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Matthias Tacke - One of the best experts on this subject based on the ideXlab platform.

  • Synthesis and Cytotoxicity Studies of Silyl-Substituted Titanocene Dichloride Derivatives
    Organometallics, 2012
    Co-Authors: Anthony Deally, Frauke Hackenberg, Grainne Lally, Helge Müller-bunz, Matthias Tacke
    Abstract:

    Six new Titanocene compounds have been isolated and characterized. These compounds were synthesized from their silyl-substituted fulvene or cyclopentadiene precursors using Super Hydride (LiBEt3H) or n-BuLi, followed by transmetalation with titanium tetrachloride, to yield the corresponding Titanocene Dichloride derivatives. These complexes are bis-[((phenyl)dimethylsilane)cyclopentadienyl] titanium(IV) Dichloride (3a), bis-[((4-methoxyphenyl)dimethylsilane)cyclopentadienyl] titanium(IV) Dichloride (3b), bis-[((4-N,N-dimethylmethanamine)dimethylsilane)cyclopentadienyl] titanium(IV) Dichloride (3c), bis-[((4-N,N-diethylmethanamine)dimethylsilane)cyclopentadienyl] titanium(IV) Dichloride (3d), bis-[((1-methyl-5-trimethylsilyl)indol-3-yl)methylcyclopentadienyl] titanium(IV) Dichloride (4e), and bis-[((1-methyl-3-diethylaminomethyl-5-trimethylsilyl)indol-2-yl)methylcyclopentadienyl] titanium(IV) Dichloride (4f). The two Titanocenes 3a and 3b were crystallized and characterized by X-ray crystallography, while ...

  • Synthesis and Biological Evaluation of Achiral Indole-Substituted Titanocene Dichloride Derivatives
    International journal of medicinal chemistry, 2012
    Co-Authors: Anthony Deally, Frauke Hackenberg, Grainne Lally, Matthias Tacke
    Abstract:

    Six new Titanocene compounds have been isolated and characterised. These compounds were synthesised from their fulvene precursors using Super Hydride (LiBEt3H) followed by transmetallation with titanium tetrachloride to yield the corresponding Titanocene Dichloride derivatives. These complexes are bis-[((1-methyl-3-diethylaminomethyl)indol-2-yl)methylcyclopentadienyl] titanium (IV) Dichloride (5a), bis-[((5-methoxy-1-methyl,3-diethylaminomethyl)indol-2-yl)methylcyclopentadienyl] titanium (IV) Dichloride (5b), bis-[((1-methyl,3-diethylaminomethyl)indol-4-yl)methylcyclopentadienyl] titanium (IV) Dichloride (5c), bis-[((5-bromo-1-methyl)indol-3-yl)methylcyclopentadienyl] titanium (IV) Dichloride (5d), bis-[((5-chloro-1-methyl)indol-3-yl)methylcyclopentadienyl] titanium (IV) Dichloride (5e), and bis-[((5-fluoro-1-methyl)indol-3-yl)methylcyclopentadienyl] titanium (IV) Dichloride (5f). All six Titanocenes 5a–5f were tested for their cytotoxicity through MTT-based in vitro tests on CAKI-1 cell lines using DMSO and Soluphor P as solubilising agents in order to determine their IC50 values. Titanocenes 5a–5f were found to have IC50 values of 10 (±2), 21 (±3), 29 (±4), 140 (±6), and 450 (±10) μM when tested using DMSO.

  • Synthesis and Cytotoxicity Studies of Silyl-Substituted Titanocene Dichloride Derivatives
    2012
    Co-Authors: Anthony Deally, Frauke Hackenberg, Grainne Lally, Helge Müller-bunz, Matthias Tacke
    Abstract:

    Six new Titanocene compounds have been isolated and characterized. These compounds were synthesized from their silyl-substituted fulvene or cyclopentadiene precursors using Super Hydride (LiBEt3H) or n-BuLi, followed by transmetalation with titanium tetrachloride, to yield the corresponding Titanocene Dichloride derivatives. These complexes are bis-[((phenyl)­dimethylsilane)­cyclopentadienyl] titanium­(IV) Dichloride (3a), bis-[((4-methoxyphenyl)­dimethylsilane)­cyclopentadienyl] titanium­(IV) Dichloride (3b), bis-[((4-N,N-dimethylmethanamine)­dimethylsilane)­cyclopentadienyl] titanium­(IV) Dichloride (3c), bis-[((4-N,N-diethylmethanamine)­dimethylsilane)­cyclopentadienyl] titanium­(IV) Dichloride (3d), bis-[((1-methyl-5-trimethylsilyl)­indol-3-yl)­methylcyclopentadienyl] titanium­(IV) Dichloride (4e), and bis-[((1-methyl-3-diethylaminomethyl-5-trimethylsilyl)­indol-2-yl)­methylcyclopentadienyl] titanium­(IV) Dichloride (4f). The two Titanocenes 3a and 3b were crystallized and characterized by X-ray crystallography, while all six Titanocenes were tested for their cytotoxicity through MTT-based in vitro tests on CAKI-1 cell lines in order to determine their IC50 values. Titanocenes were found to have IC50 values of 139 (±5), 106 (± 4), 127 (±4), 104 (±9), 90 (±6), and 15 (±2) μM

