Oleuropein

Last updated
Oleuropein
Oleuropein structure.svg
Names
IUPAC name
Methyl (2S,3E,4S)-4-{2-[2-(3,4-Dihydroxyphenyl)ethoxy]-2-oxoethyl}-3-ethylidene-2-(β-D-glucopyranosyloxy)-2H-pyran-5-carboxylate
Systematic IUPAC name
Methyl (2S,3E,4S)-4-{2-[2-(3,4-Dihydroxyphenyl)ethoxy]-2-oxoethyl}-3-ethylidene-2-{[(2S,3R,4S,5S,6R)-3,4,5-trihydroxy-6-(hydroxymethyl)oxan-2-yl]oxy}-2H-pyran-5-carboxylate
Other names
2-(3,4-Dihydroxyphenyl)ethyl [(2S,3E,4S)-3-ethylidene-2-(β-D-glucopyranosyloxy)-5-(methoxycarbonyl)-3,4-dihydro-2H-pyran-4-yl]acetate
Identifiers
3D model (JSmol)
ChEMBL
ChemSpider
ECHA InfoCard 100.046.466 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/C25H32O13/c1-3-13-14(9-19(29)35-7-6-12-4-5-16(27)17(28)8-12)15(23(33)34-2)11-36-24(13)38-25-22(32)21(31)20(30)18(10-26)37-25/h3-5,8,11,14,18,20-22,24-28,30-32H,6-7,9-10H2,1-2H3/b13-3+/t14-,18+,20+,21-,22+,24-,25-/m0/s1 Yes check.svgY
    Key: RFWGABANNQMHMZ-ZCHJGGQASA-N Yes check.svgY
  • InChI=1/C25H32O13/c1-3-13-14(9-19(29)35-7-6-12-4-5-16(27)17(28)8-12)15(23(33)34-2)11-36-24(13)38-25-22(32)21(31)20(30)18(10-26)37-25/h3-5,8,11,14,18,20-22,24-28,30-32H,6-7,9-10H2,1-2H3/b13-3+/t14-,18+,20+,21-,22+,24-,25-/m0/s1
    Key: RFWGABANNQMHMZ-ZCHJGGQABE
  • O=C(OCCc1ccc(O)c(O)c1)C[C@H]2C(=C/C)\[C@@H](O\C=C2\C(=O)OC)O[C@@H]3O[C@@H]([C@@H](O)[C@H](O)[C@H]3O)CO
Properties
C25H32O13
Molar mass 540.518 g·mol−1
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
X mark.svgN  verify  (what is  Yes check.svgYX mark.svgN ?)

Oleuropein is a glycosylated seco-iridoid, a type of phenolic bitter compound found in green olive skin, flesh, seeds, and leaves. [1] The term oleuropein is derived from the botanical name of the olive tree, Olea europaea.

Contents

Because of its bitter taste, oleuropein must be completely removed or decomposed to make olives edible. During processing of bitter and inedible green olives for consumption as table olives, oleuropein is removed from olives via a number of methods, including by immersion in lye. [2] [3]

Chemical treatment

Oleuropein is a derivative of elenolic acid linked to the orthodiphenol hydroxytyrosol by an ester bond and to a molecule of glucose by a glycosidic bond. [4] When olives are immersed in a lye solution, the alkaline conditions lead to hydrolysis of the ester bond. The basic conditions also significantly increases the solubility of these derivatives, facilitating their release into the lye solution. [5] [6]

The high pH accelerates the oxidation of the phenolics, leading to blackness, as during their normal ripening, if the solution is oxygenated by air injection (alkaline oxidation of olives is also called the California process). [7] [8]

The lye solution is replaced several times until the bitter taste has dissipated. An alternative process uses amberlite macroporous resins to trap the oleuropein directly from the solution, reducing waste water while capturing the extracted molecules. [9] [10]

Enzymatic hydrolysis during the maturation of olives is also an important process for the decomposition of oleuropein and elimination of its bitter taste. [6] [11]

Green olive blackening

Green olives may be treated industrially with ferrous gluconate (0.4 wt. %) [7] to change their color to black. [12] Gluconate, an edible oxidation product of glucose, is used as non-toxic reactant to maintain Fe2+ in solution. When in contact with polyphenols, the ferrous ions form a black complex, giving the final color of the treated olives. [9] [10] [7] Black olives treated with iron(II) gluconate are also depleted in hydroxytyrosol, as iron salts are catalysts for its oxidation. [13]

Research

Oleuropein has been proposed as a proteasome activator. [14] [15]

See also

Related Research Articles

<span class="mw-page-title-main">Glucose</span> Naturally produced monosaccharide

Glucose is a sugar with the molecular formula C6H12O6. Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, using energy from sunlight, where it is used to make cellulose in cell walls, the most abundant carbohydrate in the world.

