Interactions between temozolomide and quercetin

Abstract

Temozolomide and quercetin are both molecules with important pharmaceutical activity, whose effects can mutually enhance one another when clinically applied simultaneously. Quantum chemical calculations are used to examine how the two molecules might interact with one another. The most stabilizing force arises when the aromatic systems of the two molecules are arranged parallel to one another. These stacked configurations are reinforced by H-bonds, but geometries containing only H-bonds, without the aromatic stacking, are much less stable, even if the H-bonds are short and strong. Comparison between B3LYP and B3LYP-D binding energies allows an evaluation of dispersion energy, which is found to be a primary contributor to the stability of the stacked structures.

Interactions between temozolomide and guanine and its S and Se-substituted analogues

“…Negative red sections are located around unprotonated N atoms, as well as the O/S/Se atoms. The corresponding MEP around TMZ was previously reported . This MEP in Figure exhibits primary negative potential around its two O atoms, with positive regions around its H atoms and directly above its six‐membered ring.…”

“…[82,83] For that reason, the molecular electrostatic potentials (MEPs) of the molecules of interest are presented in Figure 4, reported. [29][30][31][32][33][34][35] This MEP in Figure 4 exhibits primary negative potential around its two O atoms, with positive regions around its H atoms and directly above its six-membered ring.…”

“…As a means to focus on certain fundamentals, interactions of TMZ with small molecules have been examined previously by this laboratory, specifically H 2 O, HCl, BH 3 , and . Using the lessons learned, work progressed to larger pharmacological agents chloroquine and quercetin, as well as possible homodimers of TMZ . Progressing toward other aspects of biological activity, the interaction of TMZ with each of the nucleic acid bases was examined and demonstrated the possibility of binding much like the standard Watson‐Crick pairing that is instrumental to the structure and function of DNA .…”

“…[29][30][31] Using the lessons learned, work progressed to larger pharmacological agents chloroquine and quercetin, as well as possible homodimers of TMZ. [32][33][34] Progressing toward other aspects of biological activity, the interaction of TMZ with each of the nucleic acid bases was examined and demonstrated the possibility of binding much like the standard Watson-Crick pairing that is instrumental to the structure and function of DNA. [35] But at the same time, quite different sorts of geometries, energetically similar to or even more stable than such pairing were revealed for the first time.…”

Chitosan–Quercetin Bioconjugate as Multi‐Functional Component of Antioxidants and Dual‐Responsive Hydrogel Networks

“…[67][68][69] Caffeine was loaded in the hydrogels by soaking procedure with a loading efficiency >85% for both hydrogels and a loading percent, DL(%), of 8.0 and 8.5 for HB and HQ, respectively. The slight difference in the DL values can be related to the ability of Q moieties to interact with drug molecules via aromatic interactions, [70,71] resulting in higher affinity of caffeine toward HQ.…”