  • Effects of Titanocene Dichloride derivatives on prostate cancer cells, specifically DNA damage-induced apoptosis.
    The Prostate, 2010
    Co-Authors: Sandra Cuffe, James Claffey, Matthias Tacke, Catherine M. Dowling, Clara Pampillón, Megan Hogan, John M. Fitzpatrick, Michael P. Carty, R. William G. Watson
    Abstract:

    BACKGROUND While locally advanced prostate cancer is initially treatable with androgen ablation, eventually cells develop a castrate-resistant phenotype. Currently, there are no effective treatments for this form of the disease with Docetaxel only providing a small survival advantage. In this study, the effects of novel derivatives of Titanocene Dichloride on prostate cancer cell lines has been investigated. METHODS Cellular effects were assessed using the crystal violet assay and the clonogenic survival assay. Cell cycle and apoptosis were assessed by propidium iodide staining. DNA damage was analyzed by comet assay and Western analysis. DNA damage response inhibition was achieved by pre-incubation with an ATM/ATR inhibitor; CGK733 and DNA-PK inhibitor; DMNB. RESULTS These analogs caused a reduction in cell number. In particular Titanocene Y and C had significant effects in all cell lines. A reduction in clonogenic survival was found in response to Titanocene Y in three cell lines while the PC-3 cells exhibited increased resistance.Further analysis showed no effect on cell cycle however, the analogs were found to induce apoptosis in a dose-dependent manner in all cell lines. These analogs associate with DNA, induce DNA damage and a differential damage response. Inhibition of key regulators of this DNA damage response sensitized the PC-3 cell line to Titanocene-induced apoptosis and significantly reduced the clonogenic capacity of the cells. CONCLUSION These results demonstrate the mechanism of action of these novel Titanocene Dichloride analogs and their potential use in castrate-independent advanced prostate cancer. Prostate 71: 111–124, 2011. © 2010 Wiley-Liss, Inc.

  • Benzyl-substituted Titanocene Dichloride anticancer drugs: From lead to hit
    Journal of Organometallic Chemistry, 2010
    Co-Authors: James Claffey, Helge Müller-bunz, Matthias Tacke
    Abstract:

    Abstract Through the reaction of Super Hydride (LiBEt3H) with 6-phenyl-substituted fulvenes followed by transmetallation to TiCl4 ten novel benzyl-substituted Titanocene Dichloride derivatives were synthesised. 6(4-morpholinomethyl-phenyl) fulvene (6g) and (bis-[(4-methoxymethyl-benzyl)cyclopentadienyl]titanium(IV) Dichloride) (8a) were characterised by single crystal X-ray diffraction. All of the Titanocenes had their cytotoxicity investigated through preliminary in vitro testing on the LLC-PK (pig kidney epithelial) cell line and CAKI-1 human kidney cell human carcinoma cell line in an MTT based assay in order to determine their IC50 values. The Titanocenes synthesised were found to have IC50 values ranging from 2.3 (±0.3) μM (comparable to cisplatin) to others which show no anti-proliferative activity on this cell line in standard DMSO formulations on LLC-PK cell line. Eight of the Titanocenes were found to be completely water-soluble and had IC50 values of 6.5 (±0.7) μM to no activity when using medium only for formulation. On the CAKI-1 cell line, IC50 values of 7.8 (±1.4) μM to no activity were found using DMSO formulation, while IC50 values of 0.55 (±0.32) μM to no activity were measured using just medium as the formulation reagent. Some of the Titanocenes show significant cytotoxicity improvement when compared directly to the lead compound Titanocene Y (bis-[(p-methoxybenzyl)cyclopentadienyl] titanium(IV) Dichloride) and are more cytotoxic than cisplatin. Bis-[(4-diethylaminomethyl-benzyl)cyclopentadienyl]titanium(IV) Dichloride (8d) at this preliminary stage seems to be the most promising of the ten compounds prepared and exhibits nanomolar activity against CAKI-1.

Dominique Harakat - One of the best experts on this subject based on the ideXlab platform.

