Hydroxytyrosol
Chemical compound
From Wikipedia, the free encyclopedia
Hydroxytyrosol is an organic compound with the formula (HO)2C6H3CH2CH2OH. It is 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,[3][4] although samples often turn beige during storage. It is a derivative, formally speaking, of catechol.
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| Names | |
|---|---|
| Preferred IUPAC name
4-(2-Hydroxyethyl)benzene-1,2-diol | |
| Other names
3-Hydroxytyrosol 3,4-dihydroxyphenylethanol (DOPET) Dihydroxyphenylethanol 2-(3,4-Di-hydroxyphenyl)-ethanol (DHPE) 3,4-dihydroxyphenolethanol (3,4-DHPEA)[1] | |
| Identifiers | |
3D model (JSmol) |
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| ChEBI | |
| ChEMBL | |
| ChemSpider | |
| DrugBank | |
| ECHA InfoCard | 100.114.418 |
| EC Number |
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PubChem CID |
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| UNII | |
CompTox Dashboard (EPA) |
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| Properties | |
| C8H10O3 | |
| Molar mass | 154.165 g·mol−1 |
| Appearance | colorless solid |
| 5 g/100 ml | |
| Hazards | |
| Occupational safety and health (OHS/OSH): | |
Main hazards |
Causes skin irritation.
Causes serious eye irritation. May cause respiratory irritation. |
| GHS labelling:[2] | |
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| Warning | |
| H315, H319, H335 | |
| P261, P264, P271, P280, P302+P352, P304+P340, P305+P351+P338, P312, P321, P332+P313, P337+P313, P362, P403+P233, P405, P501 | |
| Safety data sheet (SDS) | |
| Related compounds | |
Related alcohols |
benzyl alcohol, tyrosol |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Hydroxytyrosol and its derivatives occur in olives and in wines.[5][6]
Occurrence
Olives
The olives, leaves, and olive pulp contain large amounts of hydroxytyrosol derivative oleuropein, more so than olive oil.[1] Unprocessed, green (unripe) olives contain between 4.3 and 116 mg of hydroxytyrosol per 100 g of olives, while unprocessed, black (ripe) olives contain up to 413.3 mg per 100 g.[7] The ripening of an olive substantially increases the amount of hydroxytyrosol.[8] Processed olives, such as the common canned variety containing iron(II) gluconate, contain little hydroxytyrosol, as iron salts are catalysts for its oxidation.[9]
Food safety
Hydroxytyrosol is considered safe as a novel food for human consumption, with a no-observed-adverse-effect level of 50 mg/kg body weight per day, as evaluated by the European Food Safety Authority (EFSA).[10]
In the United States, hydroxytyrosol is considered to be a safe ingredient (GRAS) in processed foods at levels of 5 mg per serving.[11]
Function and production
In nature, hydroxytyrosol is generated by the hydrolysis of oleuropein that occurs during olive ripening. Oleuropein accumulates in olive leaves and fruit as a defense mechanism against pathogens and herbivores. During olive ripening or when the olive tissue is damaged by pathogens, herbivores, or mechanical damage, the enzyme β-glucosidase catalyzes hydroxytyrosol synthesis via hydrolysis from oleuropein.[12]
Metabolism
Shortly after olive oil consumption, 98% of hydroxytyrosol in plasma and urine appears in conjugated forms (65% glucuronoconjugates), suggesting extensive first-pass metabolism and a half-life of 2.43 hours.[13]
Mediterranean diet
Mediterranean diets, characterized by regular intake of olive oil, have been shown to positively affect human health, including reduced rates of cardiovascular diseases.[5][14][15] Research on consumption of olive oil and its components includes hydroxytyrosol and oleuropein, which may inhibit oxidation of LDL cholesterol – a risk factor for atherosclerosis, heart attack or stroke.[16] The daily intake of hydroxytyrosol within the Mediterranean diet is estimated to be between 0.15 and 30 mg.[17]
Regulation
Europe
The EFSA has issued a scientific opinion on health claims in relation to dietary consumption of hydroxytyrosol and related polyphenol compounds from olive fruit and oil, and protection of blood lipids from potential oxidative damage.[18]
EFSA concluded that a cause-and-effect relationship existed between the consumption of hydroxytyrosol and related compounds from olives and olive oil and protection of blood lipids from oxidative damage,[18] providing a health claim for consumption of olive oil polyphenols containing at least 5 mg of hydroxytyrosol and its derivatives (oleuropein complex and tyrosol) per 20 g of olive oil.[18]
See also
- Echinacoside, a hydroxytyrosol-containing glycoside
- Tyrosol
- Verbascoside, another hydroxytyrosol-containing glycoside
- Resveratrol