Mono- and bis(9-ethylguanine) complexes of trans-(CH3NH2)2PtII. X-ray structure of the 2:1 complex and redistribution of the 1:1 compound

Pesch, Ferdinand J.; Wienken, Markus; Preut, H.; Tenten, A.; Lippert, Bernhard

doi:10.1016/s0020-1693(00)84971-3

Cited by 18 publications

(10 citation statements)

References 38 publications

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“…There are two more possibilities (Figure e,f) of metalated G‘ × G·C triplexes, which have, however, no counterparts in their unmetalated forms due to the absence of suitable H-bonding interactions. In Figure e, the third G‘ is cross-linked to the G·C duplex via a N7 ‘ −M−N7 bond and the two guanine bases adopt a head − tail orientation, as found in trans -[(CH 3 NH 2 )Pt(9-EtGH) 2 ]Cl 2 , for example . The head − head orientation of the metal cross-linked G‘,G bases (Figure f) is likewise possible, as seen in model compounds obtained by us more recently .…”

Section: Resultssupporting

confidence: 65%

Metal-Modified Base Pairs Involving Different Donor Sites of Purine Nucleobases: trans-[a₂Pt(7,9-DimeG-N1)(9-EtGH-N7)]²⁺andtrans-[a₂Pt(7,9-DimeG-N1)(9-EtG-N7)]⁺(a = NH₃or CH₃NH₂; 9-EtGH = 9-Ethylguanine; 7,9-DimeG = 7,9-Dimethylguanine). Possible Relevance to Metalated DNA Triplex Structures

et al. 1999

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The X-ray crystal structures of four mixed-nucleobase complexes 1a, 1b, 2, and 4 of trans-a2PtII (a = NH3 or CH3NH2) with N1-bonded 7,9-dimethylguanine (7,9-DimeG) and N7-bonded 9-ethylguanine (9-EtGH) are reported. The compounds are discussed in terms of their possible model character for platinated nucleobase triplets of the pu × pu·pym (pu = purine, pym = pyrimidine) type and are compared with known guanine·guanine pairs. Structural differences resulting from a “metal modification” have been studied, as have been stacking and H bonding motifs. 1a and 1b are two modifications of the same compound, trans-[(NH3)2Pt(7,9-DimeG)(9-EtGH)](ClO4)2·H2O. X-ray data for 1a: orthorhombic, Pca21, a = 13.833(3) Å, b = 14.357(3) Å, c = 13.293(3) Å, Z = 4, R = 0.027. 1b: monoclinic, P21/n, a = 13.987(3) Å, b = 12.582(3) Å, c = 15.613(3) Å, β = 104.61(3)°, Z = 4, R = 0.034. trans-[(CH3NH2)2Pt(7,9-DimeG)(9-EtGH)](ClO4)2 (2): orthorhombic, Pca21, a = 13.886(1) Å, b = 14.698(1) Å, c = 13.008(3) Å, Z = 4, R = 0.034. trans-[a2Pt(7,9-DimeG)(9-EtG)](ClO4)·nH2O (3, a = NH3, n = 2; 4, a = CH3NH2, n = 3). X-ray data for 4: monoclinic, C2/c, a = 23.296(5) Å, b = 10.566(2) Å, c = 22.327(4) Å, β = 93.73(3)°, Z = 8, R = 0.047. The metalated base triplet 2·(1-MeC) (1-MeC = 1-methylcytosine) has been detected in DMSO-d 6 solution through 1H NMR spectroscopy, and an ab initio optimized structure of an analogous platinated base triplet has been obtained.

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Section: Resultssupporting

confidence: 65%

Metal-Modified Base Pairs Involving Different Donor Sites of Purine Nucleobases: trans-[a₂Pt(7,9-DimeG-N1)(9-EtGH-N7)]²⁺andtrans-[a₂Pt(7,9-DimeG-N1)(9-EtG-N7)]⁺(a = NH₃or CH₃NH₂; 9-EtGH = 9-Ethylguanine; 7,9-DimeG = 7,9-Dimethylguanine). Possible Relevance to Metalated DNA Triplex Structures

et al. 1999

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“…The structure in Figure 9 shows a mononuclear adduct where the Pt atom is bound to two molecules of 9-EtG through N7 in a square planar geometry similarly to other examples of refs (12−14). Both 9-EtG molecules are coplanar, whereas isopropylamine ligands are 180° twisted giving the most stable conformation to the molecule.…”

Section: Resultsmentioning

confidence: 62%

New Findings in the Signaling Pathways of cis and trans Platinum Iodido Complexes’ Interaction with DNA of Cancer Cells

et al. 2019

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We have selected a series of aliphatic amine platinum compounds bearing chloride and/or iodide as the leaving groups. The complexes’ cytotoxicity and interaction with DNA indicated differences in the reactivity. Now, we are reporting on the analysis of their molecular mechanism of action on gastric cancer cells. Our data reveals differences between them. Chlorido drugs showed similar behavior to cisplatin; they both required p53 to induce apoptosis but only cis-ipa showed DNA damage requirement for apoptosis induction. On the contrary, cis and trans iodido induced cell death independent of p53 activity, and they induced cell death through Bid activation, so their toxicity could be enhanced in a combined treatment with novel Bcl-2 protein family inhibitors. We also report the structural features of the DNA adduct for one of the complexes by X-ray diffraction. These findings represent a step forward in the search for new platinum-derived agents more specific and effective in the treatment of cancer.