  • Carbosilane Metallodendrimers with Titanocene Dichloride End Groups
    Organometallics, 2012
    Co-Authors: Tomáš Strašák, Florian Jaroschik, Jan Sykora, Jiří Horský, Zuzana Walterová, Jan Cermak, Dominique Harakat
    Abstract:

    Carbosilane metallodendrimers containing substituted Titanocene Dichloride end groups were prepared using hydrosilylation as the capping reaction. Two complementary pathways were followed: hydrosilylation of ω-alkenyl-substituted Titanocene Dichloride complexes with Si–H bond terminated dendrimers and hydrosilylation of vinyl terminated dendritic materials with 3-(dimethylsilyl)propyl-substituted Titanocene Dichloride. The former procedure provided dendrimers of the first generation with four end units and of the second generation with eight end units. The latter method gave dendrititic wedges and dendrimers up to the second generation with 16 peripheral Titanocene Dichloride units and molecular weight 7070 Da. Dendritic materials were purified by GPC and characterized by MALDI-TOF mass spectrometry and ESI-TOF mass spectrometry (metallodendrimers) and also by multinuclear NMR.

  • Carbosilane Metallodendrimers with Titanocene Dichloride End Groups
    Organometallics, 2012
    Co-Authors: Tomáš Strašák, Florian Jaroschik, Jan Sykora, Jiří Horský, Zuzana Walterová, Jan Čermák, Dominique Harakat
    Abstract:

    Carbosilane metallodendrimers containing substituted Titanocene Dichloride end groups were prepared using hydrosilylation as the capping reaction. Two complementary pathways were followed: hydrosil...

  • Carbosilane Metallodendrimers with Titanocene Dichloride End Groups
    2012
    Co-Authors: Tomáš Strašák, Florian Jaroschik, Jan Čermák, Jan Sýkora, Jiří Horský, Zuzana Walterová, Dominique Harakat
    Abstract:

    Carbosilane metallodendrimers containing substituted Titanocene Dichloride end groups were prepared using hydrosilylation as the capping reaction. Two complementary pathways were followed: hydrosilylation of ω-alkenyl-substituted Titanocene Dichloride complexes with Si–H bond terminated dendrimers and hydrosilylation of vinyl terminated dendritic materials with 3-(dimethylsilyl)­propyl-substituted Titanocene Dichloride. The former procedure provided dendrimers of the first generation with four end units and of the second generation with eight end units. The latter method gave dendrititic wedges and dendrimers up to the second generation with 16 peripheral Titanocene Dichloride units and molecular weight 7070 Da. Dendritic materials were purified by GPC and characterized by MALDI-TOF mass spectrometry and ESI-TOF mass spectrometry (metallodendrimers) and also by multinuclear NMR

Florian Jaroschik - One of the best experts on this subject based on the ideXlab platform.

  • Reduction of Titanocene Dichloride with dysprosium: access to a stable Titanocene(II) equivalent for phosphite-free Takeda carbonyl olefination
    Dalton Transactions, 2015
    Co-Authors: Guillaume Bousrez, Ingrid Dechamps, Jean-luc Vasse, Florian Jaroschik
    Abstract:

    The reduction of Titanocene Dichloride with dysprosium yields a new Titanocene(II) equivalent without the need for further stabilising ligands. This reagent can be employed in combination with dithioacetals for the olefination of different carbonyl groups and allows for a simplified all-in-one procedure.

  • Carbosilane Metallodendrimers with Titanocene Dichloride End Groups
    Organometallics, 2012
    Co-Authors: Tomáš Strašák, Florian Jaroschik, Jan Sykora, Jiří Horský, Zuzana Walterová, Jan Cermak, Dominique Harakat
    Abstract:

    Carbosilane metallodendrimers containing substituted Titanocene Dichloride end groups were prepared using hydrosilylation as the capping reaction. Two complementary pathways were followed: hydrosilylation of ω-alkenyl-substituted Titanocene Dichloride complexes with Si–H bond terminated dendrimers and hydrosilylation of vinyl terminated dendritic materials with 3-(dimethylsilyl)propyl-substituted Titanocene Dichloride. The former procedure provided dendrimers of the first generation with four end units and of the second generation with eight end units. The latter method gave dendrititic wedges and dendrimers up to the second generation with 16 peripheral Titanocene Dichloride units and molecular weight 7070 Da. Dendritic materials were purified by GPC and characterized by MALDI-TOF mass spectrometry and ESI-TOF mass spectrometry (metallodendrimers) and also by multinuclear NMR.

