23 research outputs found
Strong Cytotoxicity of Organometallic Platinum Complexes with Alkynyl Ligands
The synthesis, spectroscopy, structures,
and chemical reactivity
of the organometallic complexes [(COD)ÂPtÂ(CîźCR)<sub>2</sub>]
and [(COD)ÂPtÂ(CîźCR)Â(Râ˛)] (COD = 1,5-cyclooctadiene, R
= Ph, (Me)ÂPh (2Me, 3Me, or 4Me), (NO<sub>2</sub>)ÂPh (2NO<sub>2</sub>, 3NO<sub>2</sub>, or 4NO<sub>2</sub>), (4F)ÂPh, (4OMe)ÂPh, 2Py (2-pyridyl);
RⲠ= Me (methyl), Neop (neopentyl = 2,2-dimethyl-1-methyl),
NeoSi (neosilyl = trimethylsilylmethyl), Bz (benzyl)) has been explored.
The crystal structures reveal square-planar surroundings of the Pt
atoms with short PtâCÂ(alkynyl) bonds (<2 Ă
) and almost
perpendicular orientation of the CîźCâaryl group to the
Pt coordination plane. Nonattractive ĎâĎ stacking
and CâH¡¡¡F intermolecular interactions were
observed in the crystal structures. Multinuclear (<sup>1</sup>H, <sup>13</sup>C, <sup>195</sup>Pt, and <sup>19</sup>F) NMR spectroscopy
reveals structures in solution and Ptâligand bond strength.
The thermal stability in organic solvents, the electrochemical stability,
and the reactivity of the complexes in organic or aquatic (water-containing)
solution toward the physiologically relevant species glutathione,
chloride, and protons was tested, revealing remarkable stability or
inertness of the complexes. Cytotoxicity experiments in HT-29 colon
carcinoma and MCF-7 breast adenocarcinoma cell lines revealed highly
promising activities for selected platinum alkynyl COD complexes
Strong Cytotoxicity of Organometallic Platinum Complexes with Alkynyl Ligands
The synthesis, spectroscopy, structures,
and chemical reactivity
of the organometallic complexes [(COD)ÂPtÂ(CîźCR)<sub>2</sub>]
and [(COD)ÂPtÂ(CîźCR)Â(Râ˛)] (COD = 1,5-cyclooctadiene, R
= Ph, (Me)ÂPh (2Me, 3Me, or 4Me), (NO<sub>2</sub>)ÂPh (2NO<sub>2</sub>, 3NO<sub>2</sub>, or 4NO<sub>2</sub>), (4F)ÂPh, (4OMe)ÂPh, 2Py (2-pyridyl);
RⲠ= Me (methyl), Neop (neopentyl = 2,2-dimethyl-1-methyl),
NeoSi (neosilyl = trimethylsilylmethyl), Bz (benzyl)) has been explored.
The crystal structures reveal square-planar surroundings of the Pt
atoms with short PtâCÂ(alkynyl) bonds (<2 Ă
) and almost
perpendicular orientation of the CîźCâaryl group to the
Pt coordination plane. Nonattractive ĎâĎ stacking
and CâH¡¡¡F intermolecular interactions were
observed in the crystal structures. Multinuclear (<sup>1</sup>H, <sup>13</sup>C, <sup>195</sup>Pt, and <sup>19</sup>F) NMR spectroscopy
reveals structures in solution and Ptâligand bond strength.
