Hydrogen bonding in complexes of adenosine and 4-thiouridine: a low-temperature NMR study

Janke, Eline M. Basílio; Dunger, Anita; Limbach, Hans−Heinrich; Weisz, Klaus

doi:10.1002/mrc.945

Cited by 26 publications

(3 citation statements)

References 21 publications

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“…As expected, the effect of the substitution of sulfur for oxygen in position 6 for G and position 4 for T and U on the conformation of single-strand molecules is small. Larger changes occur for double-strand DNA because of the significant weakening for the base pairing . This change makes the S donor or the N−S chelator more accessible to an eventual metal center coming from the major grove.…”

Section: Discussionmentioning

confidence: 99%

Study of Ruthenium(II) Complexes with Anticancer Drugs as Ligands. Design of Metal-Based Phototherapeutic Agents

et al. 2003

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The reaction of trans-[RuCl(2)(PPh(3))(3)] (Ph = C(6)H(5)) with 2-thio-1,3-pyrimidine (HTPYM) and 6-thiopurines (TPs) produced mainly crystalline solids that consist of cis,cis,trans-[Ru(PPh(3))(2)(N,S-TPYM)(2)] (1) and cis,cis,trans-[Ru(PPh(3))(2)(N(7),S-TPs)(2)]X(2) (X = Cl(-), CF(3)SO(3)(-)). In the case of TPs, other coordination isomers have never been isolated and reported. Instead, the mother liquor obtained after filtration of 1 produced red single crystals of trans,cis,cis-[Ru(PPh(3))(2)(N,S-TPYM)(2)].2H(3)O(+).2Cl(-) (2.2H(3)O(+).2Cl(-)). Selected ruthenium(II)-thiobase complexes were studied for their structural, reactivity, spectroscopic, redox, and cytotoxic properties. Single crystals of 1 contain thiopyrimidinato anions chelated to the metal center via N and S. The Ru[bond]N bonds are significantly elongated for 1 [2.122(2) and 2.167(2) A] with respect to 2 [2.063(3) A] because of the trans influence from PPh(3). The coordination pseudo-octahedron for 2 is significantly elongated at the apical sites (PPh(3) ligands). Solutions of cis,cis,trans isomers in air are stable for weeks, whereas those of 2 turn green within 24 h, in agreement with the respective redox potentials. cis,cis,trans- and trans,cis,cis-[Ru(PH(3))(2)(N,S-TPYM)(2)], as optimized through the DFT methods at the Becke3LYP level are in good agreement with experimental geometrical parameters (1 and 2), with cis,cis,trans being more stable than trans,cis,cis by 3.88 kcal. The trend is confirmed by molecular modeling based on semiempirical (ZINDO/1) and molecular mechanics (MM) methods. Cytotoxic activity measurements for cis,cis,trans-[Ru(PPh(3))(N-THZ)(N(7),S -H(2)TP)(2)]Cl(2) (4) (THZ = thiazole, H(2)TP = 6-thiopurine) and cis,cis,trans-[Ru(PPh(3))(2)(N(7),S-HTPR)2]Cl(2) (5) (HTPR = 6-thiopurine riboside) against ovarian cancer cells A2780/S gave IC(50) values of 17 +/- 1 and 29 +/- 9 microM, respectively. Furthermore, the spectral analysis of HTPYM, TPs, and their Ru(II) complexes in solution shows that intense absorptions occur in the UVA/vis region of light, whereas standard nucleobases absorb in the UVB region.

