TY - JOUR A1 - Walther, M. A1 - Jung, C. M. A1 - Bergmann, R. A1 - Pietzsch, J. A1 - Rode, K. A1 - Fahmy, K. A1 - Mirtschink, P. A1 - Stehr, S. A1 - Heintz, A. A1 - Wunderlich, G. A1 - Kraus, Werner A1 - Pietzsch, H.-J. A1 - Kropp, J. A1 - Deussen, A. A1 - Spies, H. T1 - Synthesis and Biological Evaluation of a New Type of 99mTechnetium-Labeled Fatty Acid for Myocardial Metabolism Imaging PY - 2007 SN - 1043-1802 SN - 1520-4812 VL - 18 SP - 216 EP - 230 CY - Washington, DC AN - OPUS4-14514 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mirtschink, P. A1 - Stehr, S.N. A1 - Pietzsch, H.J. A1 - Bergmann, R. A1 - Pietzsch, J. A1 - Wunderlich, G. A1 - Heintz, A.C. A1 - Kropp, J. A1 - Spies, H. A1 - Kraus, Werner A1 - Deussen, A. A1 - Walther, M. T1 - Modified "4+1" Mixed Ligand Technetium-Labeled Fatty Acids for Myocardial Imaging: Evaluation of Myocardial Uptake and Biodistribution N2 - Our group previously synthesized 99mTc-labeled fatty acids suitable for myocardial metabolism and flow imaging. In this set of experiments, 29 new analogues were synthesized according to the “4 + 1” mixed ligand approach with some specific differences. Conventional “4 + 1” 99mTc-fatty acids are built in the sequence: Tc-chelate, alkyl chain, and carboxylic group. We developed compounds following a new design with the sequence: carboxylic group, alkyl chain, Tc-chelate, and lipophilic tail. Therefore, the 99mTc-chelate was transferred to a more central position of the compound, aiming toward an improved myocardial profile and an accelerated liver clearance. In this context, several functional groups incorporated in the lipophilic tail section were tested to evaluate their influence on the compound's character. In addition to biodistribution studies in vivo, the myocardial first-pass extraction of the compounds was tested in an isolated Langendorff rat heart model. A satisfactory myocardial uptake of up to 20% of the injected dose (% ID) in the perfused heart and a fast liver clearance in vivo with only 0.29% ID/g at 60 min postinjection demonstrate that the induced molecular modifications affect the kinetics of 99mTc-radiolabeled fatty acid compounds favorably. From the data set, rules for estimating the biodistribution of fatty acids tracers are deduced. PY - 2008 DO - https://doi.org/10.1021/bc700164c SN - 1043-1802 SN - 1520-4812 VL - 19 IS - 1 SP - 97 EP - 108 CY - Washington, DC AN - OPUS4-16499 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Tisato, F. A1 - Refosco, F. A1 - Porchia, M. A1 - Bolzati, C. A1 - Bandoli, G. A1 - Dolmella, A. A1 - Duatti, A. A1 - Boschi, A. A1 - Jung, C. M. A1 - Pietzsch, H.-J. A1 - Kraus, Werner T1 - The Crucial Role of the Diphosphine Heteroatom X in the Stereochemistry and Stabilization of the Substitution-Inert [M(N)(PXP)]2+ Metal Fragments (M = Tc, Re; PXP = Diphosphine Ligand) N2 - The nature of the heteroatom X incorporated in the five-membered PXP-diphosphine bridging chain was found to play a primary unit role both in the overall stability and in the stereochemical arrangement of nitrido-containing [M(N)(PXP)]2+ metal fragments (M = Tc, Re). Thus, by mixing PXP ligands with labile [Re(N)Cl4]- and Tc(N)Cl2(PPh3)2 nitrido precursors in CH2Cl2/MeOH mixtures, a series of neutral M(N)Cl2(PXP) complexes (M = Tc, 1-5; M = Re, 8, 9) was collected. In the resulting distorted octahedrons, PXP adopted facial or meridional coordination, and combination with halide co-ligands produced three different stereochemical arrangements, that is, fac,cis, mer,cis, and mer,trans, depending primarily on the nature of the diphosphine heteroatom X. When X = NH, mer,cis-Tc(N)Cl2(PNP1), 1, was the only isomer formed. Alternatively, when a tertiary amine nitrogen (X = NR; R = CH3, CH2CH2OCH3) was introduced in the bridging chain, fac,cis-M(N)Cl2(PN(R)P) complexes (M = Tc, 2, 3; M = Re, 8f) were obtained. Isomerization into the mer,cis-Re(N)Cl2(PN(R)P), 8m, species was observed only in the case of rhenium when the tertiary amine group carried the less encumbering methyl substituent. fac,cis-Tc(N)Cl2(PSP), 4f, was