View source for Quercitron

{{Short description|Natural dye from the bark of the species Quercus velutina}}
{{distinguish|quercitrin}}
[[Image:Quercitrin.png|thumb|upright|Chemical structure of [[quercitrin]], the active dyeing principle of quercitron]]
[[File:Quercitron bark.jpg|thumb|upright|Powdered quercitron]]

'''Quercitron''' is a [[yellow]] [[natural dye]] obtained from the bark of the [[Eastern Black Oak]] (''Quercus velutina''), a forest [[tree]] indigenous in [[North America]]. It was formerly called '''Dutch pink''', '''English pink''', or '''Italian pink'''.<ref>{{cite dictionary |title=Oxford English Dictionary |edition=1st |chapter-url=https://archive.org/details/newenglishdic07murruoft/page/885 |entry='''pink''', ''sb.''<sup>5</sup>  |volume=7 |page=885 |access-date=12 January 2020}}</ref>

The name is a shortened form of quercicitron, from [[Latin]] ''quercus'', oak, and ''citron'', lemon, and was invented by [[Edward Bancroft]] (1744–1821), who by act of Parliament ([[25 Geo. 3]]. c. 38) 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 [[bark mill|mill]]s after it has been freed from its black [[Epidermis (botany)|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 (leather)|tanning]], and an active dyeing principle, [[quercitrin]], C<sub>21</sub>H<sub>20</sub>O<sub>11</sub>. The latter substance is a [[glycoside]], and in aqueous solution under the influence of mineral acids it yields [[quercetin]], C<sub>15</sub>H<sub>10</sub>O<sub>7</sub>, which is precipitated, and the methyl-[[pentose]] [[rhamnose]].<ref name="EB1911">{{Cite EB1911|wstitle=Quercitron |volume=22 |page=742}}</ref>

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 [[catechu|cutch]], in Persian berries (''[[Rhamnus cathartica]]''), [[buckwheat]] leaves (''Fagopyrum esculentum''), Zante fustic wood (''[[Rhus cotinus]]''), and in [[rose petal]]s.<ref name="EB1911"/>

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 [[Stanisław Kostanecki]], [[Arthur George Perkin|A. G. Perkin]], [[Josef Herzig|Herzig]], [[Heinrich Jacob Goldschmidt|Goldschmidt]] and others. Among the related, coloring matters are: [[chrysin]] from [[Populus|poplar]] buds, [[apigenin]] from [[parsley]], [[luteolin]] from [[Reseda (plant)|weld, mignonette]] and [[dyer's broom]], [[fisetin]] from young fustic and [[yellow cypress]], [[galangin]] from [[galangal]] root, and [[myricetin]] from ''Nageia nagi''.<ref name="EB1911"/>

In [[Iowa]] in the late 1840s and early 1850s, according to the historian Philip Dillon Jordan:

{{blockquote|Weld, fustic, and quercitron bark were carried as staple items in drug stores and general merchandise establishments. Sometimes, the physician kept a small supply of dye stuffs. It was not too uncommon, indeed, to find a jar of indigo next to a laudanum bottle and a box of quercitron associating with unrefined quinine.<ref>{{cite journal|author=Jordan, Philip D.|title=With Dyed Garments|journal=The Palimpsest|volume=25|issue=3|year=1944|pages=82-89|url=https://pubs.lib.uiowa.edu/palimpsest/article/id/24897/}} (quote from p. 86)</ref>}}

==References==
{{reflist}}

{{Glycosides}}

[[Category:Flavonoid glycosides]]
[[Category:Plant dyes]]