Tannins are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids.
Immunoglobulin M (IgM) is the largest of several isotypes of antibodies that are produced by vertebrates. IgM is the first antibody to appear in the response to initial exposure to an antigen; causing it to also be called an acute phase antibody. In humans and other mammals that have been studied, plasmablasts in the spleen are the main source of specific IgM production.
Linaceae is a family of flowering plants. The family is cosmopolitan, and includes about 250 species in 14 genera, classified into two subfamilies: the Linoideae and Hugonioideae. Leaves of the Linaceae are always simple; arrangement varies from alternate to opposite or whorled. The hermaphroditic, actinomorphic flowers are pentameric or, very rarely, tetrameric.
Proanthocyanidins are a class of polyphenols found in many plants, such as cranberry, blueberry, and grape seeds. Chemically, they are oligomeric flavonoids. Many are oligomers of catechin and epicatechin and their gallic acid esters. More complex polyphenols, having the same polymeric building block, form the group of condensed tannins.
Procyanidins are members of the proanthocyanidin class of flavonoids. They are oligomeric compounds, formed from catechin and epicatechin molecules. They yield cyanidin when depolymerized under oxidative conditions.
Transcription regulator protein BACH2 is a protein that in humans is encoded by the BACH2 gene. It contains a BTB/POZ domain at its N-terminus which forms a disulphide-linked dimer and a bZip_Maf domain at the C-terminus.
Chebulagic acid is a benzopyran tannin and an antioxidant that has many potential uses in medicine.
The flavans are benzopyran derivatives that use the 2-phenyl-3,4-dihydro-2H-chromene skeleton. They may be found in plants. These compounds include the flavan-3-ols, flavan-4-ols and flavan-3,4-diols (leucoanthocyanidin).
A hydrolysable tannin or pyrogallol-type tannin is a type of tannin that, on heating with hydrochloric or sulfuric acids, yields gallic or ellagic acids.
The ellagitannins are a diverse class of hydrolyzable tannins, a type of polyphenol formed primarily from the oxidative linkage of galloyl groups in 1,2,3,4,6-pentagalloyl glucose. Ellagitannins differ from gallotannins, in that their galloyl groups are linked through C-C bonds, whereas the galloyl groups in gallotannins are linked by depside bonds.
Stachyurus is the only genus in the flowering plant family Stachyuraceae, native to the Himalayas and eastern Asia. They are deciduous shrubs or small trees with pendent racemes of 4-petalled flowers which appear on the bare branches before the leaves. The plants have leaves with serrate margins.
Purshia mexicana is a species of perennial flowering small tree in the rose family known by the common name Mexican cliffrose. It is native to western-northern Mexico, the region of the Sierra Madre Occidental cordillera.
Condensed tannins are polymers formed by the condensation of flavans. They do not contain sugar residues.
Quercus infectoria or the Aleppo oak is a species of oak well known for producing galls that have been traditionally used for centuries in Asia medicinally while also used in softening leather and in making black dye and ink.
Stenophyllanin A is an ellagitannin. It can be found in Cowania mexicana, Coleogyne ramosissima and Quercus stenophylla.
Casuarinin is an ellagitannin. It is found in the pericarp of pomegranates. It is also found in Casuarina and Stachyurus species and in Alnus sieboldiana.
Pedunculagin is an ellagitannin. It is formed from casuarictin via the loss of a gallate group.
Bicornin is an ellagitannin found in plants of the order Myrtales, including Trapa bicornis and Syzygium aromaticum (clove).
Sanguisorbic acid is a constituent of some ellagitannins. It is constituted by a hexahydroxydiphenic acid unit linked by an O-C bond to a gallic acid. The differences with its isomers, valoneic acid and nonahydroxytriphenic acid, are that the hydroxyl that links the hexahydroxydiphenoyl (HHDP) group to the galloyl group belongs to the galloyl group in valoneic acid, while in nonahydroxytriphenic acid, the hexahydroxydiphenic acid unit is linked by a C-C bond to gallic acid.
Tellimagrandin I is an ellagitannin found in plants, such as Cornus canadensis, Eucalyptus globulus, Melaleuca styphelioides, Rosa rugosa, and walnut. It is composed of two galloyl and one hexahydroxydiphenyl groups bound to a glucose residue. It differs from Tellimagrandin II only by a hydroxyl group instead of a third galloyl group. It is also structurally similar to punigluconin and pedunculagin, two more ellagitannin monomers.