isolated in the solid state when X = S, but a mixture of fac,cis-Tc(N)Cl2(PSP) and mer,trans-Tc(N)Cl2(PSP), 4m, isomers was found in equilibrium in the solution state. A similar equilibrium between fac,cis-M(N)Cl2(POP) (M = Tc, 5f; M = Re, 9f) and mer,trans-M(N)Cl2(POP) (M = Tc, 5m; M = Re, 9m) species was detected in POP-containing complexes. The molecular structure of all of these complexes was assessed by means of conventional physicochemical techniques including multinuclear NMR spectroscopy and X-ray diffraction analysis of representative mer,cis-Tc(N)Cl2(PN(H)P), 1, fac,cis-Tc(N)Cl2(PSP), 4f, and mer,cis-Re(N)Cl2(PN(Me)P), 8m, compounds. PY - 2004 DO - https://doi.org/10.1021/ic049139r SN - 0020-1669 SN - 1520-510X VL - 43 IS - 26 SP - 8617 EP - 8625 PB - American Chemical Society CY - Washington, DC AN - OPUS4-5546 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Mironov, Y.V. A1 - Shestopalov, M.A. A1 - Brylev, K.A. A1 - Yarovoi, S. S. A1 - Romanenko, G.V. A1 - Fedorov, V.E. A1 - Spies, H. A1 - Pietzsch, H.-J. A1 - Stephan, H. A1 - Geipel, G. A1 - Bernhard, G. A1 - Kraus, Werner T1 - [Re6Q7O(3,5-Me2PzH)6]Br2.3,5-Me2PzH (Q = S, Se) - New Octahedral Rhenium Cluster Complexes with Organic Ligands: Original Synthetic Approach and Unexpected Ligand Exchange in the Cluster Core KW - Rhenium KW - Cluster compounds KW - Ligand exchange KW - Organic ligands KW - Structure elucidation KW - Laser fluorescence spectroscopy PY - 2005 SN - 1434-1948 SN - 1099-0682 SP - 657 EP - 661 PB - Wiley-VCH Verl. CY - Weinheim AN - OPUS4-7039 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schiller, E. A1 - Kraus, Werner A1 - Reck, Günter A1 - Spies, H. A1 - Pietzsch, H.-J. T1 - [2-Carboxy-2,2',2''-nitrilotris(ethanethiolato)-kappa4N,S,S',S''](triphenyl-phosphine-kappaP)rhenium(III) acetone solvate N2 - The title compound, [Re(C7H12NO2S3)(C18H15P)]·C3H6O, crystallizes from a solution in chloro­form–acetone–cyclo­­hexane with enantiomers disordered equally over each mol­ecular site. Hydrogen bonds between the carbox­yl groups form dimers in the crystal structure. PY - 2005 DO - https://doi.org/10.1107/S1600536805018660 SN - 1600-5368 VL - 61 IS - 7 SP - m1373 EP - m1375 PB - Munksgaard CY - Copenhagen AN - OPUS4-7613 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Schiller, E. A1 - Seifert, S. A1 - Tisato, F. A1 - Refosco, F. A1 - Kraus, Werner A1 - Spies, H. A1 - Pietzsch, H.-J. T1 - Mixed-Ligand Rhenium-188 Complexes with Tetradentate/Monodentate NS3/P ('4 + 1') Coordination: Relation of Structure with Antioxidation Stability N2 - Development of new radiopharmaceuticals based on rhenium-188 depends on finding appropriate ligands able to give complexes with high in vivo stability. Rhenium(III) mixed-ligand complexes with tetradentate/monodentate ('4 + 1') coordination of the general formula [Re(NS3)(PRR'R' ')] (NS3 = tris(2-mercaptoethyl)amine and derivatives thereof, PRR'R' ' = phosphorus(III) ligands) appear to be among the promising tools to achieve this goal. According to this approach, we synthesized and characterized a series of rhenium model complexes. In vitro stabilities of the corresponding rhenium-188 complexes were determined by incubating 2-3 MBq or alternatively 37 MBq of the complexes in phosphate buffer, human plasma, and rat plasma, respectively, at 22° C or 37° C, followed by checking the amount of 188ReO4- formed after 1 h, 24, and 48 h by thin-layer chromatography. The rate of perrhenate formation varied over a wide range, depending primarily on the nature of the phosphorus(III) ligand. Physicochemical parameters of the corresponding nonradioactive rhenium complexes were analyzed in detail to find out the factors influencing their different stability and furthermore to design new substitution-inert '4 + 1' complexes. Tolman's cone angle of phosphorus(III) ligands and the lipophilic character of the inner coordination sphere were found to be crucial factors to build up stable rhenium '4 + 1' complexes. Additional information useful to describe electronic and steric properties of these compounds were selected from electronic spectra (wavelength of the ReS charge-transfer band), cyclovoltammetric measurements (E° of the ReIII/ReIV couple), and NMR investigations (31P chemical shift of coordinated P(III) ligands). PY - 2005 UR - http://pubs.acs.org/cgi-bin/abstract.cgi/bcches/2005/16/i03/abs/bc049745a.html SN - 1043-1802 SN - 1520-4812 VL - 16 IS - 3 SP - 634 EP - 643 CY - Washington, DC AN - OPUS4-7547 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pietzsch, H.