Carbohydrates Coordinated to Platinum(<scp>IV</scp>) through Hydroxyl Groups: A New Class of Platinum Complexes with Bioactive Ligands

Steinborn, Dirk; Junicke, Henrik; Bruhn, Clemens

doi:10.1002/anie.199726861

Cited by 25 publications

(2 citation statements)

References 33 publications

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“…Search for the Most Favorable Binding Site for Complexation of Tetrachloroplatinate Anion (PtCl 4 2- ). Binding of Pt(II) to both tertiary amine N (N3) and secondary amide N (N2) in PAMAM dendrimers 11 and to secondary amide O (O) and to hydroxyl O (OH) in other compounds has been suggested by experimental work. Therefore several structures (for selected geometric parameters, see Table A, Supporting Information) of the form fragment−PtCl 3 - where a Cl - ligand has been replaced by a dendrimer atom site (N3, N2, O, and OH) were calculated.…”

Section: Resultsmentioning

confidence: 99%

Pt(II) Uptake by Dendrimer Outer Pockets: 1. Solventless Ligand Exchange Reaction

Tarazona-Vasquez

Balbuena

2008

J. Phys. Chem. B

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Density functional theory is used to elucidate molecular-level details of the complexation of Pt(II) metal compounds with PAMAM dendrimers. Particular attention is given to the ligand exchange reaction (LER). Binding of Pt(II) complexes to one dendrimer atom site (monodentate binding) is found to be thermodynamically feasible. Tertiary amine nitrogen (N3) is found to be the most favorable binding site in agreement with previous experimental work. Comparing the binding of Pt(II) species to atom sites in simple molecules with those to similar sites in dendrimer outer pockets allowed us to assess the impact of dendrimer branches on the binding. The impact of branches is manifested in more complex reaction profiles for complexation of Pt(II) species, because of the numerous ways in which a single molecule could be hosted by an outer dendrimer pocket. It is found that branches slightly improve the binding strength to all sites, particularly to N3. However, they could also be responsible for the increase of the activation energy for direct LER of PtCl(4)(2-) and PtCl(3)(H(2)O)- at the N3 site. Considering the thermodynamics of both complexation steps, namely noncovalent binding (NCB) and LER, it is found that to have a PtCl(3)(-) moiety bound to N3, as a result of NCB + LER operating on PtCl(4)(2-), is more likely than to have any other ion hosted in the outer pockets. However, the activation energy for direct LER of PtCl(4)(2-) at the N3 site is found to be the largest among all Pt(II) metal complexes and even larger than the barrier to its own aquation yielding PtCl(3)(H(2)O)(-).

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Section: Resultsmentioning

confidence: 99%

Pt(II) Uptake by Dendrimer Outer Pockets: 1. Solventless Ligand Exchange Reaction

Tarazona-Vasquez

Balbuena

2008

J. Phys. Chem. B

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“…22 On the other hand, the usage of carbohydrate moieties for the construction of biologically active the platinum(II) and palladium(II) complexes is now of increasing interest within bioinorganic chemistry. [23][24][25][26] It was shown a long ago that many organic compounds combining both types of structural features (i.e. 1,2-diaminosaccharides) formed Pt(II) and Pd(II) complexes with noticeable anti-tumor properties.…”

Section: Introductionmentioning

confidence: 99%

Structure and dynamics of methyl cis-3,4-diamino-2,3,4,6-tetradeoxy-α-l-lyxo-hexopyranoside complexes with PtCl2 and PdCl2, by 1H, 2H, 13C, 15N and 195Pt NMR spectroscopy in DMSO, CD3CN and H2O