<span class="mw-page-title-main">Starch</span> Glucose polymer used as energy store in plants

Starch or amylum is a polymeric carbohydrate consisting of numerous glucose units joined by glycosidic bonds. This polysaccharide is produced by most green plants for energy storage. Worldwide, it is the most common carbohydrate in human diets, and is contained in large amounts in staple foods such as wheat, potatoes, maize (corn), rice, and cassava (manioc).

Benedict's reagent is a chemical reagent and complex mixture of sodium carbonate, sodium citrate, and copper(II) sulfate pentahydrate. It is often used in place of Fehling's solution to detect the presence of reducing sugars. The presence of other reducing substances also gives a positive result. Such tests that use this reagent are called the Benedict's tests. A positive test with Benedict's reagent is shown by a color change from clear blue to brick-red with a precipitate.

<span class="mw-page-title-main">Lignin</span> Structural phenolic polymer in plant cell walls

Lignin is a class of complex organic polymers that form key structural materials in the support tissues of most plants. Lignins are particularly important in the formation of cell walls, especially in wood and bark, because they lend rigidity and do not rot easily. Chemically, lignins are polymers made by cross-linking phenolic precursors.

<span class="mw-page-title-main">Gallic acid</span> 3,4,5-Trihydroxybenzoic acid

Gallic acid (also known as 3,4,5-trihydroxybenzoic acid) is a trihydroxybenzoic acid with the formula C6H2(OH)3CO2H. It is classified as a phenolic acid. It is found in gallnuts, sumac, witch hazel, tea leaves, oak bark, and other plants. It is a white solid, although samples are typically brown owing to partial oxidation. Salts and esters of gallic acid are termed "gallates".

<span class="mw-page-title-main">Polyphenol</span> Class of chemical compounds

Polyphenols are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include flavonoids, tannic acid, and ellagitannin, some of which have been used historically as dyes and for tanning garments.

<span class="mw-page-title-main">Glucose oxidase</span> Class of enzymes

The glucose oxidase enzyme also known as notatin is an oxidoreductase that catalyses the oxidation of glucose to hydrogen peroxide and D-glucono-δ-lactone. This enzyme is produced by certain species of fungi and insects and displays antibacterial activity when oxygen and glucose are present.

<span class="mw-page-title-main">Reducing sugar</span> Sugars that contain free OH group at the anomeric carbon atom

A reducing sugar is any sugar that is capable of acting as a reducing agent. In an alkaline solution, a reducing sugar forms some aldehyde or ketone, which allows it to act as a reducing agent, for example in Benedict's reagent. In such a reaction, the sugar becomes a carboxylic acid.

<span class="mw-page-title-main">Molisch's test</span>

Molisch's test is a sensitive chemical test, named after Austrian botanist Hans Molisch, for the presence of carbohydrates, based on the dehydration of the carbohydrate by sulfuric acid or hydrochloric acid to produce an aldehyde, which condenses with two molecules of a phenol, resulting in a violet ring.

<span class="mw-page-title-main">Gluconic acid</span> Chemical compound

Gluconic acid is an organic compound with molecular formula C6H12O7 and condensed structural formula HOCH2(CHOH)4CO2H. A white solid, it is forms the gluconate anion in neutral aqueous solution. The salts of gluconic acid are known as "gluconates". Gluconic acid, gluconate salts, and gluconate esters occur widely in nature because such species arise from the oxidation of glucose. Some drugs are injected in the form of gluconates.

<span class="mw-page-title-main">Lignocellulosic biomass</span>

Lignocellulose refers to plant dry matter (biomass), so called lignocellulosic biomass. It is the most abundantly available raw material on the Earth for the production of biofuels. It is composed of two kinds of carbohydrate polymers, cellulose and hemicellulose, and an aromatic-rich polymer called lignin. Any biomass rich in cellulose, hemicelluloses, and lignin are commonly referred to as lignocellulosic biomass. Each component has a distinct chemical behavior. Being a composite of three very different components makes the processing of lignocellulose challenging. The evolved resistance to degradation or even separation is referred to as recalcitrance. Overcoming this recalcitrance to produce useful, high value products requires a combination of heat, chemicals, enzymes, and microorganisms. These carbohydrate-containing polymers contain different sugar monomers and they are covalently bound to lignin.

