Dichloro(ethylenediamine)platinum(II)

Ellis, Leanne T.; Hambley, T. W.

doi:10.1107/s0108270194006840

Cited by 15 publications

(9 citation statements)

References 2 publications

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“…Also present in the lattice are short intermolecular Pt–Pt interactions (Figure 2, right), marked by a Pt–Pt distance of 3.30 Å. The X-ray crystal structure of the analogous compound, [Pt(en)Cl 2 ] (en = ethylenediamine), has been determined for two distinct polymorphs [42, 43]. A careful crystal packing analysis of these polymorphs revealed close Pt–Pt intermolecular interactions, similar to those observed for 1 .…”

Section: Resultsmentioning

confidence: 99%

“…A careful crystal packing analysis of these polymorphs revealed close Pt–Pt intermolecular interactions, similar to those observed for 1 . In the orthorhombic form [42], the Pt–Pt separation is 3.38 Å, whereas the Pt–Pt separation in the triclinic polymorph [43] is 3.42 Å. These Pt–Pt interactions are supported by hydrogen bonds between the chloride ligands and coordinated amine protons of the neighboring molecules.…”

Section: Resultsmentioning

confidence: 99%

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Modulation of ligand fluorescence by the Pt(II)/Pt(IV) redox couple

Wilson

Lippard

2012

Inorganica Chimica Acta

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The dangling carboxylic acid moiety of the known platinum(II) complex, [Pt(edma)Cl2] (edma = ethylenediaminemonoacetic acid), was functionalized via amide coupling chemistry with benzyl amine and dansyl ethylenediamine to afford the derivatives [Pt(edBz)Cl2] (1) and [Pt(edDs)Cl2] (2). Subsequent oxidation of these platinum(II) complexes with iodobenzene dichloride in DMF yielded the respective platinum(IV) analogues, [Pt(edBz)Cl4] (3) and [Pt(edDs)Cl4] (4). All four platinum complexes were characterized by multinuclear NMR spectroscopy, IR spectroscopy, electrospray ionization mass spectrometry, and elemental analysis. In addition, compounds 1 and 3 were structurally characterized by X-ray crystallography. The photophysical properties of the compounds bearing the fluorescent dansyl moiety, 2 and 4, were evaluated. The emission quantum yields of 2 and 4 in DMF are 27% and 1.6%, respectively. This large difference in emission efficiency indicates that the platinum(IV) center in 4 is more effective at quenching the dansyl-based fluorescence than the platinum(II) center in 2. Time-dependent density functional theory calculations indicate that 4 has several low-lying singlet excited states that energetically lie below the primary radiation-accessible excited state of the dansyl fluorophore. These low-energy excited states may offer non-radiative decay pathways that lower the overall emission quantum yield. Treatment of 4 with biologically relevant reducing agents in pH 7.4 phosphate-buffered saline induces a 6.3-fold increase in emission intensity. These results demonstrate that 4 and future derivatives thereof may be useful for imaging the reduction of platinum(IV) complexes in living systems, chemistry of importance for future platinum-based anticancer drug strategies.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Modulation of ligand fluorescence by the Pt(II)/Pt(IV) redox couple

Wilson

Lippard

2012

Inorganica Chimica Acta

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“…The structure of the coordination sphere was derived from that of cis-[dichlorideethylenediamineplatinum(II)], 39 replacing one of the -NH 2 protons with the methylene group of the spacer. The resulting structure was energy-minimized in the Amber force field using a steepest descent algorithm, leaving the platinum coordination geometry unchanged.…”

