Names | |
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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) | |
ChEBI | |
ChEMBL | |
ChemSpider | |
DrugBank | |
ECHA InfoCard | 100.114.418 |
EC Number |
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PubChem CID | |
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] | |
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). |
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.
Hydroxytyrosol and its derivatives occur in olives and in wines. [5] [6]
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]
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]
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]
Shortly after olive oil consumption, 98% of hydroxytyrosol in plasma and urine appears in conjugated forms (65% glucuronoconjugates), suggesting extensive first-past metabolism and a half-life of 2.43 hours. [13]
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]
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]
Olive oil is a liquid fat obtained by pressing whole olives, the fruit of Olea europaea, a traditional tree crop of the Mediterranean Basin, and extracting the oil.
The term Vitamin E refers to a group of eight molecular-structure related compounds that include four tocopherols and four tocotrienols. The tocopherols function as fat-soluble antioxidants which may help protect cell membranes from reactive oxygen species. Vitamin E is classified as an essential nutrient for humans. Various government organizations recommend that adults consume between 3 and 15 mg per day, while a 2016 worldwide review reported a median dietary intake of 6.2 mg per day. Sources rich in vitamin E include seeds, nuts, seed oils, peanut butter, vitamin E-fortified foods and dietary supplements. Symptomatic vitamin E deficiency is rare, is usually caused by an underlying problem with digesting dietary fat rather than from a diet low in vitamin E. Deficiency can cause neurological disorders.
Polyphenols are a large family of naturally occurring phenols. They are abundant in plants and structurally diverse. Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as dyes and for tanning garments.
Catechin is a flavan-3-ol, a type of secondary metabolite providing antioxidant roles in plants. It belongs to the subgroup of polyphenols called flavonoids.
Quercetin is a plant flavonol from the flavonoid group of polyphenols. It is found in many fruits, vegetables, leaves, seeds, and grains; capers, red onions, and kale are common foods containing appreciable amounts of it. It has a bitter flavor and is used as an ingredient in dietary supplements, beverages, and foods.
Isoflavones are substituted derivatives of isoflavone, a type of naturally occurring isoflavonoids, many of which act as phytoestrogens in mammals. Isoflavones occur in many plant species, but are especially high in soybeans.
Caffeic acid is an organic compound with the formula (HO)2C6H3CH=CHCO2H. It is a polyphenol. It is a yellow solid. Structurally, it is classified as a hydroxycinnamic acid. The molecule consists of both phenolic and acrylic functional groups. It is found in all plants as an intermediate in the biosynthesis of lignin, one of the principal components of biomass and its residues. It is unrelated to caffeine.
Oxygen radical absorbance capacity (ORAC) was a method of measuring antioxidant capacities in biological samples in vitro. Because no physiological proof in vivo existed in support of the free-radical theory or that ORAC provided information relevant to biological antioxidant potential, it was withdrawn in 2012.
Oleocanthal is a phenylethanoid, or a type of natural phenolic compound found in extra-virgin olive oil. It appears to be responsible for the burning sensation that occurs in the back of the throat when consuming such oil. Oleocanthal is a tyrosol ester and its chemical structure is related to oleuropein, also found in olive oil.
A polyphenol antioxidant is a hypothesized type of antioxidant studied in vitro. Numbering over 4,000 distinct chemical structures mostly from plants, such polyphenols have not been demonstrated to be antioxidants in vivo.
Tyrosol is an organic compound with the formula HOC6H4CH2CH2OH. Classified as a phenylethanoid, 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.
Epigallocatechin gallate (EGCG), also known as epigallocatechin-3-gallate, is the ester of epigallocatechin and gallic acid, and is a type of catechin.
Oleuropein is a glycosylated seco-iridoid, a type of phenolic bitter compound found in green olive skin, flesh, seeds, and leaves. The term oleuropein is derived from the botanical name of the olive tree, Olea europaea.
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.
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 named a chemical compound that gives flowers a blue color, Anthokyan, 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.
Phenolic compounds—natural phenol and polyphenols—occur naturally in wine. These include a large group of several hundred chemical compounds that affect the taste, color and mouthfeel of wine. These compounds include phenolic acids, stilbenoids, flavonols, dihydroflavonols, anthocyanins, flavanol monomers (catechins) and flavanol polymers (proanthocyanidins). This large group of natural phenols can be broadly separated into two categories, flavonoids and non-flavonoids. Flavonoids include the anthocyanins and tannins which contribute to the color and mouthfeel of the wine. The non-flavonoids include the stilbenoids such as resveratrol and phenolic acids such as benzoic, caffeic and cinnamic acids.
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.
The phenolic content in tea refers to the phenols and polyphenols, natural plant compounds which are found in tea. These chemical compounds affect the flavor and mouthfeel of tea. Polyphenols in tea include catechins, theaflavins, tannins, and flavonoids.
In biochemistry, naturally occurring phenols are natural products containing at least one phenol functional group. Phenolic compounds are produced by plants and microorganisms. Organisms sometimes synthesize phenolic compounds in response to ecological pressures such as pathogen and insect attack, UV radiation and wounding. As they are present in food consumed in human diets and in plants used in traditional medicine of several cultures, their role in human health and disease is a subject of research. Some phenols are germicidal and are used in formulating disinfectants.
From oxidative damage (ID 1333, 1638, 1639, 1696, 2865), maintenance of normal blood HDL cholesterol concentrations (ID 1639), maintenance of normal blood pressure (ID 3781), "anti-inflammatory properties" (ID 1882), "contributes to the upper respiratory tract health" (ID 3468), "can help to maintain a normal function of gastrointestinal tract" (3779), and "contributes to body defences against external agents" (ID 3467) pursuant to Article 13(1) of Regulation (EC) No 1924/2006