Theoretical Insights into the Oxidative Stress-Relieving Properties of Pinocembrin─An Isolated Flavonoid from Honey and Propolis

Abstract

Bee products are a valuable group of substances that have a wide range of applications for humans. They contain a high level of polyphenolic compounds, which have been shown to combat radicals and effectively reduce oxidative stress. In this study, density functional theory was utilized to determine the anti-OOH activity, sequestration of free Cu(II) and Fe(III) ions, the potential pro-oxidative activity of the formed complexes, and the repairing capabilities toward essential biomolecules. The kinetic constants for scavenging of hydroperoxide radical were found to be low, with an order of magnitude not exceeding 10 −3 M −1 s −1 . Chelating properties showed slightly more satisfactory outcomes, although most complexes exhibited pro-oxidant activity. Pinocembrin, however, proved effective in repairing oxidatively damaged biological compounds and restoring their original functionality. The study found that whilst the system displays limited type I and type II antioxidant activity, it may support the role of physiological reductants already present in the biological matrix.

Unveiling the Antioxidative Potential of Galangin: Complete and Detailed Mechanistic Insights through Density Functional Theory Studies

“…Shifting to a water solvent, while Glg ( k overall = 6.21 × 10 4) is notably less efficient as a scavenger than ascorbate ( k overall = 1.00 × 10 8 ), but comparable to Trolox ( k overall = 8.96 × 10 4 ) or already mentioned scutellarein and its glycoside  scutellarin . In both media, Glg exhibits much better antiradical activity than pinocembrin, other closely related flavonoid.…”

“…Another observation worth underlining is the ambiguous effect of deprotonation: in the previous paper on pinocembrin, it has been evidenced to enhance activity in all the examples studied. Here, however, it is vague, and for example, while NF-Cys • is restored moderately by hydrogen transfer from C 5 of H 3 Glg ( k = 2.07 × 10 –3 M –1 s –1 ) or H 2 Glg – ( k = 5.48 × 10 –1 M –1 s –1 ), in the case of HGlg 2– , the rate of the process extremely increases, up to 7.52 × 10 8 M –1 s –1 .…”

Unveiling the Anti-Radical Potential of Galangin — A Detailed Density Functional Theory Investigation

“…The hydroxyl group at C7 exhibits the highest propensity for deprotonation, consistent with previous observations. [50][51][52][53] Additionally, the intramolecular hydrogen bonding with the carbonyl residue at C4, involving the acidic hydrogens of C3 and C5 groups, stabilizes the system, reducing the tendency for dissociation 54 . Therefore, the proposed deprotonation pathway is deemed reasonable.…”

“…58 Figure 2 illustrates two eH-DAMA maps, one in a nonpolar environment (upper, for pentyl ethanoate) and the other in a polar environment (lower, for water). These maps include reference substances (α-tocopherol, Trolox, ascorbic acid) and various flavonoids (isorhamnethin, scutellarein, apigenin, pinocembrin) [50][51][52][53] marked for comparative purposes.…”