Optimization of Oleuropein Extraction from Olive Leaves. Alternative approaches for the recovery of olive bioactive secoiridoids.

Oleuropein (OLE) is the major secoiridoid of olive leaves with established beneficial effects on human health, proven by numerous scientific data, with cardioprotective properties to distinguish amongst others. Since olive leaves is one of the richest sources of OLE, there are several studies available in the literature regarding different methods and approaches for its isolation. In the present work, the impact of row material treatment (olive leaves drying conditions) and extraction method on OLE recovery from olive leaves, was investigated. Based on our results it was shown that the obtained OLE levels are strongly dependent on the drying protocol of leaves prior any treatment, as well as the method which is followed for the extraction, and more specifically the extraction solvent, the temperature and the pH. Additionally, it was evident that these factors also affect considerably the secondary metabolites content generally, qualitatively, and quantitatively. Indeed, based on the conditions used, new secoiridoids were detected, isolated, and finally identified by means of NMR and HRMS.

Overall, in the context of the present study, it was possible to develop an optimum protocol for the recovery of OLE from olives leaves, as well as to point out the high impact of different parameters related to starting material treatment and extraction protocols, towards the investigation of secondary metabolites in plants.

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Artikel online veröffentlicht:
13. Dezember 2021