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) | |
ChEBI | |
ChEMBL | |
ChemSpider | |
DrugBank | |
ECHA InfoCard | 100.114.418 |
EC Number |
|
PubChem CID | |
UNII | |
CompTox Dashboard (EPA) | |
| |
| |
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. Contents |
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.
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 100g of olives, while unprocessed, black (ripe) olives contain up to 413.3 mg per 100g. [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, contained 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. [19]
Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols. Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vitamin E, can cause nerve problems. Vitamin E is a fat-soluble antioxidant which may help protect cell membranes from reactive oxygen species. Worldwide, government organizations recommend adults consume in the range of 3 to 15 mg per day. As of 2016, consumption was below recommendations according to a worldwide summary of more than one hundred studies that reported a median dietary intake of 6.2 mg per day for alpha-tocopherol.
Tocopherols are a class of organic compounds comprising various methylated phenols, many of which have vitamin E activity. Because the vitamin activity was first identified in 1936 from a dietary fertility factor in rats, it was named tocopherol, from Greek τόκοςtókos 'birth' and φέρεινphérein 'to bear or carry', that is 'to carry a pregnancy', with the ending -ol signifying its status as a chemical alcohol.
Flavonoids are a class of polyphenolic secondary metabolites found in plants, and thus commonly consumed in the diets of humans.
Flavan-3-ols are a subgroup of flavonoids. They are derivatives of flavans that possess a 2-phenyl-3,4-dihydro-2H-chromen-3-ol skeleton. Flavan-3-ols are structurally diverse and include a range of compounds, such as catechin, epicatechin gallate, epigallocatechin, epigallocatechin gallate, proanthocyanidins, theaflavins, thearubigins. They play a part in plant defense and are present in the majority of plants.
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.
Isoflavones are substituted derivatives of isoflavone, a type of naturally occurring isoflavonoids, many of which act as phytoestrogens in mammals. Isoflavones are produced almost exclusively by the members of the bean family, Fabaceae (Leguminosae).
Caffeic acid is an organic compound that is classified as a hydroxycinnamic acid. This yellow solid consists of both phenolic and acrylic functional groups. It is found in all plants because it is an intermediate in the biosynthesis of lignin, one of the principal components of woody plant biomass and its residues.
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 hypothetized type of antioxidant, in which each instance would contain a polyphenolic substructure; such instances which have been studied in vitro. Numbering over 4,000 distinct chemical structures, such polyphenols may have antioxidant activity {{{1}}} in vitro (although they are unlikely to be antioxidants in vivo). Hypothetically, they may affect cell-to-cell signaling, receptor sensitivity, inflammatory enzyme activity or gene regulation, although high-quality clinical research has not confirmed any of these possible effects in humans as of 2020.
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.
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 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.
The phenolic content in wine refers to the phenolic compounds—natural phenol and polyphenols—in wine, which 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