  • Carbosilane Metallodendrimers with Titanocene Dichloride End Groups
    Organometallics, 2012
    Co-Authors: Tomáš Strašák, Florian Jaroschik, Jan Sykora, Jiří Horský, Zuzana Walterová, Jan Čermák, Dominique Harakat
    Abstract:

    Carbosilane metallodendrimers containing substituted Titanocene Dichloride end groups were prepared using hydrosilylation as the capping reaction. Two complementary pathways were followed: hydrosil...

  • Carbosilane Metallodendrimers with Titanocene Dichloride End Groups
    2012
    Co-Authors: Tomáš Strašák, Florian Jaroschik, Jan Čermák, Jan Sýkora, Jiří Horský, Zuzana Walterová, Dominique Harakat
    Abstract:

    Carbosilane metallodendrimers containing substituted Titanocene Dichloride end groups were prepared using hydrosilylation as the capping reaction. Two complementary pathways were followed: hydrosilylation of ω-alkenyl-substituted Titanocene Dichloride complexes with Si–H bond terminated dendrimers and hydrosilylation of vinyl terminated dendritic materials with 3-(dimethylsilyl)­propyl-substituted Titanocene Dichloride. The former procedure provided dendrimers of the first generation with four end units and of the second generation with eight end units. The latter method gave dendrititic wedges and dendrimers up to the second generation with 16 peripheral Titanocene Dichloride units and molecular weight 7070 Da. Dendritic materials were purified by GPC and characterized by MALDI-TOF mass spectrometry and ESI-TOF mass spectrometry (metallodendrimers) and also by multinuclear NMR

Tomáš Strašák - One of the best experts on this subject based on the ideXlab platform.

  • Carbosilane Metallodendrimers with Titanocene Dichloride End Groups
    Organometallics, 2012
    Co-Authors: Tomáš Strašák, Florian Jaroschik, Jan Sykora, Jiří Horský, Zuzana Walterová, Jan Cermak, Dominique Harakat
    Abstract:

    Carbosilane metallodendrimers containing substituted Titanocene Dichloride end groups were prepared using hydrosilylation as the capping reaction. Two complementary pathways were followed: hydrosilylation of ω-alkenyl-substituted Titanocene Dichloride complexes with Si–H bond terminated dendrimers and hydrosilylation of vinyl terminated dendritic materials with 3-(dimethylsilyl)propyl-substituted Titanocene Dichloride. The former procedure provided dendrimers of the first generation with four end units and of the second generation with eight end units. The latter method gave dendrititic wedges and dendrimers up to the second generation with 16 peripheral Titanocene Dichloride units and molecular weight 7070 Da. Dendritic materials were purified by GPC and characterized by MALDI-TOF mass spectrometry and ESI-TOF mass spectrometry (metallodendrimers) and also by multinuclear NMR.

  • Carbosilane Metallodendrimers with Titanocene Dichloride End Groups
    Organometallics, 2012
    Co-Authors: Tomáš Strašák, Florian Jaroschik, Jan Sykora, Jiří Horský, Zuzana Walterová, Jan Čermák, Dominique Harakat
    Abstract:

    Carbosilane metallodendrimers containing substituted Titanocene Dichloride end groups were prepared using hydrosilylation as the capping reaction. Two complementary pathways were followed: hydrosil...

Mary L.s. Queiroz - One of the best experts on this subject based on the ideXlab platform.

  • The effect of a Titanocene Dichloride derivative, Ti IV (C5H5)2 NCS2, on the haematopoietic response of Ehrlich tumour-bearing mice
    European Journal of Pharmacology, 2002
    Co-Authors: Marize Campos Valadares, Mary L.s. Queiroz
    Abstract:

    Abstract The effects of the [Ti IV (C5H5)2 NCS2] metallocene (BCDT), a Titanocene Dichloride derivative, on the growth and differentiation of granulocyte-macrophage progenitor cells [colony-forming unit-granulocyte-macrophage (CFU-GM)] and bone marrow cellularity in normal and Ehrlich ascites tumour-bearing mice were studied. As expected for the Ehrlich ascites tumour-model, concomitant myelosuppression, increased number of spleen CFU-GM and changes in bone marrow cellularity were observed. The treatment of Ehrlich ascites tumour-bearing mice with BCDT (10–30 mg/kg/day) produced a dose-dependent increase in myelopoiesis, a reduction in splenic colonies and a restoration in the total and differential marrow cell counts. We also observed an increase in CFU-GM number when bone marrow cells obtained from normal mice were incubated in vitro with serum from normal mice treated with BCDT. In addition, BCDT prolonged, in a dose-dependent manner, the survival of mice inoculated with Ehrlich ascites tumour. Although it has been previously reported that substitutions in the two halides of the Titanocene do not interfere with antitumoural effect, our results with BCDT demonstrated a reduction in antitumour efficacy when compared to previous results with the original Titanocene produced in our laboratory.