Oleuropein: Molecular Dynamics and Computation

Background: Olive oil and table olive biophenols have been shown to significantly enrich the hedonic-sensory and nutritional quality of the Mediterranean diet. Oleuropein is one of the predominant biophenols in green olives and leaves, which not only has noteworthy freeradical quenching activity but also putatively reduces the incidence of various cancers. Clinical trials suggest that the consumption of extra virgin olive oil reduces the risk of several degenerative diseases. The oleuropein-based bioactives in olive oil could reduce tumor necrosis factor α, interleukin-1β and nitric oxide. Therefore, the quality of olive biophenols should be preserved and even improved due to their disease-fighting properties. Objective: Understanding the molecular dynamics of oleuropein is crucial to increase olive oil and table olive quality. The objective of this review is to provide the molecular dynamics and computational mapping of oleuropein. Method: The oleuropein molecular bond sequential breaking mechanisms were analyzed through unimolecular reactions under electron spray ionization, collision activated dissociations, and fast atom bombardment mass spectrometry. Results: Oleuropein is a biophenol-secoiridoid expressing different functionalities such as two π-bonds, two esters, two acetals, one catechol, and four hexose hydroxyls within 540 mw. The oleuropein solvent-free reactivity is leading to glucose loss and bioactive aglycone-dialdehydes via secoiridoid ring opening. Conclusion: Oleuropein electron distribution revealed that the free-radical non-polar processes occur from its highest occupied molecular orbital, while the lowest unoccupied molecular orbital is clearly devoted to nucleophilic and base site reactivity. This molecular dynamics and computational mapping of oleuropein could contribute to the engineering of olive-based biomedicine and/or functional food.