Roles of intramolecular and intermolecular hydrogen bonding in a three-water-assisted mechanism of succinimide formation from aspartic acid residues.

Computational study of the intramolecular proton transfer between 6-hydroxypicolinic acid tautomeric forms and intermolecular hydrogen bonding in their dimers

This paper is a density functional theory (DFT) calculation of intramolecular proton transfer (IPT) in 6-hydroxypicolinic acid (6HPA, 6-hydroxypyridine-2-carboxylic acid) tautomeric forms. The transition state for the enol-to-keto transition is reported in the gas phase and in four different solvents. The planar and non-planar dimer forms of 6HPA keto and enol, respectively, were also studied i...

Inductive Effect of Bioactive Intermolecular Hydrogen Bonding Complex of 1,2,4,5 –Tetrazine and Inorganic Acid by NMR and QTAIM

In this paper, NMR and QTAIM analysis for three substituted of T2SA complex was investigated in the gas and four solvents at DFT level. Intermolecular O–H…N hydrogen bonds between 1,2,4,5-Tetrazine and Sulphurous acids enhance the stability of complex.1,2,4,5-Tetrazine is a highly reactive diene for [4+2] inverse-Diels–Alder cycloaddition processes and an excellent precursor to attain the pyrid...

Computational study of three dimensional potential energy surfaces in intermolecular hydrogen bonding of cis-urocanic acid

Acetic Acid Can Catalyze Succinimide Formation from Aspartic Acid Residues by a Concerted Bond Reorganization Mechanism: A Computational Study

Succinimide formation from aspartic acid (Asp) residues is a concern in the formulation of protein drugs. Based on density functional theory calculations using Ace-Asp-Nme (Ace = acetyl, Nme = NHMe) as a model compound, we propose the possibility that acetic acid (AA), which is often used in protein drug formulation for mildly acidic buffer solutions, catalyzes the succinimide formation from As...

Ab Initio Quantum Chemical Studies of 15N and 13C NMR Shielding Tensors in Serine and Complexes of Serine- nH2O: Investigation on Strength of the CαH…O Hydrogen bonding in the Amino Acid Residue.

In this paper, the hydrogen bonding (HB) effects on the NMR chemical shifts of selected atoms in serineand serine-nH2O complexes (from one to ten water molecules) have been investigated with quantummechanical calculations of the 15N and 13C tensors. Interaction with water molecules causes importantchanges in geometry and electronic structure of serine.For the compound studied, the most importan...