Polyphenols

290px|thumb|Representative chemical structure of one of many plant-derived polyphenols that comprise tannic acid. Such compounds are formed by esterification of [[phenylpropanoid-derived gallic acid to a monosaccharide (glucose) core.]] 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.

Haematoxylin or hematoxylin (), also called natural black 1 or C.I. 75290, is a compound extracted from heartwood of the logwood tree (Haematoxylum campechianum) with a chemical formula of . This naturally derived dye has been used as a histologic stain, as an ink and as a dye in the textile and leather industry. As a dye, haematoxylin has been called palo de Campeche, logwood extract, bluewood and blackwood. In histology, haematoxylin staining is commonly followed by counterstaining with eosin. When paired, this staining procedure is known as H&E staining and is one of the most commonly used

Rutin (rutoside, quercetin-3-O-rutinoside or sophorin) is the glycoside combining the flavonol quercetin and the disaccharide rutinose (α-L-rhamnopyranosyl-(1→6)-β-D-glucopyranose). It is a flavonoid glycoside found in a wide variety of plants, including citrus.

thumb|Red, blue, and purple colors of berries derive mainly from polyphenol phytochemicals called [[anthocyanins.]] thumb|Cucurbita fruits, including squash and [[pumpkin, typically have high content of the phytochemical pigments called carotenoids.]]

chemical compound

Benzenehexol, also called hexahydroxybenzene, is an organic compound with formula or . It is a six-fold phenol of benzene. The product is also called hexaphenol, but this name has been used also for other substances.

fluorescent reagent used in analytical chemistry

thumb|right|250px|Chemical structure of flavan-3-ol

Wine chemistry

class=skin-invert-image|thumb|right|upright|Gyrophoric acid, a depside

Tetrahydroxy-1,4-benzoquinone, also called 'tetrahydroxy-p-benzoquinone, tetrahydroxybenzoquinone, or tetrahydroxyquinone' (THBQ, THQ), is an organic compound with formula . Its molecular structure consists of a cyclohexadiene ring with four hydroxyl groups and two ketone groups in opposite (para) positions.

Nothofagin is a dihydrochalcone. It is a C-linked phloretin glucoside found in rooibos (Aspalathus linearis) and New Zealand red beech (Nothofagus fusca). It is a phenolic antioxidant.

Atromentin is a natural chemical compound found in Agaricomycetes fungi in the orders Agaricales and Thelephorales. It can also be prepared by laboratory synthesis. Chemically, it is a polyphenol and a benzoquinone.

chemical compound

Purpurogallin is an aglycone natural product. It is an orange-red solid that is soluble in polar organic solvents but not in water. Its glycoside (ether-linked to sugar), called dryophantin, is found in nutgalls and oak barks. Purpurogallin can be prepared by oxidation of pyrogallol with sodium periodate.

hypothetical type of antioxidant

chemical compound

Quebecol is a polyphenolic chemical compound that has been isolated from maple syrup. It has the chemical formula C24H26O7 and the systematic name 2,3,3-tri-(3-methoxy-4-hydroxyphenyl)-1-propanol. Analysis of maple sap before it is converted into syrup suggests that this compound is not naturally present in the sap but, instead, is formed during extraction or processing. A total synthesis of the compound was reported in 2013.