-J. T1 - Novel technetium(III) mixed-ligand chelates for the design of lipophilic complexes stabl in vivo T2 - 14. Internationale Symposium on Radiopharm. Chem. CY - Interlaken, Switzerland DA - 2001-06-10 PY - 2001 AN - OPUS4-2959 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Heinrich, T.K. A1 - Kraus, Werner A1 - Pietzsch, H.-J. A1 - Smuda, C. A1 - Spies, H. T1 - Novel Rhenium Chelate System Derived from Dimercaptosuccinic Acid for the Selective Labeling of Biomolecules N2 - This work is part of an effort to develop chelating agents for stable binding and easy conjugation of Re-188 to biologically interesting structures. Starting from the well-known in vivo stability of [188ReO(DMSA)2]-, we want to exploit this coordination system for the design of 188ReO(V) chelates, which are stable toward reoxidation to perrhenate and toward ligand exchange under all conditions of radiopharmaceutical development. Therefore, a new type of tetradentate ligand has been synthesized by bridging two molecules of N,N'-diisobutyl-2,3-dimercaptosuccinamide with N-(3-aminopropyl)propane-1,3-diamine. The resulting stereoisomeric tetrathiolato S4 ligand of composition (iBu)2N(O)C-C(SH)-C(SH)-C(O)NH-(CH2)3-NH-(CH2)3-NHC(O)-C(SH)-C(SH)-C(O)N(iBu)2 forms anionic five-coordinate oxorhenium(V) complexes by a ligand-exchange reaction of NBu4[ReOCl4] in methanol. In the absence of a base, the compounds were isolated as "betaine", [ReO(S4)], with the protonated nitrogen of the bridge serving as an internal "counterion". Two representatives have been fully characterized in both the solid and solution states and found to adopt the expected square-pyramidal coordination geometry. The equatorial plane is formed by four thiolate sulfur atoms, whereas the oxygen occupies the apical position. The orientation of the metal oxo group is exo in relation to the carbamido groups in both isomers. Both complexes are stereoisomeric regarding the junction of the triamine chain. PY - 2005 DO - https://doi.org/10.1021/ic051148s SN - 0020-1669 SN - 1520-510X VL - 44 IS - 26 SP - 9930 EP - 9937 PB - American Chemical Society CY - Washington, DC AN - OPUS4-12507 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - JOUR A1 - Kraus, Werner A1 - Walther, M. A1 - Jung, C. M. A1 - Emmerling, Franziska A1 - Pietzsch, H.-J. T1 - Bromotricarbonyl{15-[2-(methylsulfanyl)ethylsulfanyl]pentadecanoic acid-kappa2S,S'}rhenium(I) N2 - The title compound, [ReBr(C18H36O2S2)(CO)3], was synthesized and characterized as a non-radioactive surrogate of a novel Tc-containing fatty acid derivative prepared according to the tricarbonyl/dithioether design with the objective of developing new Tc-based radiopharmaceuticals for the non-invasive diagnosis of myocardial metabolism. The Re chelate contains the metal in the oxidation state +1 and is attached to the terminal position of a fatty acid. The complex formation was accomplished by a ligand exchange reaction using [NBu4]2[Re(CO)3Br3] as starting material. KW - Fatty acid KW - Tc-compound KW - Radio-pharmaceutical PY - 2006 DO - https://doi.org/10.1107/S1600536806024081 SN - 1600-5368 VL - 62 IS - 7 SP - m1660 EP - m1662 PB - Munksgaard CY - Copenhagen AN - OPUS4-12529 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER - TY - CONF A1 - Pietzsch, H.-J. T1 - Rhenium complexes of demercaptosuccinic acid derivatives for targeted radiotherapy T2 - 37th. International Conference on Coordination Chemistry CY - Cape Town, South Africa DA - 2006-08-13 PY - 2006 AN - OPUS4-13817 LA - eng AD - Bundesanstalt fuer Materialforschung und -pruefung (BAM), Berlin, Germany ER -