294-90-6Relevant articles and documents
Preparation and animal biodistribution of 166Ho labeled DOTA for possible use in intravascular radiation therapy (IVRT)
Das, Tapas,Chakraborty, Sudipta,Banerjeel, Sharmila,Samuel, Grace,Sarma,Venkatesh, Meera,Pillai
, p. 197 - 209 (2003)
Owing to its favorable decay characteristics (T1/2 = 27 h, Eβ(max) = 1.85 MeV, Eγ = 81 keV) and its availability with a specific activity of 3.74.4GBq/mg from a moderate flux reactor, 166Ho can be considered as a potential radionuclide for intravascular radiation therapy (IVRT) using liquid-filled balloons. In the present work, studies on the use of 166Ho labeled 1,4,7,10- tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA) as a possible agent for IVRT for the prevention of restenosis has been initiated. 166Ho was obtained by irradiating natural Ho2O3 powder and DOTA was synthesized by a multistep procedure. The optimum protocol of radiolabeling of DOTA with 166Ho was achieved by varying different reaction parameters. The complex was found to retain its stability for 7 days at room temperature. Bioevaluation studies carried out in Wistar rats showed that >95% of the injected activity was excreted within 3 h p.i. with almost no retention in any major organ. Both radiochemical and biological studies showed that 166Ho labeled DOTA can be further explored as a potential agent for IVRT. Copyright
Isomerization kinetics of lanthanide(III) complexes with the pendant-arm macrocyclic ligand 1,4,7,10-tetrakis(2-hydroxyethyl)-1,4,7,10-tetraazacyclododecane
Pittet, Pierre-Andre,Frueh, Dominique,Tissieres, Veronique,Buenzli, Jean-Claude G.
, p. 895 - 900 (1997)
The 13C and 1H NMR spectra of the complexes of LaIII, EuIII and LuIII with 1,4,7,10-tetrakis(2-hydroxyethyl)-1,4,7,10-tetraazacyclododecane (L1) in acetonitrile or methanol indicated the presence of two enantiomers the interconversion of which proceeds through both a ring inversion and a rearrangement of the pendant arms. The following kinetic parameters were extracted from temperature-dependent 13C NMR spectra for the ring inversion in [LaL1]3+, [EuL1]3+, [LuL1]3+ in CD3OD and [EuL1]3+ in CD3CN:k(298 K) = 1396, 1055, 1288 and 880 s-1; ΔH? = 37.6, 41.1, 48.2 and 47.7 kJ mol-1; ΔS? = -58.5, -49.2, -23.8 and -28.4 J K-1 mol-1, respectively. The lanthanide(III) substitution induces a continuous variation of the kinetic parameters, implying the same pathway for the enantiomerization. The behaviour of [LnL1]3+ in solution is compared with that of complexes with similar 12-membered tetraaza macrocycles bearing pendant arms.
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Kossai,R. et al.
, p. 1059 - 1062 (1979)
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A microcalorimetric determination of the enthalpies of formation in solution of nickel(II) complexes with tetraaza macrocyclic ligands of varying size
Fabbrizzi, Luigi,Micheloni, Mauro,Paoletti, Piero
, p. 535 - 538 (1980)
The enthalpies of formation of nickel complexes with tetraaza macrocyclic ligands of varying ring size, from 12 to 15 members, have been determined by destroying the complexes in aqueous solution with alkaline cyanide. The octahedral-square-planar equilibria have been investigated, and the results are presented as ΔH° for both octahedral, blue and, when possible, square-planar, yellow species. Like the Cu(II) system, the blue, octahedral series exhibits a maximum in ΔH° with [14]aneN4. This is discussed in terms of the relative size of the ligand and the metal ion. The unexpected reversal of ΔH° for the two square-planar complexes is rationalized in terms of expected ligand transformations.
DINUCLEATING LIGAND OR DINUCLEAR METAL COMPLEX
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Paragraph 0058-0059, (2021/03/19)
To provide a metal complex that has high cancer cell toxicity and has DNA target and cyclen.SOLUTION: The present disclosure provides a dinuclear metal complex represented by the following formula (IV).SELECTED DRAWING: None
Preparation method of cyclen
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Paragraph 0061; 0062; 0063, (2020/02/14)
The invention provides a preparation method of cyclen. The method comprises the following step: taking triethylenetetramine (TETA) as a raw material to carry out refining, then carrying out a reactionon the refined triethylenetetramine with methylglyoxal to obtain an intermediate 2, carrying out cyclization on the intermediate 2 with glyoxal, carrying out reducing with sodium borohydride to obtain a cyclized intermediate 3, finally carrying out ring opening through acid hydrolysis, and then adjusting the pH value by using an alkali solution to free out the cyclen.
Novel synthesis method of 1, 4, 7, 10-tetraazacyclododecane
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, (2020/11/01)
The invention provides a novel synthesis method of 1, 4, 7, 10-tetraazacyclododecane. The 1, 4, 7, 10-tetraazacyclododecane has important application in biomedicine and molecular biology, molecular recognition, catalysis, enzyme chemistry, supramolecular chemistry, hydrogen storage materials and other main surfaces. The preparation method comprises the following steps of: reacting triethylene tetramine and urea serving as initial raw materials to generate ethylene bis-imidazolinone (hereinafter referred to as bis-imidazolinone), carrying out condensation reaction on the raw material and 1, 2-dihalogenated ethane to generate 1, 4-keto-7, 10-keto-1, 4, 7, 10-tetraazacyclododecan (hereinafter referred to as diketone cyclododecane), and preparing 1, 4, 7, 10-tetraazacyclododecane by hydrolysis. According to the method, the product with the gas chromatography content of 99% or above is obtained at the highest total yield of 74.97%. The method has the advantages of high atom utilization rate, few reaction steps, simplicity, easiness in control, high yield and the like, and is a new process route representing clean and efficient production.