The thermal stability in organic solvents, the electrochemical stability,
and the reactivity of the complexes in organic or aquatic (water-containing)
solution toward the physiologically relevant species glutathione,
chloride, and protons was tested, revealing remarkable stability or
inertness of the complexes. Cytotoxicity experiments in HT-29 colon
carcinoma and MCF-7 breast adenocarcinoma cell lines revealed highly
promising activities for selected platinum alkynyl COD complexes
A RuthenoceneâPNA Bioconjugate î¸ Synthesis, Characterization, Cytotoxicity, and AAS-Detected Cellular Uptake
Labeling of peptide nucleic acids (PNA) with metallocene
complexes
is explored herein for the modulation of the analytical characteristics,
as well as biological properties of PNA. The synthesis of the first
ruthenoceneâPNA conjugate with a dodecamer, mixed-sequence
PNA is described, and its properties are compared to a ferrocene-labeled
analogue as well as an acetylated, metal-free derivative. The synthetic
characteristics, chemical stability, analytical and thermodynamic
properties, and the interaction with cDNA were investigated. Furthermore,
the cytotoxicity of the PNA conjugates is determined on HeLa, HepG2,
and PT45 cell lines. Finally, the cellular uptake of the metal-containing
PNAs was quantified by high-resolution continuum source atomic absorption
spectrometry (HR-CS AAS). An unexpectedly high cellular uptake to
final concentrations of 4.2 mM was observed upon incubation with 50
ÎźM solutions of the ruthenoceneâPNA conjugate. The ruthenocene
label was shown to be an excellent label in all respects, which is
also more stable than its ferrocene analogue. Because of its high
stability, low toxicity, and the lack of a natural background of ruthenium,
it is an ideal choice for bioanalytical purposes and possible medicinal
and biological applications like, e.g., the development of gene-targeted
drugs
Metallocene-Modified Uracils: Synthesis, Structure, and Biological Activity
A new
family of metalloceneâuracil conjugates, including
[3-(<i>N</i>1-uracilyl)-1-(ferrocenyl)]Âpropene (<b>2c</b>), [3-(<i>N</i>1-thyminyl)-1-(ferrocenyl)]Âpropene (<b>3c</b>), [3-(<i>N</i>1-(5-fluorouracilyl))-1-(ferrocenyl)]Âpropene
(<b>4c</b>), and [3-(<i>N</i>1-uracilyl)-1-(ruthenocenyl)]Âpropene
(<b>5c</b>), was obtained in three steps from (3-chloropropionyl)Âferrocene
and (3-chloropropionyl)Âruthenocene, respectively. The complexes <b>2c</b>â<b>5c</b> and their intermediates <b>2a</b>â<b>5a</b> and <b>2b</b>â<b>5b</b> were characterized by NMR and infrared spectroscopy, mass spectrometry,
and elemental analysis. The molecular structures of the intermediates <b>2b</b> and <b>4a</b> were determined by single-crystal X-ray
structure analysis. In the solid state, two molecules of <b>2b</b> or <b>4a</b> form a dimeric structure, which is held together
by strong hydrogen bonds. Compounds <b>2c</b>â<b>5c</b> were also studied by cyclic voltammetry (CV). The ferrocenylâuracil
derivatives <b>2c</b>â<b>4c</b> revealed reversible
uncomplicated oxidations, whereas the cyclic voltammogram of the ruthenocenyl
derivative <b>5c</b> showed an irreversible oxidation. Compounds <b>2c</b>â<b>5c</b> were tested for their antiproliferative
activity against human MCF-7 breast adenocarcinoma and HT-29 colon
carcinoma cells. Compounds <b>3c</b>â<b>5c</b> were
moderately active against MCF-7 cancerous cells. Atomic absorption
spectroscopy measurements on compound <b>5c</b> revealed that
the ruthenocenyl derivative is taken up by HT-29 cells in a time-dependent
manner. However, the ruthenium cellular level remains relatively low.
Compounds <b>2a</b>â<b>5a</b> were also tested
against Gram-positive methicillin-sensitive Staphylococcus
aureus (MSSA), methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant Staphylococcus aureus (VRSA) and Staphylococcus
epidermidis bacterial strains. Compound <b>4a</b> showed significant antibacterial activity against all bacterial
strains, while compounds <b>2a</b> and <b>3b</b> were
only moderately active. No antibacterial activity was found for the
ruthenocenyl derivative <b>5a</b>
Results of a docking experiment with 8a in CLK1 (PDB-ID: 1Z57).
<p>A: front view; B: top view; dashed lines: H-bonds and edge to face interaction.</p
In vitro growth inhibition of cancer cell lines by KuWal151 (8c)<sup>a</sup>.
<p>In vitro growth inhibition of cancer cell lines by KuWal151 (8c)<a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0196761#t002fn001" target="_blank"><sup>a</sup></a>.</p
CLK1 inhibitors described in the literature.
<p>TG003 (<b>1</b>); NCGC00185963 (<b>2</b>), KH-CB19 (<b>3</b>); benzo[<i>b</i>]thiophen-2-carboxamide <b>4</b>; T3 (<b>5</b>); TG693 (<b>6</b>); [1,2,3]triazolo[4,5-<i>c</i>]quinoline <b>7</b>.</p
3-Aryl-6,7-dihydropyrrolo[3,4-<i>g</i>]indol-8(1<i>H</i>)-ones listed in Table 1.