<span class="mw-page-title-main">Hydroxytyrosol</span> Chemical compound

Hydroxytyrosol is an organic compound with the formula (HO)2C6H3CH2CH2OH. Classified as a phenylethanoid, i.e. a relative of phenethyl alcohol. Its derivatives are found in a variety of natural sources, notably olive oils and wines. Hydroxytyrosol is a colorless solid, although samples often turn beige during storage. It is a derivative, formally speaking, of catechol.

<span class="mw-page-title-main">Tyrosol</span> Chemical compound

Tyrosol is an organic compound with the formula HOC6H4CH2CH2OH. Classified as a phenylethanoid, i.e. a derivative of phenethyl alcohol, It is found in a variety of natural sources. The compound is colorless solid. The principal source in the human diet is olive oil.

<span class="mw-page-title-main">Olive leaf</span>

Olive leaf is the leaf of the olive tree. Although olive oil is well known for its flavor and possible health benefits, the leaf and its extracts remain under preliminary research with unknown effects on human health.

<span class="mw-page-title-main">Anthocyanin</span> Class of chemical compounds

Anthocyanins, also called anthocyans, are water-soluble vacuolar pigments that, depending on their pH, may appear red, purple, blue, or black. In 1835, the German pharmacist Ludwig Clamor Marquart gave the name Anthokyan to a chemical compound that gives flowers a blue color for the first time in his treatise "Die Farben der Blüthen". Food plants rich in anthocyanins include the blueberry, raspberry, black rice, and black soybean, among many others that are red, blue, purple, or black. Some of the colors of autumn leaves are derived from anthocyanins.

Benzaldehyde (C6H5CHO) is an organic compound consisting of a benzene ring with a formyl substituent. It is the simplest aromatic aldehyde and one of the most industrially useful.

<span class="mw-page-title-main">Elenolic acid</span> Chemical compound

Elenolic acid is a component of olive oil, olive infusion and olive leaf extract. It can be considered as a marker for maturation of olives.

<span class="mw-page-title-main">Blue bottle experiment</span> Color-changing redox chemical reaction

The blue bottle experiment is a color-changing redox chemical reaction. An aqueous solution containing glucose, sodium hydroxide, methylene blue is prepared in a closed bottle containing some air. Upon standing, it spontaneously turns from blue to colorless due to reduction of methylene blue by the alkaline glucose solution. However, shaking the bottle oxidizes methylene blue back into its blue form. With further shaking, this color-change cycle can be repeated many times. This experiment is a classic chemistry demonstration that can be used in laboratory courses as a general chemistry experiment to study chemical kinetics and reaction mechanism. The reaction also works with other reducing agents besides glucose and other redox indicator dyes besides methylene blue.

Divicine (2,6-diamino-4,5-dihydroxypyrimidine) is an oxidant and a base with alkaloidal properties found in fava beans and Lathyrus sativus. It is an aglycone of vicine. A common derivative is the diacetate form (2,6-diamino-1,6-dihydro-4,5-pyrimidinedione).

<span class="mw-page-title-main">Manzanilla olive</span> Type of olive

Manzanilla olives ("man-zah-nee-ya") or Manzanillo, also Manzanilla de Sevilla, originally from the area of Seville, Spain, are sometimes referred to as Spanish olives but along with Arbosana, Arbequina, Cacereña, Hojiblanca, Empeltre, and Gordal there are over two hundred varieties grown in Spain as well as other areas.