Section: Structure Optimization By Molecular Mechanics (Mm)mentioning

confidence: 99%

Synthesis and characterisation of estrogenic carriers for cytotoxic Pt(ii) fragments: biological activity of the resulting complexes

et al. 2005

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This paper describes the synthesis and the spectroscopic characterisation of cis-dichloro[N-(4-(17alpha-ethynylestradiolyl)-benzyl)-ethylenediamine]platinum(II) and cis-diamino[2-(4-(17alpha-ethynylestradiolyl)-benzoylamino)-malonato]platinum(II). These complexes were synthesised in good yield according to multi-step procedures based on the classical and non-classical Sonogashira coupling reaction, respectively. These compounds retain an acceptable degree of relative binding affinity (RBA) for the alpha form of estrogen receptor. Combined treatment of breast cancer cell lines, namely hormone-sensitive MCF-7 and hormone-insensitive MDA-MB-231 cell lines, indicates that these compounds maintain agonistic activity so that the potential advantage in vehiculation of the cytotoxic moiety by means of the receptor system is counteracted by the proliferative effect of the estrogenic component of the entire molecule, especially at low concentrations.

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“…10,58 Our objective in the present study was to assess the properties of cis-1,4-diaminocyclohexane (cis-1,4-DACH) by determining the effect of the carrier ligand on the formation, stability, and stereochemistry of (cis-1,4-DACH)Pt(ss-oligo) adducts. An interesting feature of this ligand is its ∼97°bite angle, 65 which is larger than that of cisplatin (∼90°; Chart 2) and of analogous compounds with ethylenediamine (en, 83°) 66 or 1,2-DACH (83.2°, average value of three Pt complexes). 67 The large bite angle of cis-1,4-DACH complexes could also reduce the (amine)NH 2 -Pt-N7(G) angles, thus possibly influencing the distribution of conformers and likely diminishing the ease of interconversion between possible conformers.…”

Section: Introductionmentioning

confidence: 94%

DNA fragment conformations in adducts with Kiteplatin

et al. 2015

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The anticancer activity of cisplatin is triggered by its formation of intrastrand adducts involving adjacent G residues of DNA. To obtain information on the different conformers that can be formed, carrier ligands such as 2,2'-bipiperidine, which provide large steric bulk near the platinum coordination plane and decrease the dynamic motion about the Pt-N7 bonds, were introduced ("retro-modelling" approach). In the present study we investigate the effect of cis-1,4-diaminocyclohexane (cis-1,4-DACH) on the formation, stability, and stereochemistry of (cis-1,4-DACH)Pt(ss-oligo) adducts (ss-oligo = d(GpG) with 3'-and/or 5'-substituents). Interesting features of this ligand, absent in previous retro-modelling studies, include the large bite angle (expected to impede the ease of interconversion between possible conformers), the presence of two protons on each nitrogen (a characteristic associated with antitumor activity), and the absence of chiral centres. The use of cis-1,4-DACH has made it possible to detect different conformers in a system containing a primary diamine carrier ligand associated with anticancer activity and to confirm the previous hypothesis that the coexistence of different conformers established in studies of retro models having relatively bulky ligands is not an artefact resulting from carrier-ligand bulk. Moreover, the data for the (cis-1,4-DACH)Pt(d(GpG)) and (cis-1,4-DACH)Pt(d(GGTTT)) adducts indicate that at a temperature close to the physiological one (40°C) HH1 and ΔHT1 conformers are present in comparable amounts. In contrast, at low temperature (close to 0°C) the equilibrium shifts dramatically toward the more stable HH1 conformer (for the (cis-1,4-DACH)Pt(d(TGGT)) adduct the HH1 conformer is always dominant, even at high temperature). Notably, (cis-1,4-DACH)PtCl 2 (Kiteplatin) has been recently reinvestigated and found to be particularly active against colorectal cancer (including oxaliplatin-resistant phenotypes).

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Dichloro(ethylenediamine)platinum(II)

Cited by 15 publications

References 2 publications

Modulation of ligand fluorescence by the Pt(II)/Pt(IV) redox couple

Modulation of ligand fluorescence by the Pt(II)/Pt(IV) redox couple

Synthesis and characterisation of estrogenic carriers for cytotoxic Pt(ii) fragments: biological activity of the resulting complexes

DNA fragment conformations in adducts with Kiteplatin

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