A quantum chemical study on selected π-type hydrogen-bonded systems

Tang, Tao; Hu, Wenjun; Yan, Dayu; Cui, Yun-Ping

doi:10.1016/0166-1280(90)85033-j

Cited by 63 publications

(41 citation statements)

References 19 publications

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“…[94][95] , a positive ∇ ଶ ሺ‫ݎ‬ ሻ, meaning that the interaction is mainly electrostatic, and a low ε, indicating that H-bonds are stable. We observed C β -H···O i+3 → i BCPs, also occurring in natural peptides, 55,57 with ρ(r c ) between 0.003-0.009 a.u., which is about one half of the electron density of a typical N-H···O BCP (Tables S6-23, S.I.).…”

Section: As Shown By Results Of Dssp and H-bond Analyses Reported Inmentioning

confidence: 98%

Mechanism of Stabilization of Helix Secondary Structure by Constrained Cα-Tetrasubstituted α-Amino Acids

et al. 2015

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The theoretical basis behind the ability of constrained Cα-tetrasubstituted amino acids (CTAAs) to induce stable helical conformations has been studied through Replica Exchange Molecular Dynamics Potential of Mean Force Quantum Theory of Atoms In Molecules calculations on Ac-l-Ala-CTAA-l-Ala-Aib-l-Ala-NHMe peptide models. We found that the origin of helix stabilization by CTAAs can be ascribed to at least two complementary mechanisms limiting the backbone conformational freedom: steric hindrance predominantly in the (+x,+y,-z) sector of a right-handed 3D Cartesian space, where the z axis coincides with the helical axis and the Cα of the CTAA lies on the +y axis (0,+y,0), and the establishment of additional and relatively strong C-H···O interactions involving the CTAA.

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Section: As Shown By Results Of Dssp and H-bond Analyses Reported Inmentioning

confidence: 98%

Mechanism of Stabilization of Helix Secondary Structure by Constrained Cα-Tetrasubstituted α-Amino Acids

et al. 2015

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“…The values of the electron density at all HBCPs, F(r c ), all fall in the range 0.002-0.022, which is within the range of common hydrogen bonds. 37,58 The Laplacian, ∇ 2 F(r c ), is positive for all bonds, which is expected for hydrogen bonds. Also, no bonds exhibit a notable ellipticity.…”

Section: Common Characteristics Of the Model Peptidesmentioning

confidence: 98%

QTAIM Study of an α-Helix Hydrogen Bond Network

et al. 2009

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The structures of 19 alpha-helical alanine-based peptides, 13 amino acids in length, have been fully optimized using density functional theory and analyzed by means of the quantum theory of atoms in molecules. Two types of N-H...O bonds and one type of C-H...O bond have been identified. The value of the electron density at hydrogen bond critical points corresponding to N-H...O interactions is higher than that of C-H...O interactions. The effect of amino acid substitution at the central position of the peptide on the hydrogen bond network of the alpha-helix has been assessed. The strength of the hydrogen bond network, measured as the summation of the electron density over the hydrogen bond critical points, may be used to explain experimental relative helix propensities of amino acids in cases where solvation and entropic effects cannot.

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“…For example, in adduct 1 ‐OAc N–Hs are elongated by H B ~0.023 and H C ~0.021 Ǻ. In addition, aromatic H A ···O and H D ···O (~2.5‐ 2.8 Å) H‐bond interactions are also observed .…”

Section: Resultsmentioning

confidence: 99%

Preferred Binding of Carboxylates by Chiral Urea Derivatives Containingα-Phenylethyl Group

et al. 2016

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An efficient, simple protocol for the synthesis of a new family of chiral ureas 1 -4 is described. The binding properties of 1 -4 toward different anion (acetate, benzoate, fluoride, and chloride) have been studied by 1 H-NMR titration and have been observed in the case of 4 is a selective receptor for acetate. The theoretical calculation M06/6-311+G(d,p) helped us explain the binding properties observed. The most interesting observation is that this calculated structure is consistent with expected, based on the concept of allylic 1,3-strain (A 1,3 strain). When chiral caboxylates were studied, urea 1 was the best in discriminating between enantiomers.

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A quantum chemical study on selected π-type hydrogen-bonded systems

Cited by 63 publications

References 19 publications

Mechanism of Stabilization of Helix Secondary Structure by Constrained Cα-Tetrasubstituted α-Amino Acids

Mechanism of Stabilization of Helix Secondary Structure by Constrained Cα-Tetrasubstituted α-Amino Acids

QTAIM Study of an α-Helix Hydrogen Bond Network

Preferred Binding of Carboxylates by Chiral Urea Derivatives Containingα-Phenylethyl Group

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