Hydroxy-tyrosol glucosides

Tyrosol and hydroxy-tyrosol glucosides (Fig.6) constitute the principal part of minor phenolic components of olive. In fact, hydroxy-tyrosol 14 and tyrosol 18 are present in all parts of 0. europaea. It seems that glucose links all hydroxyls of phenol moiety without an evident... 

Hydroxy-tyrosol glucosides were isolated from different olive cultivars, and their relative quantities seem to be in relation with the olive organ considered [14],... 

In the olive, there are two main compounds, besides that reported in the literature. The first one is oleuropein, the first secoiridoid isolated in 1960 by Panizzi in Roma, as mentioned above. The second one is the comoside that is a hemiquinone glucoside, structurally and biogenetically related to hydroxy-tyrosol that is the principal free phenol in the olive. It should be remembered that, depending on the olive cultivar, the oleuropein can be prevalent against the comoside, or it could be the contrary, until reaching the equality. 

Comoside 11 is a glucoside that could be biogenetically related to hydroxy-tyrosol, the main phenolic component of O. europaea. 

Structures of compounds 15-17 were determined by spectroscopical method, essentially H- and 13C-NMR spectroscopy. Comparison between t3C-NMR data of glucosides 15-17 and hydroxy-tyrosol allowed to determine the site of glucosylation and therefore the structure of these compounds. 

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