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Section: Discussionmentioning

confidence: 99%

Study of Ruthenium(II) Complexes with Anticancer Drugs as Ligands. Design of Metal-Based Phototherapeutic Agents

et al. 2003

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“…Many theoretical and experimental investigations have been concerned with the stability of the N-HÁ Á ÁO and the N-HÁ Á ÁS hydrogen bonds, but no clear trend has emerged. Ab initio energy calculations (Š poner et al, 1997;Basilio Janke et al, 2001) and a study of the thermodynamics of RNA duplexes containing thiouridine (Testa et al, 1999) showed that a base pair connected by an N-HÁ Á ÁO hydrogen bond is more stable than that connected by an N-HÁ Á ÁS hydrogen bond. In the case of 2-thiouridine, the Watson-Crick base pair with adenine, which is connected by an N-HÁ Á ÁO hydrogen bond, is preferred over the wobble base pair with guanine, which is linked by an N-HÁ Á ÁS hydrogen bond.…”

Section: Commentmentioning

confidence: 99%

Cocrystals of 6-propyl-2-thiouracil: N—H...OversusN—H...S hydrogen bonds

Tutughamiarso

Egert

2011

Acta Crystallogr C

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In order to investigate the relative stability of N—H...O and N—H...S hydrogen bonds, we cocrystallized the antithyroid drug 6‐propyl‐2‐thiouracil with two complementary heterocycles. In the cocrystal pyrimidin‐2‐amine–6‐propyl‐2‐thiouracil (1/2), C4H5N3·2C7H10N2OS, (I), the `base pair' is connected by one N—H...S and one N—H...N hydrogen bond. Homodimers of 6‐propyl‐2‐thiouracil linked by two N—H...S hydrogen bonds are observed in the cocrystal N‐(6‐acetamidopyridin‐2‐yl)acetamide–6‐propyl‐2‐thiouracil (1/2), C9H11N3O2·2C7H10N2OS, (II). The crystal structure of 6‐propyl‐2‐thiouracil itself, C7H10N2OS, (III), is stabilized by pairwise N—H...O and N—H...S hydrogen bonds. In all three structures, N—H...S hydrogen bonds occur only within R22(8) patterns, whereas N—H...O hydrogen bonds tend to connect the homo‐ and heterodimers into extended networks. In agreement with related structures, the hydrogen‐bonding capability of C=O and C=S groups seems to be comparable.

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“…Understanding the H-bonding abilities of modified nucleobases is a key step in uncovering the biomolecular mechanisms of mutagenesis and damaged DNA recognition. Gas-phase MS, thermal denaturation of double-stranded NAs, microcalorimetry, and nuclear magnetic resonance (NMR) spectroscopy − have been employed in studies of H-bonding interactions between nucleobases. NMR spectroscopy is considered the most powerful tool for providing information not only on complexation energies but also on the geometries of H-bonded complexes. ,, In addition to experimental studies, bonding interactions between nucleobases have been extensively studied using computational methods. − …”

Section: Introductionmentioning

confidence: 99%

Hydrogen-Bonding Interactions of 8-Substituted Purine Derivatives

2023

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Hydrogen bonding between nucleobases is a crucial noncovalent interaction for life on Earth. Canonical nucleobases form base pairs according to two main geometries: Watson–Crick pairing, which enables the static functions of nucleic acids, such as the storing of genetic information; and Hoogsteen pairing, which facilitates the dynamic functions of these biomacromolecules. This precisely tuned system can be affected by oxidation or substitution of nucleobases, leading to changes in their hydrogen-bonding patterns. This paper presents an investigation into the intermolecular interactions of various 8-substituted purine derivatives with their hydrogen-bonding partners. The systems were analyzed using nuclear magnetic resonance spectroscopy and density functional theory calculations. Our results demonstrate that the stability of hydrogen-bonded complexes, or base pairs, depends primarily on the number of intermolecular H-bonds and their donor–acceptor alternation. No strong preferences for a particular geometry, either Watson–Crick or Hoogsteen, were found.

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Hydrogen bonding in complexes of adenosine and 4-thiouridine: a low-temperature NMR study

Cited by 26 publications

References 21 publications

Study of Ruthenium(II) Complexes with Anticancer Drugs as Ligands. Design of Metal-Based Phototherapeutic Agents

Study of Ruthenium(II) Complexes with Anticancer Drugs as Ligands. Design of Metal-Based Phototherapeutic Agents

Cocrystals of 6-propyl-2-thiouracil: N—H...OversusN—H...S hydrogen bonds

Hydrogen-Bonding Interactions of 8-Substituted Purine Derivatives

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