Guanine complexes with 3d metal perchlorates

Mikulski, Chester M.; Kurlan, Matthew K.; Bayne, Monica; Gaul, Michele; Karayannis, Nicholas M.

doi:10.1016/s0020-1693(00)85780-1

Cited by 26 publications

(2 citation statements)

References 43 publications

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“…There are several possible binding sites in guanine, that is, N1, N3, N7, and N9. 41 The νC 6 dO frequency (1722 cm -1 ) of guanine is lowered to an appreciable extent upon the metal complex formation. The infrared spectral studies of the metal complexes exhibit the lowering in the frequency of the νC 5 sN 7 sC 8 band (1255 cm -1 ) in comparison with the νC 2 sN 3 sH and νN 9 sH bands.…”

Section: Resultsmentioning

confidence: 99%

“…The bands corresponding to νN−H (3135 cm -1 ) and νCNH 2 + νCN (1280 cm -1 ) of 5FC show considerable shifts in complexes, suggesting the participation of N3 in coordination with metal ions, which is supported by the shifting of the νC2O (1650 cm -1 ) band of 5FC to the higher frequency side due to nontransfer of electrons from the N3 position to the C2O group. There are several possible binding sites in guanine, that is, N1, N3, N7, and N9 . The νC 6 O frequency (1722 cm -1 ) of guanine is lowered to an appreciable extent upon the metal complex formation.…”

Section: Resultsmentioning

confidence: 99%

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Nucleic Acid Base Pair and Mispair Interactions with Metal IonsA Thermodynamic Aspect

Tyagi

Gencaslan

2003

J. Chem. Eng. Data

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Potentiometric equilibrium measurements were made for some metal ions (M(II) = Co(II), Ni(II), Cu(II), Zn(II), Cd(II), Ca(II), Sr(II), and Ba(II)) with guanine (A) in a 1:1 (M(II):A) ratio and with cytosine, cytidine, 5-bromocytosine, 5-azacytosine, and 5-fluorocytosine as primary ligands (L) and guanine as secondary ligand in a 1:1:1 (M(II):L:A) ratio at (25.0, 35.0, and 45.0) °C and I = 0.1 mol·dm-3 NaNO3 in aqueous solution. The experimental pH-titration data were analyzed by using a BEST computer program in order to evaluate the formation constants of various intermediate species and their relative distribution. The experimental conditions were selected in such a way that the self-association of the nucleobases and their complexes due to stacking interaction was negligibly small, so that only the neutral monomeric and hydroxo ternary complexes were studied. The enthalpy (Δf H°) and entropy (Δf S°) changes for the formation of binary and ternary complexes were calculated from temperature coefficient data. The δΔf S° values are positive for all the metal ligand systems. The negative δΔf H° values indicate the extra stabilization of most of the ternary complexes by the exothermic enthalpy change (δΔf S° = ΔT S° − ΔB S° and δΔf H° = ΔT H° − ΔB S° where ΔT S°, ΔT H° and ΔB S°, ΔB H° are the entropy and enthalpy values associated with the ternary and binary complexes, respectively). On the basis of IR data for metal complexes with the 5FC−G mispair, it has been proposed that the guanine is bonded to metal ions through N1/C6O and N7, whereas cytosine and its derivatives are bonded through N3 atoms in ternary complexes.

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Section: Resultsmentioning

confidence: 99%

Section: Resultsmentioning

confidence: 99%

Nucleic Acid Base Pair and Mispair Interactions with Metal IonsA Thermodynamic Aspect

Tyagi

Gencaslan

2003

J. Chem. Eng. Data

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Dicarbonylrhodium(I)‐Komplexe mit Nucleobasen und Nucleosiden

1983

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Durch Umsetzung von [Rh(CO),Cl], mit verschiedenen Nucleobasen und Nucleosiden wurden die Komplexe (OC),Rh(L)CI (1) (L = 9-Methylguanin, Hypoxanthin, Cytosin, 1-Methylcytosin, Guanosin, 1-Methylguanosin, Inosin, Adenosin, 7-Desazaadenosin, Cytidin) und (OC),CIRh-(Guanin)RhC1(C0)2 (2) erhalten. Die Koordination der Nucleobasen an das Rhodiumatom wird an Hand der 'H-NMR-Spektren diskutiert. Dicarbonyl Rhodium(1) Complexes with Nurleobases and Nucleosides')The reaction of [Rh(CO),Cl], with various nucleobases and nucleosides gives the complexes (OC),Rh(L)CI (1) (L = 9-methylguanine, hypoxanthine, cytosine, 1-methylcytosine, guanosine, 1-methylguanosine, inosine, adenosine, cytidine, 7-deazaadenosine) and (OC),CIRh(guanine)-RhCI(CO), (2). The coordination of the nucleobases to the rhodium atom is discussed on the basis of the 'H NMR spectra.Seit der Entdeckung der Antiturnoraktivitat von cis-Platin(II)-Komplexen2) werden Komplexe von Ubergangsmetallen mit Nucleobasen eingehend untersucht 3). In Fortfuhrung unserer Arbeiten uber das komplexchemische Verhalten von Nucleobasen4) wird im folgenden uber die Reaktion des dimeren Dicarbonylrhodiumchlorids [Rh(CO),CI], mit verschiedenen Nucleobasen und Nucleosiden berichtet. Es ist lange bekannt, da8 sich [Rh(CO),CI], mit neutralen Liganden unter Spaltung der Chlorobrucken zu monomeren, planaren Komplexen Rh(CO),LCl urnsetzt 5 ) . Es ist auch zu erwarten, da8 die ambivalenten Nucleobasen als Briicken zwischen zwei Rhodiumatomen auftreten konnen. So wurden z. B. Rhodium(1)-Kornplexe rnit Imidazolat-Brucken erhalten6). In der letzten Zeit wurden rnit dem antitumoraktiven [Rh"-A~etat,],~) Komplexe mit Nucleobasen beschrieben*). Verschiedene Rhodium( I)und Rhodium(I11)-Komplexe zeigen Antitumor-Aktivitat 9).

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