Details

Autor(en) / Beteiligte

• Atala, Elias
• Fuentes, Jocelyn
• Jose Wehrhahn, Maria
• Speisky, Hernan

Titel

190 - Oxidation of Quercetin and Its Structural Analogues Differentially Affects Its Antioxidant Properties

Ist Teil von

• Free radical biology & medicine, 2016-11, Vol.100, p.S93-S93

Ort / Verlag

Elsevier Inc

Erscheinungsjahr

2016

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• We addressed whether the oxidation of quercetin (Q) necessarily leads to the loss of its antioxidant properties. Towards that end, the reactive oxygen species (ROS)-scavenging (ORAC), the Folin-Ciocalteau(FC)- and Fe-reducing capacities of quercetin, and that of thirteen other structurally-related flavonoids, was assessed following their exposure to oxidative conditions. Oxidation was chemically-induced by direct dissolution of each flavonoid in an alkaline medium (pH12, 0-300 min). HPLC-DAD analyses revealed that the flavonoids exhibiting a HO group in the C3-ringC position in conjugation with a HO in C3’-4’-ringB were the fastest in disappearing. Those lacking a HO in C3-ringC, and those containing no catechol in the B-ring underwent either a slower and/or an only partial disappearance within 300 min. After its total disappearance, the mixture containing the Q-derived oxidation products was found to retain 95%, 77% and 77% of its original ORAC, FC- and Fe-reducing capacities. Analogues containing a flavonol structure conserve at least 82% of their ORAC values; excepting for catechins and eriodictyol (which exhibited near 50%), all other tested flavonoids retained at least 69% of their ORAC. Between 51% and 95% of the original FC-reducing capacity and between 12% and 68% of the original Fe-reducing capacity was retained by all tested flavonoids. Present results are first in reporting that the mixtures resulting from the chemical-induced oxidation of either quercetin or some of its structurally-related analogues, are able to largely conserve their ROS-scavenging and redox properties. Ongoing studies are being conducted to further establish the identity of the some of the oxidized metabolites which account for retained antioxidant activity. Fondecyt #1150090/3150359