Computational Chemistry Strategies to Investigate the Antioxidant Activity of Flavonoids-An Overview.

Despite several decades of research, the beneficial effect of flavonoids on health is still enigmatic. Here, we focus on the antioxidant effect of flavonoids, which is elementary to their biological activity. A relatively new strategy for obtaining a more accurate understanding of this effect is to leverage computational chemistry.

Unraveling the Antioxidant Activity of ,-dihydroquercetin.

It has been reported that in an oxidative environment, the flavonoid ,-dihydroquercetin (,-DHQ) oxidizes into a product that rearranges to form quercetin. As quercetin is a very potent antioxidant, much better than ,-DHQ, this would be an intriguing form of targeting the antioxidant quercetin. The aim of the present study is to further elaborate on this targeting.

Flavonoids Seen through the Energy Perspective.

In all life forms, opposing forces provide the energy that flows through networks in an organism, which fuels life. In this concept, health is the ability of an organism to maintain the balance between these opposing forces, which creates resilience, and a deranged flow of energy is the basis for diseases. Treatment should focus on adjusting the deranged flow of energy, e.

The Flow of the Redox Energy in Quercetin during Its Antioxidant Activity in Water.

Most studies on the antioxidant activity of flavonoids like Quercetin (Q) do not consider that it comprises a series of sequential reactions. Therefore, the present study examines how the redox energy flows through the molecule during Q's antioxidant activity, by combining experimental data with quantum calculations. It appears that several main pathways are possible.

Delocalization of the Unpaired Electron in the Quercetin Radical: Comparison of Experimental ESR Data with DFT Calculations.

In the antioxidant activity of quercetin (Q), stabilization of the energy in the quercetin radical (Q) by delocalization of the unpaired electron (UE) in Q is pivotal. The aim of this study is to further examine the delocalization of the UE in Q, and to elucidate the importance of the functional groups of Q for the stabilization of the UE by combining experimentally obtained spin resonance spectroscopy (ESR) measurements with theoretical density functional theory (DFT) calculations. The ESR spectrum and DFT calculation of Q and structurally related radicals both suggest that the UE of Q is mostly delocalized in the B ring and partly on the AC ring.