et al. 2008

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Pd(II) and Pt(II) chloride complexes with LL = methyl cis-3,4-diamino-2,3,4,6-tetradeoxy-alpha-l-lyxo-hexopyranoside of the formulae [Pd(LL)Cl(2)] and [Pt(LL)Cl(2)], 1, were studied by (1)H, (2)H, (13)C, (15)N and (195)Pt NMR spectroscopy. These techniques were applied for characterization of the structure and ligand exchange dynamics, in case of diastereomeric species formed from 1 in DMSO-d(6), DMSO-h(6) and H(2)O; their general formula was [Pt(LL)XY](+) (X = Cl, Y = DMSO-d(6), 2a; X = DMSO-d(6), Y = Cl, 2b; X = Cl, Y = DMSO-h(6), 2a'; X = DMSO-h(6), Y = Cl, 2b'; X = Cl, Y = H(2)O, 3a; X = H(2)O, Y = Cl, 3b). Their theoretical structures and NMR parameters, calculated at the level of DFT approach, were also presented and compared to the experimental data. The model complex [Pt(trans-diaminocyclohexane)Cl(2)], 4, was studied as well. To the best of our knowledge, this work is the first account dealing with the detailed analysis of structure and dynamics of ligand exchange processes in organic solvents and water, performed for a PtCl(2) complex containing a diaminosugar moiety. The kinetic behavior of the studied coordination compounds suggests that some of them may be potentially active in bioassays against cancer cells. Compound 1 exhibits noticeable versatile ligand exchange possibilities in DMSO and H(2)O. Particularly, it undergoes solvolysis in DMSO-d(6), exchanging one chloride atom and yielding two diastereomers 2a and 2b; the former, being the kinetically favored species, has the DMSO-d(6) ligand syn to the N(3) atom. The lyophilisate of the respective 2a + 2b mixture, earlier equilibrated in DMSO-d(6), after dissolving in H(2)O yields only the latter isomer, which is thermodynamically favored. The solvolysis of 1 in H(2)O yields instantaneously two diastereomeric monoaquated species, 3a and 3b, amounting to 10% of each.

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Organometallic Supramolecular Chemistry with Monosaccharides: Triethylammoniumμ-Chloro-bis{chloro(η5-cyclopentadienyl)(methyl 4,6-O-benzylidene-β-D-glucopyranosidato-1κO2,1:2κO3)zirconate}

Jessen¹,

Haupt²,

Heck³

2001

Chem. Eur. J.

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The reaction of [CpZrCl 3 (thf) 2 ] with methyl 4,6-Obenzylidene-b-d-glucopyranoside (bMeBGH 2 , 1) in the presence of Et 3 N results in the formation of the zirconate complex [Et 3 NH][(CpZrCl) 2(2). X-ray structure analyses were performed from the ligand precursor b-MeBGH 2 1 as well as from 2. Compound 1 crystallizes in the monoclinic chiral space group P2 1 . The molecules show a flat arrangement including the benzylidene protecting group, and are packed in columns. The columns are held together in pairs by the formation of hydrogen bonds between the hydroxy functions in positions 2 and 3. Compound 2 crystallizes in the orthorhombic space group P2 1 2 1 2 1 . The b-MeBG ligands are chelating the Zr atoms through the oxygen atoms in positions 2 and 3 of the glucopyranosidato ligand revealing a 1-zircona-2,5-dioxolane moiety each; the oxygen atom in position 3 is linked to both of the Zr atoms. Additionally one chloro ligand is bridging the two Zr centers. Two terminally bound chloro ligands stick out from the two Zr atoms into a chiral U-shaped cavity constructed by the two b-MeBG ligands. The cavity incorporates the tertiary ammonium cation [Et 3 NH] , which is bound to one of the terminal chloro ligands through a hydrogen bond. The inclusion of the [Et 3 NH] cation in the U-shaped cavity, even in solution, is demonstrated by NMR spectroscopic data.

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Carbohydrates Coordinated to Platinum(IV) through Hydroxyl Groups: A New Class of Platinum Complexes with Bioactive Ligands

Cited by 25 publications

References 33 publications

Pt(II) Uptake by Dendrimer Outer Pockets: 1. Solventless Ligand Exchange Reaction

Pt(II) Uptake by Dendrimer Outer Pockets: 1. Solventless Ligand Exchange Reaction

Structure and dynamics of methyl cis-3,4-diamino-2,3,4,6-tetradeoxy-α-l-lyxo-hexopyranoside complexes with PtCl2 and PdCl2, by 1H, 2H, 13C, 15N and 195Pt NMR spectroscopy in DMSO, CD3CN and H2O

Organometallic Supramolecular Chemistry with Monosaccharides: Triethylammoniumμ-Chloro-bis{chloro(η5-cyclopentadienyl)(methyl 4,6-O-benzylidene-β-D-glucopyranosidato-1κO2,1:2κO3)zirconate}

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