Semiempirical Molecular Modeling into Quercetin Reactive Site:  Structural, Conformational, and Electronic Features

Abstract

The conformational behavior, molecular geometry and electronic structure of quercetin were investigated using the semiempirical AM1 and PM3 methods. Results reveal that quercetin has a nonplanar molecular structure, with cross-conjugation occurring at the C ring. Calculations were also performed for quercetin radical species at the OH groups, showing the presence of three radicals in a narrow range of energy. An interpretation of the antioxidative process mechanism, exerted by quercetin as a free radical scavenger, relies on two isoenergetic radicals with extended electronic delocalization between adjacent rings, also having cross-conjugated systems and being affected by the experimental environment influencing their relative order.

Flavones Inhibit LPS-Induced Atrogin-1/MAFbx Expression in Mouse C2C12 Skeletal Myotubes

“…The antioxidant properties of flavonoids are widely recognized (30,31). The three classical antioxidant structural features of flavonoids are the presence of a B ring catechol group, the presence of a C2-C3 double bond in conjugation with an oxo group at C4 and the presence of both 3-OH and 5-OH (32)(33)(34).…”

Effect of porogenic solvent on selective performance of molecularly imprinted polymer for quercetin

“…Among the falconoid, quercetin has five hydroxyl groups attached to the aromatic rings, along with the electronic delocalization throughout the whole system, which results from the formation of stable radicals 10 . As commonly known, hydrophobic interactions are one of the binding mechanisms in order to efficiently recognize the template molecules during MIP selection process.…”

“…It is the most active compound in flavone class and widely exists in leaves, fruits, and flowers of many plants 9 . Quercetin is a natural antioxidant because its hydroxyl groups attached to the aromatic rings can quench the active free radical 10 . Since it has low concentration and structural similarity to other flavonols in natural states, it is very difficult to determine and separate.…”

Quercetin molecularly imprinted polymers: Preparation, recognition characteristics and properties as sorbent for solid-phase extraction

“…Quercetin has now become the topic of increasing interest based on its various bioactivities such as inoxidability, antiviral property, antitumor and adjusting the immune function [18], as well as its chemical applications, e.g., quercetin is immobilized on silica gel and used as a solid-phase reagent for tin (IV) determination [19]. The determination of quercetin is typically performed with HPLC-UV [15,20,21], besides electrogenerated chemiluminescence (ECL) [22] and capillary electrophoresis (CE) [23].…”