Modern solid support free liquid-liquid techniques turn EVOO to a pool of new natural products and provide gram scale isolation of high importance biophenols

Olive oil is straightly correlated with the Mediterranean diet and the providing health benefits. Most of the beneficial characteristics of EVOO are attributed to olive oil biophenols which compose the Total Phenolic Fraction (TPF). In previous studies of our group, solid support free liquid-liquid extraction and chromatography techniques, were performed on laboratory scale for the extraction of TPF and the further fractionation of EVOO biophenols as well. Following this process, enriched fractions of high importance molecules like oleocanthal, oleacein, MFLA, MFOA, elenolic acid and hydroxytyrosol have been produced. In addition, new natural compounds presented as minor TPF constituents (elenolic acid ethylester, oleocanthalic acid, oleaceinic acids and EDA acid), were isolated1,2. In the present continuing study, a pilot scale extraction process was developed using Annular Centrifugal Extraction, resulting in the recovery of large amount of TPF. This pilot step gave us the opportunity not only to isolate high quantities of the above mention compounds, but also to investigate the extract chemical composition in deep. The preparative CPC fractionation following by preparative HPLC analysis of the enriched CPC fractions resulted in the gram-scale recovery of the major TPF secoiridoids in a purity higher than 98%. Moreover, three new minor TPF constituents ((9E, 11E)-13-oxotrideca-9,11-diencoic acid, ligstroside aglycon ethyl ester and EDA lactone) have been isolated. The structure elucidation was performed using NMR and UPLC-HRMS analysis. This holistic extraction and isolation methodology is well promising for the identification of EVOO molecules and make them available for in vivo tests and clinical studies.

Fig. 1 Schematic diagram of isolation process

• References

• 1 Angelis A, Hamzaoui M, Aligiannis N, Nikou T, Michailidis D, Gerolimatos P. et al. An integrated process for the recovery of high added-value compounds from olive oil using solid support free liquid-liquid extraction and chromatography techniques. J Chromatogr A 2017; 1491: 126-136
• 2 Angelis A, Antoniadi L, Stathopoulos P, Halabalaki M, Skaltsounis LA. Oleocanthalic and Oleaceinic acids: New compounds from Extra Virgin Olive Oil (EVOO). Phytochem Lett 2018; 26 , August: 190–194. DOI: 10.1016/j.phytol.2018.06.020.