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Polyphenols (/ ˌ p ɒ l i ˈ f iː n oʊ l,-n ɒ l /) are a large family of naturally occurring phenols. [1] They are abundant in plants and structurally diverse. [1] [2] [3] Polyphenols include phenolic acids, flavonoids, tannic acid, and ellagitannin, some of which have been used historically as dyes and for tanning garments.
In organic chemistry, phenols, sometimes called phenolics, are a class of chemical compounds consisting of one or more hydroxyl groups (−O H) bonded directly to an aromatic hydrocarbon group. [1] The simplest is phenol, C 6 H 5 OH. Phenolic compounds are classified as simple phenols or polyphenols based on the number of phenol units in the ...
The phenolic unit can be found dimerized or further polymerized, creating a new class of polyphenol. For example, ellagic acid is a dimer of gallic acid and forms the class of ellagitannins, or a catechin and a gallocatechin can combine to form the red compound theaflavin, a process that also results in the large class of brown thearubigins in tea.
Others, such as some polyphenols and flavonoids, may be pro-oxidants in high ingested amounts. [23] Non-digestible dietary fibers from plant foods, often considered as a phytochemical, [24] are now generally regarded as a nutrient group having approved health claims for reducing the risk of some types of cancer [25] and coronary heart disease. [26]
The main source of polyphenols is dietary, since they are found in a wide array of phytochemical-bearing foods.For example, honey; most legumes; fruits such as apples, blackberries, blueberries, cantaloupe, pomegranate, cherries, cranberries, grapes, pears, plums, raspberries, aronia berries, and strawberries (berries in general have high polyphenol content [5]) and vegetables such as broccoli ...
As part of their adaptation from marine life, terrestrial plants began producing non-marine antioxidants such as ascorbic acid (), polyphenols, and tocopherols.The evolution of angiosperm plants between 50 and 200 million years ago resulted in the development of many antioxidant pigments – particularly during the Jurassic period – as chemical defences against reactive oxygen species that ...
Resveratrol (3,5,4′-trihydroxy-trans-stilbene) is a stilbenoid, a type of natural phenol or polyphenol and a phytoalexin produced by several plants in response to injury or when the plant is under attack by pathogens, such as bacteria or fungi.
Polyphenol compounds may interact with volatiles and contribute to the aromas in wine. [49] Although wine polyphenols are speculated to provide antioxidant or other benefits, there is little evidence that wine polyphenols actually have any effect in humans.