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“…The following compounds were prepared as previously: cis-[(NH 3 ) 2 Pt(9-EtG) 2 ] 2 , [63] trans-[(NH 3 ) 2 Pt(9-EtG) 2 ] 2 , [64] trans-[(CH 3 NH 2 ) 2 Pt(9-EtG) 2 ] 2 , [65] and trans-[(CH 3 NH 2 ) 2 Pt(1-MeC)(9-EtG)]…”

Section: Methodsmentioning

confidence: 99%

Effects of (N7)-Coordinated Nickel(II), Copper(II), or Platinum(II) on the Acid-Base Properties of Guanine Derivatives and Other Related Purines[≠]

Song

Zhao

Griesser

et al. 1999

Chemistry - A European Journal

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This study is dedicated to Professor Dr. R. Bruce Martin, University of Virginia, Charlottesville (USA), on the occasion of his 70th birthday, with the very best wishes of the authors for all his future endeavors and with deep appreciation for friendship and unselfish advice provided over many years to H.S. and B.L.Abstract: The effect of Ni 2 , Cu 2 , and cis-a 2 Pt 2 or trans-a 2 Pt 2 (where a NH 3 or CH 3 NH 2 ), if coordinated to the N7 site of guanine residues, on the acid ± base properties of complexes containing guanine derivatives as ligands is considered. The various acidity constants were determined by potentiometric pH titrations. Over 60 acidity constants are listed; about half of these are new. In many instances micro acidity constants have been derived that allow a quantification of the intrinsic acid ± base properties of a certain site, which are otherwise blurred by the pK a values of overlapping buffer regions. This material allows many comparisons; among these is the observation that the acidifying properties of (N7)-coordinated divalent metal ions on the corresponding (N1)H sites in a guanine derivative decrease in the following series:The data also indicate that the effects are similar for guanine and hypoxanthine residues, but that they are more pronounced for adenine derivatives because in the latter case a (N7)-bound M 2 affects a (N1)H site; hence, a further charge effect is operative here. The available material does not yet allow certain prediction of the more subtle differences occurring between the cis and trans isomers of Pt 2 complexes, but replacement of, for example, NH 3 in the coordination sphere of Pt 2 with CH 3 NH 2 has an effect. Of course, as one might expect, the effect of (N7)-bound Pt 2 in guanine nucleotide complexes is smaller on the more remote phosphate groups than it is on the closer (N1)H sites. By evaluation (by means of micro acidity constants) of data available for hypoxanthine derivatives it is also shown that (N1) À -bound Pt 2 has an acidifying effect on the (N7)H site comparable to that of (N7)-coordinated Pt 2 on the (N1)H site.

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Mono- and bis(9-ethylguanine) complexes of trans-(CH3NH2)2PtII. X-ray structure of the 2:1 complex and redistribution of the 1:1 compound

Cited by 18 publications

References 38 publications

New Findings in the Signaling Pathways of cis and trans Platinum Iodido Complexes’ Interaction with DNA of Cancer Cells

Effects of (N7)-Coordinated Nickel(II), Copper(II), or Platinum(II) on the Acid-Base Properties of Guanine Derivatives and Other Related Purines[≠]

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Mono- and bis(9-ethylguanine) complexes of trans-(CH3NH2)2PtII. X-ray structure of the 2:1 complex and redistribution of the 1:1 compound

Cited by 18 publications

References 38 publications

Metal-Modified Base Pairs Involving Different Donor Sites of Purine Nucleobases: trans-[a2Pt(7,9-DimeG-N1)(9-EtGH-N7)]2+andtrans-[a2Pt(7,9-DimeG-N1)(9-EtG-N7)]+(a = NH3or CH3NH2; 9-EtGH = 9-Ethylguanine; 7,9-DimeG = 7,9-Dimethylguanine). Possible Relevance to Metalated DNA Triplex Structures

Metal-Modified Base Pairs Involving Different Donor Sites of Purine Nucleobases: trans-[a2Pt(7,9-DimeG-N1)(9-EtGH-N7)]2+andtrans-[a2Pt(7,9-DimeG-N1)(9-EtG-N7)]+(a = NH3or CH3NH2; 9-EtGH = 9-Ethylguanine; 7,9-DimeG = 7,9-Dimethylguanine). Possible Relevance to Metalated DNA Triplex Structures

New Findings in the Signaling Pathways of cis and trans Platinum Iodido Complexes’ Interaction with DNA of Cancer Cells

Effects of (N7)-Coordinated Nickel(II), Copper(II), or Platinum(II) on the Acid-Base Properties of Guanine Derivatives and Other Related Purines[≠]

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