Oleocanthalic acid from extra-virgin olive oil: Analysis, preparative isolation and radical scavenging activity

Oleocanthal is a nutraceutical compound present in extra-virgin olive oil (EVOO), endowed with several health properties, such as anti-inflammatory, neuroprotective and anticancer effects. During the EVOO storage, oleocanthal can undergo oxidative processes that lead to the formation of oleocanthalic acid. The aim of this work was to develop a reproducible and efficient method for isolation and purification of oleocanthalic acid with the purpose to obtain enough amount of this compound for further pharmacological investigations. We heated an EVOO rich in oleocanthal at 80 °C for 14 days to favour the oxidation of oleocanthal. Subsequently, the oleocanthalic acid was extracted from this EVOO and purified through a combination of direct phase and reverse phase chromatography. The pure oleocanthalic acid was used to develop a HPLC method for qualitative and quantitative analysis of oleocanthalic acid content in EVOO. A preliminary assessment of the radical scavenging potential against oxygen species (superoxide anion radical (O2[rad]−), hypochlorous acid (HOCl) and peroxyl radical (ROO[rad])) was also screened. The results showed the quenching efficiency of oleocanthalic acid for HOCl followed by O2[rad]−.