References

  1. ↑ Rupp R. (1 July 2016). "The bitter truth about olives". National Geographic. Archived from the original on 10 July 2019. Retrieved 24 June 2019.
  2. ↑ "How olives are made". California Olive Committee. 2017. Archived from the original on 5 August 2017. Retrieved 5 August 2017.
  3. ↑ Colmagro S.; Collins G.; Sedgley M. "Processing technology of the table olive" (PDF). Archived (PDF) from the original on 9 August 2017. Retrieved 25 June 2019.
  4. ↑ Panizzi, L.; Scarpati, M.L.; Oriente, E.G. (1960). "Structure of the bitter glucoside oleuropein. Note II". Gazzetta Chimica Italiana. 90: 1449–1485.
  5. ↑ Yuan, Jiao-Jiao; Wang, Cheng-Zhang; Ye, Jian-Zhong; Tao, Ran; Zhang, Yu-Si (2015). "Enzymatic hydrolysis of oleuropein from Olea Europea (olive) leaf extract and antioxidant activities". Molecules. 20 (2): 2903–2921. doi: 10.3390/molecules20022903 . ISSN   1420-3049. PMC   6272143 . PMID   25679050.
  6. 1 2 Ramírez, Eva; Brenes, Manuel; García, Pedro; Medina, Eduardo; Romero, Concepción (2016). "Oleuropein hydrolysis in natural green olives: Importance of the endogenous enzymes" (PDF). Food Chemistry. 206: 204–209. doi:10.1016/j.foodchem.2016.03.061. hdl: 10261/151764 . ISSN   0308-8146. PMID   27041317. Archived (PDF) from the original on 2018-07-23. Retrieved 2019-09-27.
  7. 1 2 3 El-Makhzangy, Attya; Ramadan-Hassanien, Mohamed Fawzy; Sulieman, Abdel-Rahman Mohamed (2008). "Darkening of brined olives by rapid alkaline oxidation". Journal of Food Processing and Preservation. 32 (4): 586–599. doi: 10.1111/j.1745-4549.2008.00198.x . ISSN   0145-8892.
  8. ↑ Ziena, H.M.S.; Youssef, M.M.; Aman, M.E. (1997). "Quality attributes of black olives as affected by different darkening methods". Food Chemistry. 60 (4): 501–508. doi:10.1016/S0308-8146(96)00354-8. ISSN   0308-8146.
  9. 1 2 "A 'greener' way to take the bitterness out of olives". phys.org. Archived from the original on 23 June 2019. Retrieved 23 June 2019.
  10. 1 2 Johnson, Rebecca; Mitchell, Alyson E. (2019). "Use of Amberlite macroporous resins to reduce bitterness in whole olives for improved processing sustainability". Journal of Agricultural and Food Chemistry. 67 (5): 1546–1553. doi:10.1021/acs.jafc.8b06014. ISSN   0021-8561. PMID   30636418. S2CID   58570570. Archived from the original on 2020-06-26. Retrieved 2021-05-18.
  11. ↑ Restuccia, Cristina; Muccilli, Serena; Palmeri, Rosa; Randazzo, Cinzia L.; Caggia, Cinzia; Spagna, Giovanni (2011). "An alkaline β-glucosidase isolated from an olive brine strain of Wickerhamomyces anomalus". FEMS Yeast Research. 11 (6): 487–493. doi: 10.1111/j.1567-1364.2011.00738.x . ISSN   1567-1356. PMID   21575132.
  12. ↑ Kumral, A.; Basoglu, F. (2008). "Darkening methods used in olive processing". Acta Horticulturae (791): 665–668. doi:10.17660/ActaHortic.2008.791.101. ISSN   0567-7572.
  13. ↑ Vincenzo Marsilio; Cristina Campestre; Barbara Lanza (July 2001). "Phenolic compounds change during California-style ripe olive processing". Food Chemistry. 74 (1): 55–60. doi:10.1016/S0308-8146(00)00338-1.
  14. ↑ Katsiki, Magda; Chondrogianni, Niki; Chinou, Ioanna; Rivett, A. Jennifer; Gonos, Efstathios S. (June 2007). "The olive constituent oleuropein exhibits proteasome stimulatory properties in vitro and confers life span extension of human embryonic fibroblasts". Rejuvenation Research. 10 (2): 157–172. doi:10.1089/rej.2006.0513. ISSN   1549-1684. PMID   17518699. Archived from the original on 2020-11-15. Retrieved 2020-10-15.
  15. ↑ Zou, Ke; Rouskin, Silvia; Dervishi, Kevin; McCormick, Mark A.; Sasikumar, Arjun; Deng, Changhui; Chen, Zhibing; Kaeberlein, Matt; Brem, Rachel B.; Polymenis, Michael; Kennedy, Brian K. (2020-08-01). "Life span extension by glucose restriction is abrogated by methionine supplementation: Cross-talk between glucose and methionine and implication of methionine as a key regulator of life span". Science Advances. 6 (32): eaba1306. Bibcode:2020SciA....6.1306Z. doi: 10.1126/sciadv.aba1306 . ISSN   2375-2548. PMC   7406366 . PMID   32821821.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.