Explorations of the nature of the coupling interactions between vitamin C and methylglyoxal: a DFT study

Abstract

As the first step toward understanding the augment role of vitamin C (Vc) for the anticancer effect of methylglyoxal (MG), the nature of the coupling interactions between Vc and MG has been systematically investigated at the B3LYP/6-311??G** level of theory in combination with the atoms in molecules (AIM) theory, natural bond orbital (NBO) method, and energy decomposition analysis (EDA). The possible stable complexes have been located on their potential energy surface (PES). Most of them are characterized by one or two intermolecular H-bonds with the binding energies varying from -11.1 to -2.0 kcal/mol. AIM analyses suggest that all the intermolecular H-bonds have been predominated by the electrostatic interaction. A good linear correlation between the intermolecular H-bond distance and the electron density as well as its Laplacian at the bond critical point of the intermolecular H-bond has been observed. Depending on the selected coupling modes between Vc and MG, the origin of the blue-shifts of the stretching vibrational frequencies of different C-H bonds has been elucidated. Additionally, the inherent reason for the positive role of Vc in the anticancer process for MG has been verified through the investigation of the one-electron oxidation behaviors of the most stable complex.

Methane activation on Fe4 cluster: A density functional theory study

“…AIM theory and NBO analysis which have been used to successfully determine intermolecular interactions of different systems were carried out on the basis of the optimized structures of Fe 4 -CH 4 system in order to better clarify the nature of the intermolecular interactions [18,[20][21][22][23][24][25][26][27]. In the AIM analyses, the existence of a bond is indicated by the presence of a so-called bond critical point (BCP).…”

Tailoring Intermolecular Interactions Towards High‐Performance Thermoelectric Ionogels at Low Humidity

“…In contrast, ∇ 2 ρ bcp > 0 and H bcp < 0 for O–H⋅⋅⋅O confirm that the OAC − anions are tightly bound to PEO through the terminal hydroxyl groups. [ 21,22 ] Based on these results, we can conclude that the increase of S i for PEO‐Emim:OAC ionogels is attributed to the enlarged migration difference between Emim + cations and OAC − anions. As illustrated in Figure 1e, the dual effects of ether oxygen group with Emim + and hydroxyl group with OAC – account for the dissociation of IL and restrict the movement of OAC − through stronger binding.…”