Homovanillyl Oleate, a Novel Lipophenol from Olive Plant with Antioxidant Properties

Lipophenols represent a significant form in which some phenolic compounds exist. In this work, the occurrence of homovanillyl oleate (HvOle) was investigated in primary olive matrices (drupes and leaves), olive oil, and byproducts (pomace and pate). The assay of HvOle was conducted by liquid chromatography-mass spectrometry (LC/MS). Our data demonstrate the presence of HvOle in all the matrices analyzed, including olives and leaves, in which other lipophenols were never detected so far. The radical scavenging properties of HvOle were assessed against 2,2-diphenyl-1-picrylhydrazyl (DPPH) and 2,2-azino bis(3-ethylbenzothiazoline-6-sulfonic) acid (ABTS) radicals. HvOle partly retained the activity of its parent compound homovanillyl alcohol (HvA). Furthermore, the antioxidant properties of HvOle were investigated in H2O2-treated HaCat human keratinocyte cell line. HvOle decreased the amount of malondialdehyde (MDA), a marker of lipid peroxidation, and the enzymatic activity of superoxide dismutase (SOD) without affecting glutathione-S-transferase (GST). HvOle reduces oxidative stress and can be potentially useful for the prevention or reduction of skin aging.