Oleuropein

A traditional system for the preparation of table olives, involves a treatment of the fresh fruit with a solution of NaOH to hydrolised the bitter glycoside oleuropein, followed by a lactic fermentation in brine. The modifications that take place on pectic polysaccharides of olives (Manzanilla variety) during this process was smdied. Processing induced a net loss of polysaccharides soluble in sodium carbonate and a paralel accumulation of water and Imidazole/HCl soluble polysaccharides. A general decrease of the apparent molecular weight of water and carbonate soluble polysaccharides was also detected. 

Secoiridoids are complex phenols produced from the secondary metabolism of terpenes as precursors of several indole alkaloids (Soler-Rivas and others 2000). They are characterized by the presence of elenolic acid, in its glucosidic or aglyconic form, in their molecular structure. Oleuropein, the best-known secoiridoid, is a heterosidic ester of elenolic acid and 3,4- dihydroxyphenylethanol containing a molecule of glucose, the hydrolysis of which yields elenolic acid and hydroxytyrosol (Soler-Rivas and others 2000). 

Oleuropein (the most abundant bitter principle) and its analog ligstroside, both sec-oiridoid biophenols, were extracted from Hojiblanca black olives (Piperno and others 2004). Secoiridoids are present exclusively in plants of the Oleraceae family (Tripoli and others 2005). Oleuropein is present in high amounts (6000 90 mg/100 g DW) in the leaves of the olive tree (Le Tutour and others 1992), but it is also present in all constituent parts of the fruit peel, pulp, and seed (Servili and others 1999). 

Soler-Rivas C, Espin JC and Wichers HJ. 2000. Oleuropein and related compounds. J Sci Food Agric 80(7) 1013-1023. 

Landete and others (2009) reported that Lactobacillus plantarum have the ability to metabolize phenolic compounds found in olive products (such as oleuropein, hydroxytyrosol, and tyrosol, as well as vanillic, p-hydroxybenzoic, sinapic, syringic, protocatechuic, and cinnamic acids). For example, oleuropein was metabolized mainly to hydroxytyrosol, whereas protocatechuic acid was decarboxylated to catechol by the enzymatic actions. 

The amino acid composition of the environment also plays an important role. Valine is required for the outgrowth of S. aureus, arginine and cysteine, for the production of SEA, SEB, and SEC (Onoue and Mori, 1997). A low concentration of oleuropein (0.1%) - a phenol compound extracted from olives - retards the growth of S. aureus. Higher concentrations (>0.2%) inhibit completely the growth and production of enterotoxins (Tranter et al., 1993). 

Tranter, H.S., Tassou, S.C. and Nychas, G.J., The eflect of the olive phenolic compound, oleuropein, on growth and enterotoxin B production by Staphylococcus aureus, J. Appl. Bacterial., 74, 253-9, 1993. 

Oleoside-7-methyl ester Lf IS EOiO Oleuropein, dimethyl Fr° ° , Bk 15°eo70 LPE151, KemepE0 ... 

Oleuropein , a new glucoside from Olea europaea L. J Pharm Chim 1938 ... 

Bianco, A. D., I. Muzzalupo, A. Pipemo, G. Romeo, and N. Uccella. Bioactive derivatives oleuropein from olive fruits. J Agr Food Chem 1999 47(9) 3531-3534. 

Perri, E., A. Raffaelli, and G. Sindona. OE067 Quantitation of oleuropein in virgin olive oil by ionspray mass spectrometry-selected reaction monitoring. J OE068 Agr Food Chem 1999 47(10) 4156-4160. 

OEl 65 Occhiuto, F., C. Circosta, A. Gregorio, and G. Busa. Olea europaea L. and oleuropein effects on excito-conduc-tion and on monophasic action potential in anesthetized dogs. Phytother... 

A. Saija. On the in vitro antimicrobial activity of oleuropein and hydroxytyrosol. J Pharm Pharmacol 1999 51(8) 971-974. 

Oleuropein, a conjugate of hydroxytyrosol (3,4-dihydroxybenzyl alcohol), is a characteristic but very variable component of olives and olive oil. After consumption of 25 ml virgin olive oil, hydroxytyrosol, 3-(9-methylhydroxytyrosol (homovanillyl alcohol), and homovanillic acid increase in plasma, as conjugates, predominantly glucuronide ° Oleuropein may be deconjugated by the gut microflora. 

Oleuropein, a secoiridoid glycoside Fraxinus excelsior (ash tree), Olea europaea (olive tree) and Ligustrum obtusifolium from the family Oleaceae are the major sources of oleuropein. This compound has hypotensive. 

Also, the phenolic compounds in olives have a strong influence on the flavor of the oil and seem to be responsible for the high oxidation resistance of olive oil. The phenolic content in the flesh of olive fruits ranges between 1% and 3%, w/w, (66) oleuropein, vanillic, caffeic, p-coumaric acid, rutin, luteolin-7-glucoside, heterosidic ester of caffeic acid, and hydroxytyrosol (verbascoside) have been identified in olive fruits. 

The olives themselves contain many phenolic compounds with antioxidant properties. Bouaziz et al. (2005) investigated the olive cultivar Chemlali from Tunisia. Oleuropein (7.14), a bitter glycoside esterified with a phenolic acid, was the major compound present. Phenolic monomers and twelve flavonoids were also identified. The antioxidant activity of the extract was evaluated. Acid hydrolysis of the extract enhanced its antioxidant activity. / -Hydroxyphenyl-cthanol (7.12) and quercetin (1.43) showed antioxidant activities similar to that of 2,6-di-fert-butyl-4-methyl phenol (7.15), a reference compound with known antioxidant properties. It was suggested that a hydroxyl group at the ortho-position on the flavonoid B ring could contribute to the antioxidant activity of the flavonoids. 

The first NMR study of olive oil components appeared in 1993 by the Montedoro group (Montedoro et ah, 1993), in which three extracted poly-phenolic compounds (one isomer of oleuropein aglycone, the dialdehydic... 

Konno, K., Hirayama, C., Yasui, H., and Nakamura, M., Enzymatic activation of oleuropein A protein crosslinker used as a chemical defense in the privet tree, Proc. Nat. Acad. Sci. USA, 96, 9159, 1999. 

Stupans I, Murray M, Kirlich A, et al. Inactivation of cytochrome P450 by the food-derived complex phenol oleuropein. Food Chem Toxicol 2001 39(11) 1119-1124. 

Oleuropein (seco-iridoid glycoside) Olea europaea (Oleaceae) ACE (38% inhibition at 300 UM) [76]... 

Figure 12 Enzymatic activation of oleuropein in the defense system of the privet tree Ligustrum obtusifolium and adaptation of privet specialist insects.

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