New iridoid derivatives from table olives cv Throuba Thassos and olive mill waste waters

Through a phytochemical screening of ten commercially available types of Greek table olives, a variety of naturally black dry salted olives cv. Throuba Thassos was found to be comparatively a very rich source of polyphenols and iridoid derivatives. Subsequent extensive phytochemical study of the methanolic extract led to the isolation of 16 natural products identified by NMR and MS spectroscopy. Among them, a macrocyclic analogue of oleuropein, named Fraxamoside B (1) and 2-[5-eth-(E)-ylidene-2-oxo-tetrahydro-pyranyl-4] acrylic acid methyl ester (oleone) (2) are new natural products [1]. Cornoside, 4-O glycoside of hydroxytyrosol and oleuropein along with (5-ethylidene-2-oxo-tetrahydro-pyranyl-4) acetic acid (lactone), 2-(5 -ethylidene-2-oxo-tetrahydro-pyranyl-4) acetic acid methyl ester (3), 3-methoxy tyrosol, are products that have not been reported in edible olives [2]. The known compounds hydroxytyrosol, tyrosol, glycoside of tyrosol, 11-oleoside methylester, ligstroside, catechol, oleanolic and maslinic acid were also isolated. Compounds 2 and 3 were also isolated from olive mill waste water (OMWW) treated with XAD resins [3]. From the same source one more compound named oleolactone (4) was for the first time isolated as a natural product.

References: 1. Takenaka, Y. et al. (2000) Phytochemistry 55:275–284 2. Bianchi, G. (2003) Eur. J. lipid Sci. Technol. 105: 229–242 3. Agalias, A. (2007)J Agric Food Chem 55: 2671–2676