<p>3-Aryl-6,7-dihydropyrrolo[3,4-<i>g</i>]indol-8(1<i>H</i>)-ones listed in <a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0196761#pone.0196761.t001" target="_blank">Table 1</a>.</p
Molecular and Cellular Characterization of the Biological Effects of Ruthenium(II) Complexes Incorporating 2âPyridyl-2-pyrimidine-4-carboxylic Acid
A great majority of the Ru complexes currently studied
in anticancer
research exert their antiproliferative activity, at least partially,
through ligand exchange. In recent years, however, coordinatively
saturated and substitutionally inert polypyridyl RuÂ(II) compounds
have emerged as potential anticancer drug candidates. In this work,
we present the synthesis and detailed characterization of two novel
inert RuÂ(II) complexes, namely, [RuÂ(bipy)<sub>2</sub>(Cpp-NH-Hex-COOH)]<sup>2+</sup> (<b>2</b>) and [RuÂ(dppz)<sub>2</sub>(CppH)]<sup>2+</sup> (<b>3</b>) (bipy = 2,2â˛-bipyridine; CppH = 2-(2â˛-pyridyl)Âpyrimidine-4-carboxylic
acid; Cpp-NH-Hex-COOH = 6-(2-(pyridin-2-yl)Âpyrimidine-4-carboxamido)Âhexanoic
acid; dppz = dipyridoÂ[3,2-<i>a</i>:2â˛,3â˛-<i>c</i>]Âphenazine). <b>3</b> is of particular interest as
it was found to have IC<sub>50</sub> values comparable to cisplatin,
a benchmark standard in the field, on three cancer cell lines and
a better activity on one cisplatin-resistant cell line than cisplatin
itself. The mechanism of action of <b>3</b> was then investigated
in detail and it could be demonstrated that, although <b>3</b> binds to calf-thymus DNA by intercalation, the biological effects
that it induces did not involve a nuclear DNA related mode of action.
On the contrary, confocal microscopy colocalization studies in HeLa
cells showed that <b>3</b> specifically targeted mitochondria.
This was further correlated by ruthenium quantification using High-resolution
atomic absorption spectrometry. Furthermore, as determined by two
independent assays, <b>3</b> induced apoptosis at a relatively
late stage of treatment. The generation of reactive oxygen species
could be excluded as the cause of the observed cytotoxicity. It was
demonstrated that the mitochondrial membrane potential in HeLa was
impaired by <b>3</b> as early as 2 h after its introduction
and even more with increasing time
Molecular and Cellular Characterization of the Biological Effects of Ruthenium(II) Complexes Incorporating 2âPyridyl-2-pyrimidine-4-carboxylic Acid
A great majority of the Ru complexes currently studied
in anticancer
research exert their antiproliferative activity, at least partially,
through ligand exchange. In recent years, however, coordinatively
saturated and substitutionally inert polypyridyl RuÂ(II) compounds
have emerged as potential anticancer drug candidates. In this work,
we present the synthesis and detailed characterization of two novel
inert RuÂ(II) complexes, namely, [RuÂ(bipy)<sub>2</sub>(Cpp-NH-Hex-COOH)]<sup>2+</sup> (<b>2</b>) and [RuÂ(dppz)<sub>2</sub>(CppH)]<sup>2+</sup> (<b>3</b>) (bipy = 2,2â˛-bipyridine; CppH = 2-(2â˛-pyridyl)Âpyrimidine-4-carboxylic
acid; Cpp-NH-Hex-COOH = 6-(2-(pyridin-2-yl)Âpyrimidine-4-carboxamido)Âhexanoic
acid; dppz = dipyridoÂ[3,2-<i>a</i>:2â˛,3â˛-<i>c</i>]Âphenazine). <b>3</b> is of particular interest as
it was found to have IC<sub>50</sub> values comparable to cisplatin,
a benchmark standard in the field, on three cancer cell lines and
a better activity on one cisplatin-resistant cell line than cisplatin
itself. The mechanism of action of <b>3</b> was then investigated
in detail and it could be demonstrated that, although <b>3</b> binds to calf-thymus DNA by intercalation, the biological effects
that it induces did not involve a nuclear DNA related mode of action.
On the contrary, confocal microscopy colocalization studies in HeLa
cells showed that <b>3</b> specifically targeted mitochondria.
This was further correlated by ruthenium quantification using High-resolution
atomic absorption spectrometry. Furthermore, as determined by two
independent assays, <b>3</b> induced apoptosis at a relatively
late stage of treatment. The generation of reactive oxygen species
could be excluded as the cause of the observed cytotoxicity. It was
demonstrated that the mitochondrial membrane potential in HeLa was
impaired by <b>3</b> as early as 2 h after its introduction
and even more with increasing time