Tannins are a class of astringent, polyphenolic biomolecules that bind to and precipitate proteins and various other organic compounds including amino acids and alkaloids.
Quercus alba, the white oak, is one of the preeminent hardwoods of eastern and central North America. It is a long-lived oak, native to eastern and central North America and found from Minnesota, Ontario, Quebec, and southern Maine south as far as northern Florida and eastern Texas. Specimens have been documented to be over 450 years old.
Food coloring, color additive or colorant is any dye, pigment, or substance that imparts color when it is added to food or beverages. Colorants can be supplied as liquids, powders, gels, or pastes. Food coloring is commonly used in commercial products and in domestic cooking.
Quercus velutina, the black oak, is a species of oak in the red oak group, native and widespread in eastern and central North America. It is sometimes called the eastern black oak.
A glucoside is a glycoside that is chemically derived from glucose. Glucosides are common in plants, but rare in animals. Glucose is produced when a glucoside is hydrolysed by purely chemical means, or decomposed by fermentation or enzymes.
Tannic acid is a specific form of tannin, a type of polyphenol. Its weak acidity (pKa around 6) is due to the numerous phenol groups in the structure. The chemical formula for commercial tannic acid is often given as C76H52O46, which corresponds with decagalloyl glucose, but in fact it is a mixture of polygalloyl glucoses or polygalloyl quinic acid esters with the number of galloyl moieties per molecule ranging from 2 up to 12 depending on the plant source used to extract the tannic acid. Commercial tannic acid is usually extracted from any of the following plant parts: Tara pods (Caesalpinia spinosa), gallnuts from Rhus semialata or Quercus infectoria or Sicilian sumac leaves (Rhus coriaria).
Copper(II) oxide or cupric oxide is an inorganic compound with the formula CuO. A black solid, it is one of the two stable oxides of copper, the other being Cu2O or copper(I) oxide (cuprous oxide). As a mineral, it is known as tenorite, or sometimes black copper. It is a product of copper mining and the precursor to many other copper-containing products and chemical compounds.
Luteolin is a flavone, a type of flavonoid, with a yellow crystalline appearance.
Traditional dyes of the Scottish Highlands are the native vegetable dyes used in Scottish Gaeldom.
Quercitrin is a glycoside formed from the flavonoid quercetin and the deoxy sugar rhamnose.
Kermes is a red dye derived from the dried bodies of the females of a scale insect in the genus Kermes, primarily Kermes vermilio. The Kermes insects are native in the Mediterranean region and are parasites living on the sap of the host plant, the Kermes oak and the Palestine oak.
Phlobaphenes are reddish, alcohol-soluble and water-insoluble phenolic substances. They can be extracted from plants, or be the result from treatment of tannin extracts with mineral acids. The name phlobaphen come from the Greek roots φλoιὀς (phloios) meaning bark and βαφή (baphe) meaning dye.
Stil de grain yellow or sap green is a pigment derived from berries of the buckthorn species Rhamnus saxatilis, which are commonly called Avignon berries or Persian berries after two historical areas of supply; latterly Italy was a major source. The color, whose principal chemical component is rhamnetin, was formerly called pink ; latterly, to distinguish it from light red "pink", the yellow "pink" was qualified as Dutch pink, brown pink, English pink, Italian pink, or French pink — the first three also applied to similar quercitron dyes from the American eastern black oak, Quercus velutina. Other names are Persian berries lake, yellow berries and buckthorn berries.
Reseda luteola is a flowering plant species in the family Resedaceae. Common names include dyer's rocket, dyer's weed, weld, woold, and yellow weed. A native of Europe and Western Asia, the plant can be found in North America as an introduced species and common weed. While other resedas were used for the purpose, this species was the most widely used source of the natural dye known as weld. The plant is rich in luteolin, a flavonoid which produces a bright yellow dye. The yellow could be mixed with the blue from woad to produce greens such as Lincoln green.
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.
Quercitannic acid is one of the two forms of tannic acid found in oak bark and leaves. The other form is called gallotannic acid and is found in oak galls.
Natural dyes are dyes or colorants derived from plants, invertebrates, or minerals. The majority of natural dyes are vegetable dyes from plant sources—roots, berries, bark, leaves, and wood—and other biological sources such as fungi.
Dyeing is the craft of imparting colors to textiles in loose fiber, yarn, cloth or garment form by treatment with a dye. Archaeologists have found evidence of textile dyeing with natural dyes dating back to the Neolithic period. In China, dyeing with plants, barks and insects has been traced back more than 5,000 years. Natural insect dyes such as Tyrian purple and kermes and plant-based dyes such as woad, indigo and madder were important elements of the economies of Asia and Europe until the discovery of man-made synthetic dyes in the mid-19th century. Synthetic dyes quickly superseded natural dyes for the large-scale commercial textile production enabled by the Industrial Revolution, but natural dyes remained in use by traditional cultures around the world.
Sì miào wán or the four marvels is a remedy used in Traditional Chinese medicine. It is available in powder and pill form. It contains, among other things, quercetin, berberine, and achyranthine.
