonamide derivatives, respectively. The corresponding rhenium analogues were also prepared and showed good inhibitory activities against hCA IX (K(i) = 59-66 nM). In addition, a second generation bis AEBS was conjugated with MAG2 and labeled with (99m)Tc, and the obtained diastereomers were also evaluated in targeting CA IX. Biodistribution studies in mice bearing HT-29 colorectal xenografts revealed a maximum tumor uptake of <0.5% ID/g at 0.5 h p.i for all the tracers. In vivo radiometabolite analysis indicated that at 1 h p.i. MAG₂ tetradendate ligands were more stable in plasma (>50% intact) compared to the neutral complex (28% intact). This preliminary data suggest that negatively charged (99m)Tc-labeled sulfonamide derivatives with modest lipophilicity and longer circulation time could be promising markers to target CA IX.

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Synthesis and characterization of monooxorhenium(V) complexes of mercaptoacetylglycylglycylglycine. Crystal structure of tetrabutylammonium oxo(mercaptoacetylglycylglycylglycine)rhenate(V)

Cited by 30 publications

References 13 publications

Rhenium complexes with phosphine-containing peptides. Synthesis and characterization of oxorhenium(V) complexes with N-{N -[3-(diphenylphosphino)propionyl]glycyl}-L-S -benzylcysteine and its methyl ester

Rhenium complexes with phosphine-containing peptides. Synthesis and characterization of oxorhenium(V) complexes with N-{N -[3-(diphenylphosphino)propionyl]glycyl}-L-S -benzylcysteine and its methyl ester

Novel Oxorhenium and Oxotechnetium Complexes from an Aminothiol[NS]/Thiol[S] Mixed-Ligand System

Development and biological evaluation of 99mTc-sulfonamide derivatives for in vivo visualization of CA IX as surrogate tumor hypoxia markers

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