Session: General Poster:

Vitamin E (α-tocopherol) is a vital antioxidant that protects lipid structures in living cells from being damaged by reactive oxygen species (ROS). Dietary flavones and isoflavones that bear catechol (ortho-dihydroxy) groups also scavenge ROS at a significant rate and may prevent Vitamin E depletion. There is evidence that catechol-flavonoids may have a protective role in cellular models of Alzheimer’s disease (AD), Parkinson’s disease (PD) and Huntington’s disease (HD). Using a Mn²⁺ titration assay, based on ¹H-NMR spectroscopy, it was previously demonstrated that daidzein (7,4’-dihydroxy-isoflavone) incorporated into aqueous sodium dodecyl sulfate (SDS) micelles and occupied a time-average location near the sulfate “head” groups. In contrast genistein (5,7,4’-trihydroxy-isoflavone) incorporated into SDS micelles but was located within the hydrophobic micelle core. The results from the assay of quercetin, rutin, 7,3’4’-trihydroxy-isoflavone (7,3’,4’-THIF) and pomiferin are now reported. Quercetin and pomiferin both were located within the hydrophobic micelle core. In contrast, 7,3’,4’-THIF (3’-hydroxy-daidzein) was located near the aqueous interface, much like daidzein. Rutin was located at the aqueous interface with the rutinose portion exposed to the aqueous phase and the aromatic flavone portion buried within the hydrophobic micelle core. Each catechol-flavone or catechol-isoflavone reacted with 2,2-diphenyl-1-picrylhydrazyl (DPPH) radical in methanol solution and exhibited an IC₅₀ value in the range of 5 μM to 20 μM. The aqueous SDS micelle system could be used as a model to investigate how the position and orientation of flavonoids in lipid structures may affect scavenging of ROS.

Cody Wommack

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