Quercitron bark

Querzitronrinde, /. quercitron bark. Querzusammenziehtmg, /. lateral contraction. Quetsche,/. squeezer, wringer, presser, crusher plum. 

Old fustic Quercitron bark Persian berries Clorophora tinctoria L. Quercus velutina L. Rhamnus family Luteolin + Apigenin Genistein... 

This forms either dark brown, shining lumps or a more or less dense brown liquid. Under the names of flavine and quercetin, products are sold which are obtained by chemical processes from quercitron bark and represent the more or less pure colouring matter in the form of yellow or brown powder or paste. 

A good flavine should have a colouring power about sixteen times as great as that of quercitron bark. 

Fustic, quercitron bark, weld, flavine, alizarine yellow A and C. gallofla vine. etc. 

Quercitrin is the colouring-matter of the dyewood known as quercitron bark, obtained from Quercus tinctoria. 

The naturally occurring llavones are yellow and are very widely distributed in plants. They accumulate in almost any part of a plant, from the roots to the flower petals. Unlike the anthocyanins, which are too reactive and short-lived, the much more stable llavones have, from time immemorial, been used as dyes, for they impart various shades of yellow to wool. As an example, the inner bark of one of the North American oaks, Quercus velutina, was a commercial material known as quercitron bark and much used in dyeing it contains quercetrin. The corresponding aglycone, quercetin, is one of the most widely occurring flavones, found, for example, in Chrysanthemum and Rhododendron species, horse chestnuts, lemons, onions and hops. 

Flavin, flavine A dye prepared from quercitron bark. 

Quercitron bark Bark of the black oak Ouercus veluirlna, used in tanning and dying. 

USE Has been used as textile dye. Flavine yellow shade Is prepared by extracting quercitron bark with high pressure steam and consists mainly of quercitrin Tisdale, Con. Textile J, 57, 44 (1941). 

F. and flavonols are vacuolar pigments with a high absorption from 240 to 270 nm and 320 to 380 nm, i.e. they are yellow their frequent occurrence with anthocyanins leads to red and yellow flower colors. They used to be used in dying and printing, especially those from quercitron bark, old fustic (Chlorophora tinctorla L.), buckthorn berries and camomile. 

Bancroft adapted a technique for receiving a scarlet from cochineal...by impregnating it with a muriatic solution of tin, and a certain portion of yellow colour from the quercitron bark . This procedure, which had been successful for... 

Given Bancroft s patent on the quercitron bark, this may not have been an impartial part of the... 

Old fustic from the heartwood of Chlorophora tinctoria (Moraceae) of central America and young fustic from Rhus cotinus (Anacardiaceae) were used in the middle of the 17th century to produce a range of light-stable olive-yellow to gold shades depending on the mordants. Similar colors were obtained with quercitron bark (Quercus discolor, Fagaceae) of the USA. 

Salter (1869) describes this as follows brown pink, brown Stil de Grain, citrine lake, or quercitron lake is usually prepared from the berries of Avignon (ramnus infectorius), better known as French, Persian, or Turkey berries but a more durable and quicker drying species is obtained from the quercitron bark... In eifrier case it is a lake, precipitated from the alkaline decoction by means of alum, in such proportions that the alkali shall not be more frian half saturated. The excess of soda or potash employed imparts a brown hue. Tingry (1804) describes a brown Dutch pink ( .v.) which has intense colour due to the use of pure clay as substrate. Heaton (1928) also lists brown pink, although as a pigment that is obsolete or of little importance at that time. 

The former are mostly derived from plants [vegetabty colours) and may be contained in woods (e.g., campeachy, Brazil wood, sandalwood, yellow wood, fustic), barks (quercitron), roots [madder, turmeric), leaves (indigo, woad), flowers [safflower), fruit (Persian berries) and lichens [archil). Far fewer are animal colours [cochineal, kermes). 

Carlyle (2001) considers the composition to be unclear, alfliough it may have been a cpiercitron lake pigment (lake formed from quercitron, flie inner bark of the oak Quercus tinctoria). 

Flavonoids group Quercitron Vaccinium Walnut Apple-tree bark Colour Index (1971) Schweppe (1992) 331 Thompson (1935) 415, n.l... 

Quercitron Quercitrin CjiHjoO, Inner bark of Quercusoak... 

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