Quercitron

Quercitron

Quercitron is a yellow dye obtained from the bark of the Eastern Black Oak ("Quercus velutina"), a fine forest tree indigenous in North America. The name is a shortened form of quercicitron, from Latin "quercus", oak, and "citron", lemon, and was invented by Dr Edward Bancroft (1744-1821), who by act of parliament in 1785 was granted special privileges in regard to the importation and use of the substance. The dyestuff is prepared by grinding the bark in mills after it has been freed from its black epidermal layer, and sifting the product to separate the fibrous matter, the fine yellow powder which remains forming the quercitron of commerce. The ruddy-orange decoction of quercitron contains quercitannic acid, whence its use in tanning, and an active dyeing principle, quercitrin, C21H20O12. The latter substance is a glycoside, and in aqueous solution under the influence of mineral acids it yields quercetin, C15H10O7, which is precipitated, and the methyl-pentose rhamnose. Quercetin is a crystalline powder of a brilliant citron yellow color, entirely insoluble in cold water and dissolving only sparingly in hot water, but quite soluble in alcohol. Either by itself or in some form of its glucoside quercitrin, quercetin is found in several vegetable substances, among others in cutch, in Persian berries ("Rhamnus cathartica"), buckwheat leaves ("Fagopyrum esculentum"), Zante fustic wood ("Rhus cotinus"), and in rose petals. Quercitron was first introduced as yellow dye in 1775, but it is principally used in the form of flavin, which is the precipitate from a boiling decoction of quercitron and sulfuric acid. Chemically, quercetin is a member of a fairly extensive class of natural coloring matters derived from phenyl benzoyl-pyrone or flavone, the constitution of which followed on the researches of St von Kostanecki, A. G. Perkin, Herzig, Goldschmidt and others. Among the related, coloring matters are: chrysin from poplar buds, apigenin from parsley, luteolin from mignonette and dyer's broom, fisetin from young fustic and yellow cypress, galangin from galangal root, and myricetin from "Nageia nagi".

References

*1911


Wikimedia Foundation. 2010.

Игры ⚽ Нужно сделать НИР?

Look at other dictionaries:

  • quercitron — [ kɛrsitrɔ̃ ] n. m. • 1806; en angl. 1784; du lat. quercus « chêne » et citron ♦ Chêne de l Amérique du Nord dont l écorce fournit un colorant jaune (⇒ quercitrin). ● quercitron nom masculin (latin quercus, chêne, et citron) Nom usuel du chêne… …   Encyclopédie Universelle

  • Quercitron — Saltar a navegación, búsqueda Quercitrin (ESTRUCTURA DE L ramnosa IS WRONG; Lo que se muestra es D manosa). Quercitron es un amarillo colorante obtenida de la corteza del Negro roble (Quercus velutina), una multa de bosques árbol indígenas en la …   Wikipedia Español

  • Quercitron — Quer cit*ron, n. [F. quercitron, the name of the name of tree; L. quercus an oak + citrus the citron tree.] 1. The yellow inner bark of the {Quercus tinctoria}, the American black oak, yellow oak, dyer s oak, or quercitron oak, a large forest… …   The Collaborative International Dictionary of English

  • Quercitron — Quercitron, die gemahlene Rinde der nordamerikanischen Färbereiche (Quercus tinctoria), ein gelbes, zum Gelbfärben benutztes Pulver; es enthält ein eigenthümliches Pigment, das Quercitrin (Quercitrongelb, Rutin, Rutinsäure), ein Glykosid, welches …   Pierer's Universal-Lexikon

  • Quercitron — (Quercitronrinde, Färberrinde), die von der äußern schwärzlichen Schicht befreite und gemahlene Rinde der Färbereiche (Quercus tinctoria Barts.), deren beste Varietät vom Champlainsee bis Georgien wächst. Eine andre Varietät in Georgien und… …   Meyers Großes Konversations-Lexikon

  • quercitron — [kwʉr′si trən, kwər sit′rən] n. [< ModL quercus < L, oak (see QUERCETIN) + CITRON] 1. the inner part of the bark of a North American black oak (Quercus velutina), containing tannin and used in tanning and dyeing 2. a yellow dye made from… …   English World dictionary

  • quercitron — Quercitrin Quer cit*rin, n. [Cf. F. quercitrin. See {Quercitron}.] (Chem.) A glucoside extracted from the bark of the oak ({Quercus}) as a bitter citron yellow crystalline substance, used as a pigment and called {quercitron}. [1913 Webster] …   The Collaborative International Dictionary of English

  • Quercitron — Färber Eiche Färbereiche Systematik Klasse: Dreifurchenpollen Zweikeimblättrige (Rosopsida) Unt …   Deutsch Wikipedia

  • quercitron — noun 1. a yellow dye made from the bark of the quercitron oak tree • Hypernyms: ↑dye, ↑dyestuff 2. medium to large deciduous timber tree of the eastern United States and southeastern Canada having dark outer bark and yellow inner bark used for… …   Useful english dictionary

  • quercitron — noun Etymology: blend of New Latin Quercus and International Scientific Vocabulary citron Date: 1794 1. a large timber oak (Quercus velutina) chiefly of the eastern and central United States 2. the bark of the quercitron that is rich in tannin… …   New Collegiate Dictionary

Share the article and excerpts

Direct link
Do a right-click on the link above
and select “Copy Link”